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hka93h
|
Why is so dang hard to take a good picture of the moon in the night sky?
|
Technology
|
explainlikeimfive
|
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"What are you using? A smartphone, an entry-level point-and-shoot, a mid-range mirrorless, a professional DSLR? This is the most important question. The next most important question is: are you using a tripod? The moon moves and your hands shake, so using a tripod will make your shots a lot better. If you have a camera with manual settings control, general consensus on appropriate settings will be ISO 100, aperture in the range of f/8-f/11, and shutter speed of around 1/100-1/150."
],
"score": [
3
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"text_urls": [
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|
[
"url"
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[
"url"
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|
hka9op
|
What is a 1X signal and how does it compare to 3G, 4G and 5G?
|
I uderstand it is the oldest signals still used but what exactly is it and was the a 2X or 2G?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Before 3G it was EDGE but could be referred to as 2G and before that was GSM which I guess we’d say was 1G. That’s what I remember seeing on my phones on the top left throughout the years as it progressed anyway. For whatever reason, they started referring to the generation by number at 3G (3rd generation)."
],
"score": [
4
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"text_urls": [
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|
[
"url"
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[
"url"
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hkdzv7
|
How do television networks know viewer statistics?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"There is a small statistically significant sample size of selected viewers who agreed to have a box connected to their TVs which measures their TV watching behavior. Then it’s a simple matter of extrapolation.",
"Ha! I was asking myself the same question a couple months ago. Apparently the TV company selects a sample of (consensual) families who get a special device that is able to record their activity and info about them and to send it to the company. They all register and when they turn on the TV they select their profile, so that there’s also information about who’s watching what. In the end, they get paid",
"Many replies talking about the old systems, where a sample of random viewers would have devices that report back to the company... But the 1990s are over, and now that isn't really true. In reality, in many cases today your cable box is straight up telling the cable company what you're watching, at all times, so long as the tv is on. The consequences of this are pretty wild. For example, a decade ago a friend of mine was interning at Google. She was working on the \"TV ads\" team. Google had bought up the ads to an entire cable company in < state > in return for the data of what people were watching. Based on the data, targeted ads were shown. If you and your neighbor watched the same channel, you got different ads. Or at least that was the plan. That was ten years ago. Can't imagine how complex it is now. URL_0",
"As already stated in other comments, there are measurement boxes (called people meters) or booklets. Alternatively, maybe more common nowadays, smart TV's and your box receiving and transcoding signals from satellites are connected to the Internet, so it can report stats. Also, the content might be delivered directly through the Internet on-demand in a case of IPTV and OTT. \"On-demand\" means that when you choose channel (IPTV) or a movie (e.g. Netflix), a request is sent to the provider and they send you back the content. Just like on Youtube. So providers have very precise statistics about what content flows through the network out of their servers. They know what do you watch, how long do you watch, if you switch the channel during ads and so on."
],
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8
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"https://www.quora.com/Does-the-cable-company-know-what-I-am-viewing-on-my-TV-What-do-they-do-with-that-information"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hkf19x
|
why aren't decentralized apps more popular?
|
Is it an engineering or adoption issue?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"A centralized app is usually easier to write and easier to operate. Reddit is centralized, and that makes it dead simple to use. All I have to do is load up the web browser and I'm done. If I wanted to use a decentralized version of Reddit, I'd probably have to have an instance of the distributed Reddit and run it locally. I'd have to have at least a bit of understanding about how distributed Reddit works. That's going to be a barrier to entry for some (maybe a lot of) people. Email is technically a distributed system, but even that has tended towards centralized services like Gmail. Hardly anyone runs their own email servers. Distributed systems are hard to monetize. Facebook and Reddit being centralized, mean that each of those companies has a lot more control over those systems. If Facebook were distributed, then parts of the Facebook Network would be outside of Facebook's control. If another Facebook Network provider becomes popular, then they could actually be in competition with Facebook for revenue. It's rare that a company would deliberately create competition for themselves like that.",
"I looked into some of such apps, long ago. There are many problems: **Storage**. If you're talking about storing data semi-permanently, you also need distributed storage. That's usually done by contributing some amount of disk space to the network. Some systems allow you to \"pin\" whatever you want. Some, like Freenet in my understanding are sort of probabilistic: you upload stuff, but have no control over where it goes. It might remain in the network, or not. Storage is also very unreliable. People turn off their computers, lose interest, lose data, etc. Typically there's some sort of propagation and caching. This means that if you have something everyone likes, it'll probably stay. Upload something of little interest and it quickly vanishes. So the network as a whole heavily suffers from bit rot, and prioritizes popular content like porn over more useful things that are less immediately interesting. Storage may be very limited capacity, since content needs to be extensively duplicated, and users may not be contributing enough. **Networking**. Distributed networking is messy. Failures are common. Low bandwidth and high latency are common. Distributed networking also tends to consume mass amounts of bandwidth, something an ISP might be unhappy with. **Lack of regulation**. If there's no central authority that can tell you that your politics are unwelcome, there's no central authority to tell anybody spam is unwelcome. The network can be easily attacked by uploading mass amounts of junk. Forums and such can be spammed directly. Distributed storage can be attacked by uploading mass amounts of junk that will push out the more interesting data. **Bad communities**. Guess who's most willing to tolerate all this? All kinds of not so nice people. The network will tend towards illegal content, drugs and crazy politics. Nobody with normal interests really needs to bother with putting up with all the limitations, so you get people who do have good reasons. **Lack of altruism**. Participating in a distributed network requires contributing resources that are not to personal benefit, and might even go against personal benefit (from slowing down your connection, to endangering the user legally). It doesn't help that the main audience for such things isn't that altruistic. **Limited growth**. The networks get quickly found out by hardcore adherents and then... nothing much seems to happen. Probably because a lot of people find such cesspits unpleasant to wade through, and eventually even the hardcore adherents start realizing that mentioning such places in polite conversation doesn't look good."
],
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4,
4
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|
[
"url"
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[
"url"
] |
hkfk0e
|
What are all the Things A.I.s can do at the moment? What about the near future? And After?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"No one can cover ALL of AI, but there are some fun tidbits. AI became the strongest chess engine by playing itself(both AlphaZero and LC0 pulled off the feat). The same AI will troll the opponent to simplify the game into a 100% winning position to avoid potential stalemates when the opponent only has the king. Even a medium human player would skip those 8 unnecessary moves and deliver checkmate. It's so loyal to the goal of winning as much as possible that it only 'cares' about efficiency when it matters. AI is able to find 'bugs' in games and exploit them. AI also fails to perform basic functions that humans understand very well, such as walling off a base in Starcarft 2. AI physics simulations are much more efficient than the traditional methods. Expect graphics to become much better while using less GPU. I expect AI to make weather prediction and traffic control obsolete professions. The most interesting part about AI, for me at least, is that it has the potential to become the best student we've ever seen, and the worst teacher ever imagined. It's nearly impossible to probe the weights and figure out WHY it does such and such. I'd recommend [ URL_0 ]( URL_0 ) for some great videos about AI.",
"Ill just give an example of AI that I found borderline creepy and next level. Even Im unsure as to how to feel about this one, but its there. Its called [ URL_0 ]( URL_0 ) and its exactly what it says it is. It uses an algorithm that can generate random pictures of people's faces. Faces that did not exist seconds before you visited the website and will be gone after you hit refresh. To be able to imagine a face like that, with that convincingly, thats a superpower. right?"
],
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"https://www.youtube.com/user/keeroyz"
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"url"
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[
"url"
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|
hkg6j2
|
I've learned that video game 'clipping' is caused by high velocity, thin colliders, and too-slow physics updates. Why are terrain surfaces in most 3D video games paper-thin? Why isn't terrain given extra fill/thickness inside and under it to prevent 'falling through the map into the void'?
|
I could see why you might not want to fill under the terrain in a game that features things like underground caves, but thin terrain seems to be present in a huge majority of 3D games (even those without underground features) and is not engine-specific. Why is terrain almost always a fragile piece of origami that's so easily punctured?
|
Technology
|
explainlikeimfive
|
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"So game engines already do this or they would never work at all. The collision engine checks \"which side of this triangle am I on?\" But if you build one of these engines you quickly find that a hard check clips all the damn time. So you add what's called an \"epsilon\" to the check. Essentially as you say your wall \"thickness\" - if something jumped past the wall in my calculation of where it was \"supposed\" to be, but not by that much, treat it as still outside/touching the wall and move it back outside. Some games do this by just moving things back immediately, some essentially put little \"springs\" on the object to \"pull\" it back outside. You can technically make that epsilon as big as you want! But then - you can't make any feature thinner than it. Like, if you want to walk on the roof and in the attic - too thick and it keeps kicking you up to the roof. Also the springs solution (which is otherwise generally simpler/more general) can have weird effects when you're too far from the surface - stuff that clips too far immediately gets *launched* back in the other direction. Sort of like the difference between walking and jumping on a trampoline. You can try to track things more granularly but it all comes down to tradeoffs in performance vs dev time vs accuracy. And there's always some situation the designers didn't think of - like a tire that shoots off at mach 4 when you place it in a whole pile of grenades. In the end, computer physics is limited by its sample rate. If you're doing physics at 30 fps, that tire moved *~~11~~ 45 meters* since your last update. You can sample faster, but then you're making the game slower. FWIW, some games have special logic for \"terrain\" that treats it as \"infinitely thick\" - but then your terrain and your building floors work differently, and caves and overhangs become problematic. Source: software dev, wrote several game-style physics/collision systems in college.",
"One important thing to note is that surfaces don't have thickness, it's a bunch of triangles stringed together. This makes it that if your character intersects with one of those triangles the physics engine starts calculating if and how it should push you away. So in short, it's actually a bunch of 2d surfaces spanned in a 3d world",
"In short, \"because it's expensive\". I've written some software that needed to do it \"right\", and it's a lot slower. The correct way to avoid clipping is an algorithm that looks like this: - Draw a line from my position last frame, to my position now - For every triangle of every surface, calculate if the line crosses the triangle. (Note: this is surprisingly inexpensive if you do out the linear algebra. Still costs a few dozen mathematical operations though). - If no triangles were hit, you're fine. If one triangle was hit, collide with it. If more than one triangle was hit, choose whichever one was hit *first*, and collide with that one. - Depending on your collision algorithm (i.e. if you bounce off and still are moving), do the whole thing again based on your new start-point and velocity. Now, the problem is that this is insanely expensive for decently complex terrain. So, to make something functional, game engine designers need to cut some corners. The biggest one is to limit the area in which we look for triangles. The more triangles we can ignore, and the more efficiently we can ignore them, the faster it will be. The problem, of course, is that if we should have collided with something we ignored, we clip. The second thing we can do is cut down on how much math is involved. Instead of calculating the intersection between our previous and current position with the triangle, we just check if we're near (and on the wrong side of) the triangle. It's a lot faster, but can (in some cases) cause somewhat weird artifacts. You will note that both of these methods include tunable parameters: the designers need to pick the correct balance between better game performance, and the edge-case of clipping. Usually this is set so that in normal gaming, you don't have clipping problems; those only come up when a player does something extremely weird.",
"Terrain is technically just a picture that is shaped and textured. If computers had the processing power to handle an engine that could also handle rendered terrain being made in layers to provide that 'thickness' it would be more commonplace. It's cheaper and a lot less consuming both on time and power to place an invisible wall where the terrain and objects begin than to render that many things just to avoid some clipping. All comes down to the programming as to how often it does or does not happen",
"In older games like Mario 64 they didnt do sweep tests. They did per frame checks. They assumed you couldn't get enough speed to move fast enough in a single frame to move through a surface. Insert the backwards stairs jumping trick and you gain enough velocity to go through walls. Modern games will parameterize the collision check by time (t0 and t1) and detect when/if the collision happened.",
"Everything is a trade off. Cut a corner here, a little more detail there. Design and optimization is a balance to get the best overall quality.",
"Disclaimer: The following could potentially be wrong: As far as I know, all 3D Models are created in such a way that they don’t have thickness. Basically all you model are the things visible to the player and only the outermost layer. The surface of the model is divided into smaller so called faces. These faces have an orientation (normals) which basically determines the direction it has to be viewed. This is especially true when used in videogames, since they only render the side you should look at, making the model see-through from the other direction. However, unless anything went wrong, you should never see this. To model in a way, that accounts for mistakes made elsewhere is a bad Idea in my book, not to mention the extra work needed to make it and for the game to render it. tl,dr: Models are paper thin because you only model what you can see and to save ressources. Ps: To prevent such glitches you should work on the update-order (check beforehand if a transform is possible) and make the colliders big enough. Modeling with density wouldn’t prevent the issue and would probably lead to a black screen (within material there is little light).",
"Usually, collisions are handled between the surfaces of objects. This is relatively simple and boils down to answering the question \"Do these two shapes intersect at this time?\" Time, however, has finite precison and is considered in finite steps (e.g. you might be checking 60 times per second). Any collision that occurs between those 1/60 second intervals wouldnt be detected until the next 1/60th of a second. If the game is not designed properly, you could have an object that moves from one side of a wall to the other side of the wall in 1/60th of a second and never actually intersects with the wall. The solution is to either use a smaller time step (which requires much more work to simulate the same amount of time) or to make a more complicated comparison like \"do these two shapes intersect at any time between the last time step and this time step?\" (which also requires more work). For example, bullets in first person shooters are often treated as lines that instantly go from the barrel of the gun to the bullet's impact point and that entire line is then compared against the world's geometry. However, this gets much more difficult when you're dealing with complicated objects and is too costly to be used for everything by default. Well-designed games are able to use the appropriate collision methods in the right situations and should not allow situations where objects have properties that can break the simulation.",
"You're thinking about the ground wrong. You're thinking about the surface of the ground as its volume, but those aren't the same thing. The ground in games is not necessarily thin, it's often quite thick - sometimes infinitely thick (ignoring technical details like integer limits). What does it mean for something to be thick? Think of the thickness defined by two flat surfaces, and the volume between them is considered the \"interior\", and the thickness is the distance between them. Any point between the coordinates of those surfaces is inside the object, otherwise it's outside. Now look at the ground in a video game. Sometimes it really is thin, even infinitely thin, so if a given volume does clip past it, you don't trigger any code to deal with clipping inside something, and instead you just \"fall\" until something else happens (you hit a kill plane, an integer overflows, etc.). This isn't necessarily a huge problem so long as you consider the collision detection and the size and speed of the objects that might collide with the ground. But often *all* points below the surface of the ground are considered inside the ground, and that thin \"origami\" isn't the geometry of the ground, it's the geometry of just one surface of the ground, and the ground is in fact so thick that *any* point below it is considered to be within it. If the whole world has a defined floor surface, you might simply clamp the vertical position of everything according to that surface instead of even checking for collision, which is functionally equivalent to doing collision detection checks with an infinitely thick ground. The thing that is tricking you is that, because we model things as rigid colliders, unless you're doing something like destructible terrain, we usually don't bother specifying what things look like on the \"inside\". If collision is rigid, and the camera is subject to collision, only the outside should ever be visible. So if you do manage to clip the camera into the ground (because the collision simulation fails), you discover that, unlike real-life solid objects, only the surface is visible, and often only one side of it. You could also just assume that inside of things, all light is blocked, so the screen should just be black, and occasionally games will do this, but that's useless to the player who accidentally clips inside something (and makes it harder for them to get the camera back out), and makes debugging potentially harder. So visually it looks kind of like the ground is thin, but *geometrically* the ground may actually be very thick.",
"Clipping is caused by high velocity. If velocity was not abnormal there would be no clipping, so efforts are focused on preventing abnormal velocity as it avoids both problems. If you fix the clipping you still have the abnormal velocity problem so the gameplay is still broken. Kind of like how a plane breaks apart when it crashes. Making the plane stronger to survive the crash is pointless as the plane shouldn’t crash in the first place.",
"First of all I'd like to add a quick explanation as to \\*why\\* high velocity colliders clip through surfaces. Consider this: Bullet (usually a prime example): o Wall: | These are the colliders of these two objects. What you usually do is check if the circle overlaps the line (the surface). What might happen though is this: Frame 23: o | Frame 24: |o In frame 24, we check for an intersection... but the bullet already went past the wall, so these simple (aka efficient) calculations couldn't see that it went \\*through\\* it. So RIP collision. There are of course solutions to this problem, a common one is to extend the collider: each frame, we make a big one that contains both the collider in frame 23 and the one in frame 24, like so: Frame 23: o | Frame 24: |o Check: Ϲ═╪Ͻ < please pretend it's a capsule There we go, now we have an intersection, good job us. Of course this is overly simplified, but that's the idea. The real algorithm is slighly more complicated and this additional \"complication\" makes it fairly more expensive than our first strategy where we only check the single collider, so we can't use it everywhere, we only use it for fast moving, small objects. Since the player shouldn't be either fast nor small enough to completely pass through the terrain in one frame, expecially since in most cases the player is taller than wider and... you know... you fall vertically of course... you avoid the more expensive strategy as it shouldn't be necessary.",
"Processing power simply put. Moving one image can be easy, but moving millions that are supposed to interact with each other(dent in a wall), requires too much effort and not enough reward for that process.",
"There really isn't such a thing as thickness per se in 3D models. Every object in any game you have ever played is simply an empty shell, and this shell is infinitely thin. Even accurate physics simulations with millions of particles are limited by the fact the particles can only be so small before it becomes impossible to process by any system that currently exists. Solid objects in the world have \"thickness\" because they are composed by trillions and trillions (and so on) of atoms, and you simply cannot make something anywhere close to a real solid object in digital. There are ways to get better collisions though, but I am nowhere smart or qualified enough to tell you how that's done.",
"It's because of how 3D models work. Everything in a game is made up of little triangles called polygons. The terrain is the biggest collection of polygons in the game world, and the more polygons an object has, the more processing power it takes to have it in the game, visible or not. The more processing power that the engine needs, the more likely the game will have frame rate issues. So I guess you could say that ironically, those terrains are paper thin to prevent the exact thing that they are causing.",
"Noting is ever filled, or (thick) everything is made from planes arranged into polygons. Everything is basically a shell.",
"In the 3D world there is no such thing as actual, solid thickness. Take a look at [this image]( URL_0 ) The first shape is a single flat plane. You can \"thicken\" it if you like (second shape), but in reality, if you actually looked inside it, you'll see it is still hollow (third shape). So if you try to thicken the terrain, you'll only be adding another thin plane underneath it, not actually thickening it.",
"Because you don't need to simulate the entire ground when the ground is meant to be completely static and unpassable; it only has to be a 2D plane that can not be passed. Making the ground thicker isn't as important as having the physics update more often, but that would slow the game down. Making the ground thicker may be faster, but it would also still end up with things clipping through part of it. Instead, you can just add another check that says if they are beyond the threshold, treat it as at the line instead of under it. Or they simply check that you're under the ground and teleport you to a safe spot, so you still see yourself fall through for a moment.",
"I'm going to chime in as a 2D game developer, although similar principles apply to 3D games. Imagine a bullet traveling at 600m/s being shot at a 5m thick wall. Assuming 60fps, the bullet will travel 10m every tick. So it you are just checking for point collisions every tick, then the bullet will be on one side of the wall one tick, and on the other side the next tick, completely bypassing it. What you need to do is, instead of checking for point collisions (∆x^2 + ∆y^2 < r^2 ), you need to check for line-to-circle, or line-to-line collisions. These aren't actually all that expensive, but the cost does add up. So the common sense approach is to do this for high velocity objects like railgun bullets or hitscan weapons, and use point collisions for most other things. Consider a shotgun that shoots 200 pellets per shot. You want to minimize the number of calculations you have for each of those projectiles. But if it is a sniper rifle that shoots once per second, you can go all in, and do precise collision checks all you want. Also, I mentioned hitscan weapons above. Those are actually great from a performance point of vjew, as you just calculate them once, instead of having to do it every tick. But for a regular high-speed projectile, you need to do calculations every tick. However, against static objects like terrain or props, you can still just do the whole calculation once, and note when the projectile will collide with terrain. Then, on every tick, you just need to check the projectile against the moving entities like players, enemies, etc to see if you hit anything before you hit the terrain. I know this doesn't directly answer the question, but I hope it provides some useful insight at least."
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hkh4bf
|
Why does feedback loop noise turn high pitched?
|
Technology
|
explainlikeimfive
|
{
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"fwspb3o"
],
"text": [
"IT has been asked before - URL_0 One reason is that performers and sound technicians like microphones that sound 'sharp' - ones that emphasize the high pitched sounds. But this also emphisizes the high pitched sounds in feedback, which is why the low frequencies in feedback get drowned out by the high ones."
],
"score": [
4
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|
[
"url"
] |
[
"url"
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|
hkhygy
|
How does a microphone works? how can it converts audio into digital?
|
Technology
|
explainlikeimfive
|
{
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"fwsr2ja"
],
"text": [
"There are a couple of different microphone types, mainly dynamic and condenser. I’ll explain the dynamic microphone, as that’s a bit easier to understand. The dynamic mic is basically the same as a speaker driver, but in reverse. The soundwaves make a membrane vibrate. There is a small coil of very thin copper wire attached to the membrane. When this coil moves near a magnet, a small electric current is induced in the wire, which will follow tje waveform of the soundwaves. This is then taken out of the microphone and amplified. The conversion from analog to digital happens in a separate unit called a A/D converter. Sometimes it’s built into the microphone (eg. USB microphones) The A/D converter works by sampling the voltage from the microphone many thousand times per second. 48 000 Hz is a common sampling rate in pro audio. This means that the converter measures the voltage 48 000 times every second and then assigns a binary value to it. If the bit depth is 24 bits, then one sample might be say 101100010011010101110110"
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6
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[
"url"
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[
"url"
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|
hki4ya
|
How did the old 'Etch a Sketch' Work
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwss6pq"
],
"text": [
"The same way the new ones work. The toy is a kind of plotter with pulleys inside. The inside surface of the glass screen is coated with aluminium powder, which is then scraped off by a movable stylus, leaving a dark line on the light gray screen. The stylus is controlled by the two large knobs, one of which moves it vertically and the other horizontally. Turning both knobs simultaneously makes diagonal lines. To erase the picture, the user turns the toy upside down and shakes it. Doing this causes polystyrene beads to smooth out and re-coat the inside surface of the screen with aluminum powder. The \"black\" line merely exposes the darkness inside the toy. Scraping out large \"black\" areas allows enough light through to expose parts of the interior."
],
"score": [
6
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[
"url"
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[
"url"
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|
hkly9z
|
Why did we go from 4:3 to 16:9?
|
Technology
|
explainlikeimfive
|
{
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"fwthvnb",
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],
"text": [
"In the first half of the 20th century, movies were filmed in 4:3 or close to it. When television became popular in the 1950s, the film industry saw it as competition and started looking for gimmicks to keep people coming back to theaters. So they started filming in \"widescreen,\" using a number of different formats (1.85:1, 2.35:1, etc., even up to 3.5:1 and higher). A few decades later they invented HDTV, which was based not necessarily on film but on electronic video. It helped to have a ratio that was not only easy for display and programming but also that could comfortably fit *all* the various aspect ratios currently in use with maximal efficiency. 16:9 was the closest ratio that could accommodate this need, and it became standard in the industry very quickly.",
"It better matches the aspect ratio of movies. So when the new standard of hi-def was created, they had the opportunity to make the home experience match the movie experience.",
"There used to be a lot of different aspect ratios around the world. 4:3, 5:3, 1.85:1, 2.20:1, 2.35:1. Whenever you would convert something from one to another you had to throw away some stuff on the top/sides, or add black bars to the top/sides, depending on which was narrower. The 16:9 ratio came from combining all these existing ratios and finding a best-fit square that could fit nicely in the narrowest by shortest ratios, or encompass the tallest by widest ratios. Converting any media to this results in the minimum amount of loss or black-bar across the spectrum of existing standards."
],
"score": [
9,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hknfdv
|
How does Raytracing work, and why is it better than the current methods?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwtz0gx"
],
"text": [
"Traditional rendering (bilinear interpolation) is essentially a hack to fake something that looks ok on the screen. Basically every pixel draws itself with a texture/material lookup, a bit of tinting from lights, and doesn't interact with anything else. This makes transparency and reflection a fucking nightmare of hacks upon hacks to deal with. In ray tracing, each screen pixel fires a ray into the game. That ray may reflect, refract, and be absorbed in different amounts from every surface it touches using a real-world lighting equation. Each thing it interacts with influences the color of the resulting screen pixel. This is especially good for transparent and reflective objects. This ray traced picture has been up on Wikipedia for like 15 years and it's still showing better transparency and reflection than any game has: URL_0 Also bilinear interpolation is difficult to parallelize, where ray tracing is trivially parallelizable. Ray tracers are also easier to implement and maintain. Years ago as a student I built a ray tracer from scratch, with only about as much information as I posted in this comment. Building a triangle rasterizer (including triangle clipper etc...) on the other hand took two semesters of specialized instruction and most students failed that course."
],
"score": [
3
],
"text_urls": [
[
"https://upload.wikimedia.org/wikipedia/commons/e/ec/Glasses_800_edit.png"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hkva4s
|
Does a mouse send 1s and 0s to the computer?
|
I saw a video saying it tracks and images how the mouse traverses the surface? So does it tell the computer a chain of 1s and 0s to move the cursor?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwv6uen",
"fwvhqwd",
"fwv6sw2",
"fwvdtt6"
],
"text": [
"it does send 1s and 0s but ultimately what they are interpreted from are numbers that correspond to the change the image sensor at the bottom of the mouse picks up and of course whether the buttons are pressed. Your mouse shines an angled light at the mousepad or surface and the sensor next to it is like a tiny(like 18 x 18 pixels) camera that can see the tiny ridges on most surfaces and is always taking lots of little pictures really fast. By lining consecutive images up and looking for the tiny differences in these ridges it can do math as to how fast or far the user moved the mouse across a pad. It's constantly sending these math answers to the computer, and if you were to look at the memory of the mouse hardware it would be sending this information in binary(1s and 0s) ~~but depending on what you use to read this it could be abstracted into assembly language(which is like shorthand computer code)~~ or full integers of a direction and speed, and true and false for button presses.",
"Yes. So the details vary depending on the system, but this is generally what happens. Processors have a feature called an \"interrupt.\" This does exactly what it says, it's a mechanism for some device, be it a mouse, a keyboard, hard drive, etc to tell the processor that it has some new information for it. And there are small programs called an \"interrupt handler\" which are executed when a specific device signals an interrupt. The general process is this: 1. The processors is doing processor things. 1. The mouse is moved by the user. 1. The mouse triggers and interrupt. 1. The processors sees interrupt, and switches to run the mouse interrupt handler. 1. The mouse interrupt handler reads the signal coming from the mouse and puts it into some place in memory. 1. The processor goes back to what it was doing before being interrupted. Then any programs that wish to read mouse information will read that memory location continuously. The memory location contains information such as relative movement, which mouse button was clicked, and how many times it was clicked since the last poll, etc. Today, the situation is more complicated. Computers have the ability to allow peripherals to write directly to memory instead of interrupting the processors all the time rather than but the general concept is still the same. And programs generally wait for mouse events from the operating system, rather than polling memory locations for updates. In other words, a programmer today will tell Windows/OSX/Linux to run this code when a mouse click happens. Source: I found a book from the late 80s on programming mice at the library at work and kept it on my desk as a joke. Then I decided to read through it and learned a whole bunch about mouse programming and never had the opportunity to put it to good use until now.",
"Short answer is yes. Everything boils down to zeros and ones (off, on) also called bits, which group to create bytes. The mouse is an input device that’s one component of a standard operating system software interface that controls screen cursor movement along an X,Y grid and of course other mouse features like left and right click and scroll. It’s as simple as ones and zeros, but there are many levels of complexity that make it work.",
"Yes! The mouse has a sensor (or on old mice, a ball that rolls) that tracks the movement. Then, when it figures out which way the mouse moves for a particular moment, it sends that data as a sequence of 1s and 0s to the computer, which processes it and moves the arrow on the screen. But how can a bunch of 1s and 0s encode movement. Well, just one 1 or 0 (called a bit) isn't good for much. But if the computer checks 8 bits at a time, then they can represent more information. Think of all the different combinations of 0s and 1s you can make with just 8 of them. If you do the math, you can have 256 different combinations. This 8-bit chunk is called a byte. So, each of the different byte configurations can represent a number from 0 to 255, or, if the computer is made to read it a different way, a number from -127 to 128. So if the mouse sends just 2 bytes, those 16 1s and 0s can encode two different numbers. One of the numbers can tell the computer how much to move the arrow up and down, and the other can tell the computer how much to move it left and right."
],
"score": [
51,
14,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hkvbml
|
Why do some photos from the 19th and early 20th centuries appear to be of higher quality than photos from the mid to late 20th century?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwv4qby",
"fwv75ro"
],
"text": [
"Probably because they are. Good film with good photographers were able to capture very clear very detailed pictures, more detailed than digital cameras now, because the clearness of the picture is only held up by the molecules on the film, as opposed to how a digital camera is controlled by the number of pixels it can store. When old films get re-released as HD or 4K, they actually just go back and rescan the original film with better digital equipment to copy the detail of the film better.",
"Large format (8x10\") cameras in the hands of patient methodical professionals with specially set lighting produce better results than photos taken on high-sensitivity 35mm film on the go out in the world, regardless of the age they're from. If you had a camera in 1845, you were very special, and knew exactly how to use it to the best of it's abilities. Most of the photos taken in the 70s were taken by someone's dad who just wanted to enjoy family photos in crappy light, and the big names at the time weren't shooting slow deliberate large format photos, they were using small hand-held cameras with small film out in the world where the focus was on storytelling and adventure rather than technical quality and fine details."
],
"score": [
24,
13
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hkx2lf
|
when a video game glitches is it the game not understanding your actions or is it literally you breaking code with anomalies?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwvhs7e",
"fwvu2nv"
],
"text": [
"I'd define 3 types of glitches all of them are caused by the games programming logic not handling the data it's attempting to display well. The first kind are internal glitches. These are inherent to the games code. Typically these are the kind of glitch which make a game \"buggy\". They happen during normal intended play. Other glitches are player caused. Where the player creates a situation that the game's code can't just comprehend. If you ever watch speed running, this is the kind of glitch which allows for that sort of thing. No human could have reasonably foreseen a player acting in that way. Finally there are simple network glitches where an online game has problems with the internet it's attempting to use to transfer it's data to the games server and vice versa. Things like \"packet loss\" or simply a slow connection causing lag are common kinds.",
"A glitch is either code that's running in ways that weren't anticipated, or code that's running on parameters it wasn't designed to handle. If you manage to go out-of-bounds for example, the game is running code that assumes your within the game boundary and weirdness happens. So in answer to your question, it's the latter. You don't alter the code by playing the game, you run it. If you manage to run it when it shouldn't be run, glitches happen. Of course the code could also just be bad and night glitch under normal circumstances that the developers failed to test."
],
"score": [
8,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hkxtug
|
How are computers able to understand code?
|
What is it inside them that makes them able to understand what we say? If it is a piece of hardware, how does that work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwvmrnd"
],
"text": [
"It's both hardware and software. Computers speak one language and humans speak another. Code is the happy medium that helps us give commands to computers. At the core of the computer is its brain, the CPU. It speaks in 1s and 0s. We speak English etc. The two middle-man languages AKA our \"translators\" are assembly and high-level programming languages. High-level programming languages include C++ and python. Assembly is literally \"store This.\" \"Add That to This.\" \"Load That.\" These are the actual commands the CUP executes. Some super smart people write special programs called compilers that convert the high-level programs into the assembly that the CPU can understand."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hky7t7
|
Why does resetting the modem fix/improve the internet connection and speed?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwvqn1f",
"fwvsil8"
],
"text": [
"Rebooting a modem or router is just like if your computer is slow. Restarts up all it's boot processes, clears it's cache and what not. Resetting it would bring it back to default settings and it will pick up a new DHCP lease from your service provider as well",
"There are 2 types of memory. Permanent(the actual program) and temporary(cookies, etc...). When you reboot, you clear out the temporary memory, which may have been slowing you down. Either because it was being searched constantly for no reason, or there was some bad bits in there. Odds of working increase as the router stays on longer. Same with your browser. We call it 'clearing the cache'. I personally turn off my computer each day. Some people reboot every 2 weeks. To each their own."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hkzi2w
|
How are fireworks that create complex designs made?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwvxq96"
],
"text": [
"Basically by layering them like onions inside onions. The individual things that burn and make trails are little spherical pellets of gunpowder called stars. The gunpowder in the stars is tightly packed and glued together with a binder like starch to make them solid. Because it's solid each star will burn from the outside in so if the outermost layer of each star burned without color then deeper it was a red colored mix, and the center was sparkles, you'd get a dark spot in the middle when it goes off followed by red streaks then finishing with the sparkles. To propel them out the stars get packed around a sphere of loosely packed powder (wrapped in cardboard) making a shell. Because it's loosely packed, and confined in the cardboard it detonates instead of burning propelling the stars outward. To make shapes the stars are set into a pattern inside the sphere of loose powder. Stars closer to the center aren't thrown as far as the ones in the outside, so if you wanted, something like a smiley face just packing the stars in the shape of a face works pretty well. Getting the right orientation isn't really doable yet though so most shapes tend to be symmetric, or have multiple of the same shape shot at once so at least some will mostly be facing the right way. So no writing out letters. If you want more complicated patterns it's mostly a matter of setting up the layers correctly with time delay fuses in between each stage. And for lots of stuff you don't really even need spheres. Lots of fireworks are shaped like cylinders with stages that fire outward and burn from the bottom up."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl03w3
|
CPU threads and cores. Whats the difference? How do they work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwvzxgy"
],
"text": [
"A core is a hardware component. The difference between multiple CPUs and multiple cores is that multiple cores share some resources on the same cpu, like cache memory where multiple ~~cores~~ CPUs don't. It makes thing more compact and efficient overall. A thread is a software concept. It represents a specific programming task that needs to be done. Threads run mostly independently from each other though they can share information. As a very basic example on how threads are used with a simple unzip app one thread can handle user input on a gui and display progress bars, and a second thread can handle decompressing and loading actual files. Most GUIs work this way to make sure that the interface stays responsive (doesn't look frozen) even if it's doing processing in the background. In a bit more advanced program one thread can handle decompressing the first half of a file, and another the second half. There's also a hardware thing called hyper-threading where a single core can handle execution of multiple threads at the same time. It isn't as fast as having multiple cores because it doesn't have a complete copy of all the hardware needed to independently do different things, but it's still faster than just running a single thread on one core."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl1kmo
|
If FM radio sends data by changing the frequency of the radio waves, then how can different station broadcast at different wavelengths (say 99.00 MHz, 95.90 MHz and so forth)?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fww71j5",
"fww7ckp"
],
"text": [
"The frequency you tune your radio to is the baseline, or middle frequency. The transmitting station modulates off of that frequency by a set range, .05 MHz if I remember correctly. So a station transmitting FM on 90.0 MHz will actually transmit in the 89.95 - 90.05 MHz band. That's why radio stations are all set intervals apart, so they don't transmit over each other.",
"FM does indeed work by changing (or modulating) the frequency, but the amount by which it changes is very small compared to the frequency gap between stations. The allowed bandwidth of an FM radio station is about ±75 kHz, which is ±0.075 MHz. This means that a radio station with nominal frequency 99.00 MHz is actually using frequencies from 98.925 to 99.075 MHz. A station at 95.90 MHz is far away enough that there's no interference with it. In fact you could have a station as close as (roughly) 99.20 MHz without any interference, leaving them as distinct stations. In practice the stations are separated by much more than this, to make absolutely sure there's no overlap. The modulation carries the audio frequency information that is converted to sound waves by an FM receiver. Audio frequencies audible to humans are from 20 to 20,000 Hz, or up to 20 kHZ. So you only need 20 kHZ of modulation to encode the audio for a single channel. FM stations are given more (the ±75 kHz) to allow for stereo, and a bit of overhead."
],
"score": [
11,
8
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl3bc7
|
Why do YouTube ads load quickly with a poor internet connection but the actual video doesn’t?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwwlnj1"
],
"text": [
"YouTube has a zillion uploaded videos, many of them hours long, distributed across many servers and datacenters. Meanwhile, they only host a hundred or so video ads (very rough estimates here) which are generally short. The ads can be hosted by every one of their server clusters, but the video you're trying to watch might have to load from a specific server location somewhere around the world (depending on the video's popularity). These can be bottlenecked in various ways while attempting to deliver the video to you, either the server itself being overwhelmed or just some internet traffic congestion at a router between you and the server. As a vid grows in popularity, it may be transmitted to more data centers around the world, to provide faster / closer delivery to the video's larger audience."
],
"score": [
73
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl3cpv
|
What is the difference of a 32 bit and 64 bit system?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwwi60d",
"fwwigqf"
],
"text": [
"Basically the difference is a 32-bit system uses 32 “bits” of binary (32 pairs of either “1” or “0”). The biggest binary number you can have is 11111111111111111111111111111111. In a 64-bit system, it uses 64 bits of binary (11111111111111111111111111111111 11111111111111111111111111111111). This distinction has far-reaching consequences simply because there’s so much MORE you can do. The most visible difference is that 32bit systems can only access around 4gb of ram (because they literally run out of numbers to use as an “address” for the memory), while 64bit systems can (EDIT: theoretically) use ~1 billion GB of ram.",
"Kind of hard to do ELI5 but here goes ... The bits listed are the max number of address bits used to address memory. That's software, the hardware may not support all those address bits. In a 32 bit OS a program can address a MAXIMUM of up to about 4 billion bytes (4 GB) of space (program, data, buffers, scratch space, everything). In a 64 bit OS a program can potentially access 4 billion times THAT. More importantly, the OS can only access that much. So a 32 bit OS can only directly access about 4 GB of RAM. That's what the OS has to run the OS plus all running programs. That was LOTS a few years ago, not so much now. We runs lots of programs now and OSes have gotten much bigger. A 64 bit OS has potentially 4 billion times 4 GB. In practice it does not as the hardware only supports so much physical memory. It is possible to find hardware that supports thousands of GB of physical memory. A 64 bit OS could use all of that. A 32 bit OS would be able to access only 4 GB, ignoring the other thousands if GB. Does that help?"
],
"score": [
8,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl3y7g
|
how can a company take down a website that is owned by someone else due to something like DMCA
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwwmty9"
],
"text": [
"Nothing much to it. Their legal department sends a letter/email to the website host, saying \"Hi, we're Disney, we own this and that that's on your client's site\". The host reads the letter, and removes the material, or terminates the customer's account, because if they don't, they're at a very serious risk of being sued by Disney, and that's going to cost them more than the customer would ever give them. The DMCA does have a provision for the website's creator disputing the claim, but if you're really putting up somebody else's stuff on your website, that's not a great idea. Also technically the copyright owner pledges that they indeed own the content in question, though I'm not sure if anybody has actually ever gotten into trouble for just mass sending infringement notices without checking whether they're accurate."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl72e6
|
when the battery of an electronic toy is low, why does it repeat the beginning of a sound instead of only playing it less loudly?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwx5upb",
"fwx89n3"
],
"text": [
"This is most likely because the battery isnt completing the circuit to go through the entire sound. Basically every time the circuit breaks (battery gets too low) it will need to start from the beginning of its programmed sounds. I'm sure someone can elaborate farther.",
"Any lights or motors or speakers will draw a higher current from the battery. Weak old batteries won't be able to supply that amount of current, which means the circuit voltage drops. That can trigger a reset of a microcontroller. Some devices won't reset, because their microcontrollers have a built-in \"brown out\" detection module. That can trigger the electronics to pause or enter \"sleep\" mode, or do something else besides just reset."
],
"score": [
4,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl7r8t
|
How do search engines work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwxatof"
],
"text": [
"They keep a giant database of every webpage on the Internet, by using a program called a crawler that goes on every website and follows every link on that website, and eventually you have a pretty complete database. Then when you run a search for a key word, they search their database for websites that they have cached that contain your key word."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl83z7
|
How are transistors on a CPU made?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwxdef7"
],
"text": [
"It's difficult to ELI5 Basically it's a set of chemical and manufacturing processes to make transistors on a CPU. They are not made individually, but all at once through a layering technique on top of a prepared silicon wafer. URL_0 URL_1"
],
"score": [
3
],
"text_urls": [
[
"https://www.youtube.com/watch?v=35jWSQXku74",
"https://www.techspot.com/article/1840-how-cpus-are-designed-and-built-part-3/"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hl85ym
|
What's that wall of gibberish text when you open some type file in notepad?
|
"¾xàÏù" An enormous wall of basically **that** is what you can expect when you open up any type of random file in notepad that isn't meant to be in notepad. What is it? What happens if you just erase a random part of this gibberish? What is it representing and is there any way to comprehensively read it?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwxdv01",
"fwxoxwn",
"fwxritr"
],
"text": [
"You can classify computer files into two main types: text files and binary files. All computer files are just a big sequence of numbers -- or in computer terms, bytes. In a text file, each of these numbers is intended to corresponds to some human readable letter. For example, the number 65 usually corresponds to an \"A\". When you open these files in Notepad, it has an easy time translating each number to a letter for you to read. In a binary file, anything goes. It could be a picture where each number corresponds to a color of a pixel; it could be a database file where the numbers could mean all sorts of things.; it could be anything at all. When you try to open these files in Notepad, it will attempt to translate each number into a letter, but since that data is not intended to be interpreted that way, you wind up with gibberish.",
"Imagine you and your friend are talking via a special code - you substitute A for 1, B for 2, etc. So something like DAD would be 414 in your special code. If you give your friend a piece of paper with 414 written on it, your friend can translate that to mean word DAD. Now lets say your mom and dad also use a code to talk to each other, but they use a different code. For example, A = 0, B = 3, C = 14, etc. So if you give your mom the same piece of paper, she will try to translate 414 using her own code, and she will not get same result (\"DAD\"), but instead will get some other result. This is what happens. You try to use Notepad to open a file that was not meant to be opened by notepad. Notepad sees a bunch of code, and uses its own rules to translate it into text. The problem is, that bunch of code was not meant to be translated to text, so the result is not something you can understand or read.",
"Digital storage media don't store characters. They store bits, generally thought of as \"1s and 0s\". So how do you tell a computer to store a word like \"BAD\"? You devise a code that represents each letter in the language you're using as a sequence of bits. Maybe you decide A is 01000001, B is 01000010, C is 01000011 and D is 01000100. So you store BAD as 01000010 01000001 01000100. Great, but what if you want to store an image? Maybe you decide to represent the color of a pixel as the intensity of red, green and blue in it, using three bits for red, three bits for green and two bits for blue to get an 8-bit value for each pixel. Purple might be 01000010, and pink might be 10000010. There's nothing inherently wrong with either of these schemes, as long as the computer knows what type of information has been encoded in a binary sequence and what encoding scheme was used. To help computers read files correctly (and decode bits into information correctly) they usually store a special sequence of bits/bytes at the start of each file that indicates its type. What you're seeing when you open a non-text file in a text editor is its attempt to decode those special bytes and the binary data in the file as ASCII, Unicode or whatever text encodung standard it defaults to. Many of those binary sequences map to non-English characters (or even nonprintable characters) in the default encoding scheme."
],
"score": [
20,
5,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hl9979
|
How do graphics cards work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwxr5p8",
"fwxl3hk",
"fwxplt3",
"fwxudda"
],
"text": [
"A simple analogy I've seen is: CPU is like a race car; it can take a couple people somewhere very fast. GPU is like a bus; it can take a huge group of people somewhere less fast. People=calculations.",
"The CPU is made to calculate small tasks very quickly. GPUs are designed to be better at many calculations at once, but less efficiently. That makes them far better at doing the relatively simple, but simultaneous, calculations needed to render a 3D space. Meanwhile a CPU can be dedicated to chew through the more demanding calculations",
"Different hardware can be designed to do different things. The \"general purpose\" CPU in most computers is optimized for running complex procedural programs that are essentially a long sequence of instructions with branching. Get an instruction from memory, which may tell it to get a value from somewhere in memory, add it to a number from somewhere else in memory, and if the result is greater than 38, fetch an instruction from somewhere else in memory and run that. Most normal programs are executed in this fashion: Doing a computation that allows a decision to be made about what computation to do next. A modern program may involve doing this sequence a billion times in succession. A general-purpose CPU chip is very large, containing perhaps billions of transistors, consumes a lot of power, and generates a lot of heat. GPUs are optimized to do a different task, which is \"rendering\" a visual representation of some kind into special memory that is then read to present an image on a screen (generally a few bytes of memory per screen pixel). Doing this kind of work pixel-by-pixel using a general-purpose CPU is too slow for situations where a large display is presenting complex, rapidly-changing information. A GPU contains a large number of independent processing units that are designed to do the simple and repetitive tasks of rendering an image quickly, and then the job of painting the overall display is done in parallel by allocating the work among this large number of processing units. Each individual GPU processing unit is much smaller and simpler than a CPU, so that a large number can be packed on a chip, and the overall power and waste heat problems are manageable. As I say, it's a case of different things being specialized to do different tasks well.",
"CPUs are fantastic at what they do, but what they do isn't how graphics are processed the best. Basically, CPUs run at higher speeds with fewer cores, so that things which can't use multiple cores well go as fast as possible, which is most things. Graphics cards though, use the way that graphics are rendered to specialize. Every pixel on the screen is calculated nearly entirely independently from any others, so there are essentially hundreds of slower \"cores\" running at the same time running each pixel independently. They have immense power efficiency for the total number of calculations they do, but are terrible at doing a linear calculation quickly. You can actually run graphics on CPU, very easily in fact, but they can't do nearly as many things at the same time or match the same total speed. A top of the line modern CPU with 64 cores which costs $4000 or more can barely run Crysis at lowest settings, while my cheap GPU from 2013 can run it at max settings, simply because it does simpler calculations in parallel rather than complex ones sequentially."
],
"score": [
34,
18,
10,
7
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlb4lp
|
How do video game mods work?
|
How do you make them? Why can’t you use them on consoles like Xbox?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwxws7o"
],
"text": [
"You can't do mods on consoles because they require games to be digitally signed, and the file system is locked down, so there's no way to get mods files in there. Skyrim and Fallout 4 allow mods on PS4 and Xbox One by downloading them in game, and then the game puts the files in the correct spot. Mods work because games are designed to read files to know what need to be loaded next. If you know how to change existing files, or add in new files, then you can change what the game displays or does. Some games have built-in mod support. Bethesda Game Studios provides their creation kit to make modding their games very easy. They use a plug-in system that makes changes when a mod is loaded. There's no detection or protection against mods changing the same thing, so if you have multiple mods that change the same thing then the mods might not work or the game might crash."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hle3gx
|
How does 5G work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwygg3p",
"fwynfz7"
],
"text": [
"Alright, I don't get all the technicals, but the idea is that wireless signals are waves, with peaks and troughs. Currently, networks run on 2.4 gigahertz, I think. 5g uses waves on the 25ish gigahertz band. 5G stands for 5th gen, not 5 gigahertz. More gigahertz=faster wave, more peaks and troughs the wave moves per second. If you think of each peak as a one and each trough as a zero, it just has more zeros and ones per second, so it's faster. If someone has an engineering degree, please correct me if I'm wrong cause I want to learn more too.",
"Is OP talking about 5G as in 5 GHz waves, e.g. wifi, or 5G as in fifth generation of cellphone connectivity, i.e. being rolled out as we speak which people think caused COVID?"
],
"score": [
11,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlfysi
|
why does storage on games on disc for the ps4 have to be downloaded to the console and not be stored on the disc like say the ps2?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwysmxl"
],
"text": [
"Hard drives can typically access data much faster than a disk drive can read data off of a disk. With games becoming bigger and bigger files, the need for quick access to more info becomes more important."
],
"score": [
21
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlh1gn
|
What is the difference between RAM and storage?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwz05ez",
"fwzedhx"
],
"text": [
"Ram is like a piece of scratch paper you use to work out a problem and toss in the trash after use. Storage is like a tablet full of notes or information that you hold onto because you may need to reference it later. That was the ELI5 answer anyway. More technically, when a computer executes code, it needs a place to temporarily store values for executing processes. This information can be dumped after the process has be executed. That is what your RAM is for....temporary storage of data for computing. Storage, on the other hand contains data that you want to hold onto indefinitely. Things like images, documents, videos, and even the code of the programs themselves.",
"You’re in a library. The storage are the bookshelves which hold all your files and apps. The RAM is the table where you sit, in which you spread the documents and apps you are working with. Having enough RAM is important as you need enough table surface for everything you want to keep opened at the same time. If you have a small table and run out of space, opening a new file will mean removing from the table other file you had opened to make space for the new one. If, then, you want to use that file, you’ll need to go get it again from storage (bookshelves), which is way slower. Therefore being low on RAM impacts performance. A lot. Having more or less storage does not impact performance. It’s just about keeping more stuff. Hope it helps!"
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hli8gp
|
How do emulators save games?
|
OK bear with me here, I suck at computers. How do emulators save my game? Where is the saved data stored? Let's say I want to move my data of gameX to another laptop. Is there a file I can shove in a hard drive, plug into laptop 2, and continue where I left off? Also, after dragging the downloaded game into the application, it runs like magic. If I were to delete the game from my folder, will it get deleted from the application as well? Sorry for the question spam, but I never really got this, and the paranoia of suddenly losing my saved games is eating into me.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwz7opt"
],
"text": [
"Emulators in addition to emulating the hardware can also emulate however the original game system saves data. SNES emulators where the save data is on the cartridge will typically store save data as a separate file in the same folder and with the same name as the ROM but with a different file extension. Save states where you can save at any point are done by saving the entire state of any memory that the hardware has. Things like the state of CPU registers, and RAM contents, and saves this in a format specific to the emulator in a file. As to where these files are, it depends on the emulator, and you'll have to look for the specific folder on the emulators website or Google. Places it could be are usually the same folder the ROM is in, in %AppData% on Windows, or in a folder where the emulator is installed. But yes, after you figure out where the files are you can back them up to an external drive. Oh right, dragging the ROM onto the emulator shortcut is just a common shortcut that opens the emulator and tells it the location of the ROM at the same time. Or dragging it into the open application is a similar shortcut that opens the rom. Nothing is actually copied (usually), so don't delete the ROM."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hlljyx
|
How does my phone recognize all of the different WIFI’s around me?
|
Though I get how routers work, how they send out/receive data as a wave signal, I’d love to know the process behind it. The question is, how does my phone recognize all of the different wifi’s sending signal on the same frequency? Is it the packets? headers of packets? or rather some sort of ID signal that it sends out ? Thanks in Advance!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwzup1w"
],
"text": [
"The explain like I'm five answer: Your device sends out a request on the WiFi signal saying hey, what's out there? The device says hey, I'm here. Wanna connect to me? Your device says hey I see you, yeah I want to connect, here's the password. All of this is possible because they're in the same room ( WiFi frequency) and using the same language (protocol). The answer, to the level of detail I think you want, is a little more complicated. Internet devices send different types of traffic out using different languages, those protocols I mentioned earlier. Which protocol you use, what information gets added, where it gets added, how it gets added, is determined by what \"level\" of communication you are working at in the OSI model (more on that later). As the information goes out from the device at different levels, additional information is added to it so it can be handled properly. Kind of like when you send a letter. The letter is the data being send, but you have to put the letter in an envelope, then put the envelope in a truck, etc. Until it makes it to it's ultimate destination in someone else's hand for them to read. This process is called encapsulation. [ URL_2 ]( URL_0 ) & #x200B; Now I'm a little rusty since I did my Network+ quite some time ago, so Redditors feel free to correct me, but the type of network traffic you're talking about generally happens at the Network layer, or level 3 of the model. So when that data (or frame) you want to send gets ready to leave your phone, your phone will add a bunch of routing information to that frame and turn it into a packet, again based on the protocol(s) you want to send it out on. There's a LOT of protocols that deal with routing, but the Wiki page for the OSI model is a good starting point to break things down. [ URL_1 ]( URL_3 )"
],
"score": [
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Encapsulation_(networking)",
"https://en.wikipedia.org/wiki/OSI\\_model",
"https://en.wikipedia.org/wiki/Encapsulation\\_(networking)",
"https://en.wikipedia.org/wiki/OSI_model"
]
]
}
|
[
"url"
] |
[
"url"
] |
hlmhhy
|
Why is a company like Intel with 4th highest R & D budget not being able to compete with ARM? Will they really "die" once ARM based chips become powerful enough for server use?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fwzv2jd",
"fwzz183",
"fx01yus"
],
"text": [
"it's not that they aren't able to compete with ARM. it's just that big enough companies like amazon/apple maybe even facebook would rather control their entire ecosystem entirely and bring in in house design to customize for their specific purposes and use cases. for the vast majority of companies that aren't amazon/apple or maybe even facebook, they will just continue to purchase from someone, probably intel or amd. since amd/intel is unlikely to license out x86, amazon/apple/etc has only ARM to turn to.",
"ARM doesn't build chips - it just designs them and licenses the design to other companies to actually build. This means that ARM doesn't have to spend billions of dollars to build and maintain chip factories, and all of the employees those require. It doesn't have to spend billions to upgrade those factories for the next generation manufacturing process. So ARM is already ahead in having a LOT fewer expenses than Intel. ARM is also more nimble, because it can make changes to its designs without worrying (as much) about how it will impact manufacturing and all of those expensive factories. So ARM has some built in advantages that can't be overcome by just spending on R & D. & #x200B; > Why are companies like AMD and Intel not bothered at all by such developments? Why do you think this? I'm sure they are bothered a LOT by this. They probably don't issue press releases saying \"fuck, we're screwed\" but I bet they do spend a huge amount of time and money trying to address this problem.",
"Intel does more than manufacture desktop and server CPU’s. When you see Intel’s R & D budget you’re seeing investment into other areas not just server CPU’s. Apple has no intention of competing in the server space. ARM processors are designed to be as simple to keep energy waste to a minimum which would not be a good fit for server requirements. As an example of Intel’s diverse portfolio, Apple recently bought Intels smartphone modem business which was an outcome from the R & D investments. URL_0"
],
"score": [
8,
4,
3
],
"text_urls": [
[],
[],
[
"https://www.theverge.com/2019/7/25/8909671/apple-intel-5g-smartphone-modems-acquisition"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlojpr
|
Why are apps so much better quality at calling and texting than the calling and texting built into the phone?
|
Isn't the whole point of a phone the calling and texting But things like Instagram dm are just faster and images go through at higher quality but it's just an app.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx0euvb"
],
"text": [
"Companies have two options when it comes to deploying their innovations. They can either deploy them in their walled garden apps using proprietary protocols or they can work together with other companies and create standards such as SMS. These companies chose to do the former so that's why their apps are better than the standards. It's also why IRC has fallen behind chatting apps."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hlowdv
|
Why do extended displays for computers require display port wires? Why not have them all regular HDMI?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx0cr2g",
"fx0lafi",
"fx0cs9n",
"fx12t64",
"fx2bjje"
],
"text": [
"Equipment manufacturers have to pay royalty fees to include HDMI ports in their equipment. Displayport has no such fees so they often use Diapkayport to save money. URL_0",
"Display port cables are able to send more video data each second than HDMI. So displaying a higher resolution at a high refresh rate will generally require display port",
"What exactly do you mean by \"extended displays\"? If it the multi-screen support in windows then there is no requirement for display port. I have run multiple screens with 2 on vga and 1 on DVI It might be required because of the ports your graphics card has. Many display port connections on a graphics cards can also output HDMI so only a passive converter is needed or a cable wit different connectors in each end. DisplayPort was developed as a replacement the VGA and DVI that was common back then so you can send the video, audio, USB, and more data over a single cable. The data on it is a lot higher than HDMI so it supports larger screen and higher refresh rate and I suppose this is the main reason it is common on the graphic card today",
"DisplayPort is preferred for a few reasons. 1. As another comment says, DP doesn't have royalty fees associated with it, but that's not the primary reason, especially for gaming. 2. You can daisy-chain DP, meaning you can run multiple displays from one port, which is handy for a lot of use cases. 3. With gaming monitors, DP allows adaptive sync where HDMI doesn't (at least, not to my knowledge). Adaptive sync (Freesync, G-Sync etc.) allows the monitor and GPU to communicate and time frame rendering with display frequency, provided both are compatible. Say you have a 60Hz monitor; that means your display is capable of rendering a complete screen refresh (redrawing everything on the screen) 60 times per second. Your GPU on the other hand may be capable of pushing 144fps. What happens then is that by the time the monitor is a little under halfway done refreshing the screen, the frames coming from the GPU have advanced, and now everything is in a slightly different spot than it was when the screen was first being drawn. This creates the effect known as \"screen tearing,\" and it's ugly. It also leads to dropped frames (frames that just aren't rendered at all as the display and GPU catch up with each other) which looks jerky and weird. But with adaptive syncing, the GPU and monitor agree on how many frames it's OK to draw at what rate--among other things--which cuts down on these effects considerably.",
"Each standard was originally designed for a different use-case. HDMI was originally designed for TVs. The specification is controlled by a bunch of companies that work in the TV space. It has features intended for TVs (such as HDMI-CEC, ARC, and support for TV resolutions and refresh rates). It does not have features intended for PCs - or where it does, they were added recently and are not widely supported. E.g. support for resolutions greater than 720p/1080i was not originally included because TVs did not support it, then they added 1080p when TVs started adding support, then they added 4K when TVs added support for that. DisplayPort was designed for PCs. The specification is controlled by a bunch of companies that work in the PC display space. It has features intended for PCs (such as support for PC resolutions and refresh rates, daisy-chaining, and USB). It does not have features intended for TVs - or where it does, they were added recently and are not widely supported. E.g it doesn't support HDMI-CEC or ARC. Nowadays, there are a lot of TVs, DVDs, etc that use HDMI, so changing TVs from HDMI to DisplayPort won't happen. And there are a lot of PCs and monitors that use DisplayPort, so changing PCs from DisplayPort to HDMI won't happen either."
],
"score": [
138,
36,
21,
9,
5
],
"text_urls": [
[
"https://www.semiconductorstore.com/blog/2014/licensing-costs-HDMI/654/"
],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlrwcu
|
What is the relationship between bit rate and resolution?
|
How would a low bit rate video still retain the 1920x1080 if the video quality suffers? Isn't resolution the amount of pixels (width x height)? And don't the amount of pixels reflect quality (4k resolution better quality than 2k resolution)? So what does bitrate have to do with the drop in quality? thank you! EDIT: Does the bitrate tell the video player (or whatever is 'decoding' the file) what to play? Is that how the video quality drops, because it's being told to not look at the resolution but instead the bitrate itself?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx0vsvs"
],
"text": [
"Video is typically served compressed. There are two types of compression algorithms, lossless and lossy. Lossless compression, as its name suggests, is completely reversible. You can get the original back exactly as it is. Lossy compression on the other hand gets you back something close enough to the original that most people wouldn't notice. This also means you can dial lossy compression up and down, choosing how much detail to keep, but at what cost in size. Video uses lossy compression. When it has a lower bitrate, that dial for how much detail to keep is cranked down. When it's a higher bitrate, it gets cranked up. You still have the same number of lines drawn, but the amount of detail in those lines changes."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hlsif6
|
What is Tor/onion? I don't know anything about the computer world but I am willing to learn.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx0z5cm",
"fx0zgvu",
"fx16fgf"
],
"text": [
"When you browse the internet things like your IP address can be tracked. Your public ip can be used to determine your location and your name (or at least your account holders name) This is bad for lots of reasons but a common one is if you live in an authoritarian government they can see if you go to a no no site and punish you for it. Tor and onion are ways to hide your ip. Simple analogy - if you call my cell from your phone. I can see your number and based on area code I can glean a lot about who you are and where you are. But what if you called an anonymous 3rd party and had them call me on your behalf. Now I have someone else’s information and it’s harder to trace it back to the original source. Tor/onion does this on a mass scale",
"tor is an acronym for “the onion router”. Normally when you visit a website let’s say google, your pc tries to create a “direct connection” to the google server. In this case google can gather some information about you such as your approximate location. In contrast the tor network uses other computers in the tor network to bounce your request to google. As opposed to the normal direct connection where you’d just connect to the google server, when using the tor network your request goes through Alice’s computer and then through Larry’s and then John’s and so on, essentially covering your trail, as whatever details google can read would be irrelevant as it might belong to anyone your request bounced through. Most of the use cases for Tor are illegal activities given the privacy of it all, but it has some very important and positive use cases like newspapers drop boxes (where you want to report something truly anonymously) or the military.",
"Onion routing is a way to hide the origin of a message online. The way it works is that an encrypted message is passed around from one person to another in a network of people. In this process, layers of encryption are peeled off one by one like the layers of an onion. Under each layer are hidden the instructions on how to peel off the next layer and who to send the onion to. Instead of simply peeling off all the layers in one go, each participant in the network peels off one layer and sends the onion to the next recepient. Finally, when all layers have been peeled, the last member in the chain sends the unencrypted message to its actual recipient. As the members in the chain of passing the onion around have no way of knowing how many layers are left in the onion or how many layers have already been peeled off, the original sender of a message can hide the fact that they created it by simply claiming that they got it from someone else and that some layers had already been peeled off the onion."
],
"score": [
4,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlsj6g
|
How does a GPS calculate remaining time on a road trip?
|
I just drove almost seven hours from Virginia to New York. I usually do 10-15 over the speed limit on road trips, so I ultimately end up arriving before the ETA that is listed at the start of the trip. My question is, does the GPS recognize that I’m consistently driving above the posted limit and factor that into the ETA, or does it assume I will drive the speed limit the rest of the way and then continue recalculating ETA throughout the trip?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx0ypsf"
],
"text": [
"Your hunch is bang-on. The GPS knows your speed and the remaining distance, so it simply calculates the remaining time"
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hlvn96
|
Why can taskmanager close my running programs when I'm not able to close them manually?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx1j8lz",
"fx1of6e",
"fx1k5yc"
],
"text": [
"Closing the window from within the running process is trying to call a function of the running process whereas stopping it from task manager uses an operating system call to kill the process instead of the process trying to close itself. I hope that makes sense.",
"Closing a program is like telling someone it's time for them to leave your house. If they're cooperating then they'll get their coat and shoes, take anything that's theirs, say bye, and leave. A crashed program is like that person just sitting on your couch and ignoring you. You can *tell* them to leave all you want, but they're still just gonna sit there. Closing a program from the task manager is like *throwing* them out of your house. Mission accomplished and they're gone, but they might have left some of their stuff laying around. Anything left behind will just be clutter until the next time you clean the house up (== reboot).",
"There are different ways to close a program. I'm not too familiar with the inner workings of Windows, but I'll explain it in Linux, I assume Windows uses a similar concept. If you click the \"X\", you basically ask the program \"I want to quit, please clean up after yourself and then exit\". In Linux, this is done by sending SIGINT or SIGTERM signals. If the program is stuck, it might be unable to do whatever it's supposed to do after getting a signal. You can however also just boot the process off your system by sending SIGKILL. This doesn't require the program to do stuff on its own, but it's also dangerous since it can't clean up, e.g. save open files."
],
"score": [
72,
59,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hlxwtc
|
How does a scale calculate your Body Fat, Muscle Mass, BMI and etc.... when you’re weighing yourself?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx20b56"
],
"text": [
"For BMI you would have to tell it your height as BMI is just a \"score\" based on your height and weight. For body fat/ muscle mass the scale can run a current through your body to measure your body's electrical resistance as fat and muscle have different ratios between mass and resistance."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm0f2p
|
How do smart watches know when you are sleeping and how much time you spend on the different stages of sleeping?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx3n3gd",
"fx313k1"
],
"text": [
"Just to add on to other comments, smart watches really *can't* determine which stage of sleep you're in. While it's possible to make educated guesses based on movement and heart rate (which is, in fact, what sleep tracking apps do), those sensors alone are not sufficient to confidently discern between them.",
"It depends a lot on what watch and how sophisticated it is, but it's a lot of software magic. Like my watch can track blood oxygen saturation and pulse with it's heart rate sensor. Looking at variation in heart rate it's possible to figure out when you're taking a breath. It will take all that plus the accelerometer, which can sense your movements, to guess at what stage of sleep you're in. It's a lot of guess work and software magic that makes the graph actually look good. It will assume things like if you're in deep sleep you won't just go straight to rem sleep for a short moment then back to deep sleep. If it thinks you're pulse is 52 bpm, it assumes your heart won't just stop beating and suddenly you're at 0 bpm, likewise you suddenly won't just jump to 190 bpm. If I just take off my watch right now instead of going from 64 bpm to blank straight away, it will start panicking and show like \"64 bpm, 67 bpm, 73 bpm, 79 bpm, --, -- \". If you're a normal human being it will probably be relatively accurate since that's what it's biased for. Say your resting heart was 750 bpm and you're like a hummingbird or something, the watch would have a very difficult time ever telling your pulse."
],
"score": [
5,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm0vec
|
If you need programs to program programs, then how do you program programs that are used to program programs?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx2i1mk"
],
"text": [
"You don't *necessarily* need programs to program programs. In fact, there's a term in programming, called *bootstrapping,* where programmers carefully program a very simple program manually, without using other programs to program the program, and then use that program to program more and more complicated programs. (Albany bison can intimidate Buffalo kine, too.)"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm4lk9
|
How is polyphonic music encoded and read in the grooves of a vinyl LP?
|
I can roughly imagine how a single melody can be encoded and read from the grooves of a plate but I am completely at a loss how this works with more complex musical plays.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx328uo",
"fx32jjp",
"fx32ofw"
],
"text": [
"Polyphony as a concept doesn't exist in records, it only exists in sheet music or equivalent human-readable forms. The record doesn't know that there are multiple instruments playing, it just saves the resulting sound wave. When you listen to it, your brain decodes the sound wave into multiple melodies or instruments.",
"The same way it's \"encoded\" in air when we hear the music live. Air molecules don't split into which ones will do the strings and which will be the brass section. When the air vibration reaches our ears, every molecule is doing every instrument at once. Then we, in our heads, pull it back apart — based on our knowledge of what instruments sound like, and our general ability to spot patterns.",
"What is encoded in the groove is not the music as played by instruments but the resulting soundwaves. If two different sound source are audible at the same time, the waves they create overlap and create a new more complicated wave. The back and forth of the groove just follows the back and forth of the air. It is only in your ear and brain where that gets separated again into different components, it doesn't exist as separated phenomena in the air or on the record."
],
"score": [
8,
5,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hm4lxh
|
Why is there always huge graphical differences in gaming console generations yet PC games are only slightly better than their counter parts instead of leaps ahead?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx32akq",
"fx3e3fh",
"fx38ub5"
],
"text": [
"Much more optimizations on consoles? Id say that it is the main reason. Some games proved that, if they're optimized on pc too, you can clearly outperform the performances and graphics that you get on a console. But it takes much more time to get it right for every single graphic card driver, for instance, than a single console",
"Many factors here. PC exclusives typically do feature graphics that are miles ahead of their console temporaries, famously you have Crysis, which after cutting down the graphics, the consoles still struggled to run at even 30FPS. Non-PC exclusives mostly have PC as an afterthought, which is why many \"Ultra\" settings featured mostly shadow/lighting improvements and nothing else. Note that this is not always the case, some console-ported-to-PC games are well ported with huge graphical improvements. People need to realize that AAA gamedevs cater to the most common denominator since the *very beginning* of the game's lifetime, so it's really hard for a PC game to be vastly superior to its console counterparts unless the dev deliberately spend time doing so. I'm personally a PC gamer, but honestly I didn't buy my PC for purely games, I am also using it to do my work etc. Whereas if I'm buying a console it's definitely going to be a gaming machine as I don't watch much TV. So I guess there's a \"features per buck\" factor for my case.",
"On PC, there used to be a new generation of hardware every 1 to 2 years. But there's a lot more time between console generations, so they catch up in 7 or 8 years or so. So if you look at different PC games that are further apart, there are also often huge leaps. Take for example Half-Life (1999) and Half-Life 2 (2004), or Far Cry (2004) and Crysis (2007). However, we don't often see such big leaps any more because there is a law of diminishing returns. What that means is: the more developers improve graphics, the more difficult it becomes to find more ways to improve further. So for developers, there's not that much focus on pushing the optics of their games to the limits of high-end gaming PCs, like the developers of Crysis did. Instead, they try to make them run on cheaper and older computers. Games released today run just fine on a mid range gaming PC from 5 years ago, which would have been unthinkable back then. The same will happen with consoles. Microsoft already announced that their exclusive games will also run on the older systems."
],
"score": [
9,
3,
3
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
|
hm4yef
|
If all phone numbers start with an “0” (at least they do here in the UK), why not just drop the “0” and make the numbers shorter/easier to remember?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx33wdn",
"fx35e01",
"fx35wnt"
],
"text": [
"The 0 is a shortcut for +44, which is the international phone code of the UK Without +44 (or 0 which defaults back to it) you could run into trouble where a number could be ambiguously interpreted as either a local phone number or an international one",
"For landlines with a geographic area code, you can (or at least could until recently, not sure if it’s changed ) omit the trunk prefix and area code to dial other number in the same area: eg dialing 12345678 in London tries to contact 020-1234567.",
"As far as I can tell, the 0 at the start signifys that it's a domestic-to-domestic call, you could use the +44 instead, but it's not necessary if it's domestic-to-domestic. If, for example, you call a Spanish number from a UK mobile in the UK you would have to add the Spanish country code (+34) to replace the zero because it's an international call, it informs the UK network as to where to place the call. I work in telecoms, not a networking expert though"
],
"score": [
11,
7,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm53lx
|
How come one can watch HD live streams but video calls are low quality
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx35nlu"
],
"text": [
"Another issue is latency. A high-quality livestream has significant latency from the streamer to the viewer (several seconds). Video calls can't afford to have that kind of latency. Its a smaller time frame to process the image (capture, encode, send over, decode). So the image quality has to be lower."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm5np8
|
Why do movies not allow to adjust the volume of effects, music, and voices, while video games have been doing it for years?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx37yg3"
],
"text": [
"These can make or break the atmosphere of a movie. Therefore, mixing is done by a professional and encoded in a way it can be accurately reproduced in a theater or your home. At home you can change frequencies or volume of different channels, but the mixing is going to be static."
],
"score": [
19
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm681p
|
I see people taking weeks to make a simple thing in Blender so how on Earth do game developers create so many unique assets in just a few years?!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx3acor",
"fx3bb8f"
],
"text": [
"1: they have massive teams, just look at how large the credits are for games like that. 2: they are the best at what they do. They do it for a living, 8-12 hours a day, 5-6 days a week. They develop shortcuts, sixth senses and instincts over time. 3: they start from old assets and improve upon them quite often, not from scratch.",
"In addition to the other answers, there's also procedural generation. For example in Eilte:Dangerous, the designers don't hand-craft every planet. They write a set of rules for the computer to generate them and just tweak some of the results to fit specific gameplay purposes."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm84nx
|
How speakers work
|
As far as I am concerned speakers have always been magic sound boxes. What are the basic principles that allow us to produce sound using these devices?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx3m19b",
"fx3raau"
],
"text": [
"Sound is created by vibrating air. Speakers use a flat disk connected to an electro magnet to cause that vibration. [example]( URL_0 )",
"If you've got some time and interest, [this video series]( URL_0 ) goes into extreme depth on the history and mechanics of artifical sound. The first video explains speaker diaphragms and how sound works in general."
],
"score": [
5,
3
],
"text_urls": [
[
"https://animagraffs.com/wp-content/uploads/loudspeaker/loudspeaker.gif"
],
[
"https://www.youtube.com/watch?v=NsdHAXTaQc0&list=PLv0jwu7G_DFUYPuDoKWCUy33lL9LnMBGX"
]
]
}
|
[
"url"
] |
[
"url"
] |
hm8fyd
|
Why does old music sound like old music? (50s music, for instance)
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx3nfe6"
],
"text": [
"Some of it is related to the trends of music and how they evolve over time. Another interesting factor is recording technology has changed significantly since then, so old recordings sound old no matter what."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hm8jfh
|
What causes one device to have a better connection than another device?
|
I got a new phone this week, and while I was attempting to watch a twitch stream at breakfast, it kept stuttering. I haven't had this problem before I thought, so I got my old phone, and sure enough, my old phone could watch the same stream in the same spot at 480p, while the new phone was in a constant stuttering at 360p. What causes one device to have a stronger connection than the other, and is there any way to "fix" it?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx3um54"
],
"text": [
"There are a lot of variables that play into this. 1. Antenna design in the device 2. Firmware of the wireless radio 3. Frequency that the radio is communicating on You may want to look if the old phone only supports 2.4GHz if it does it may be connecting on that frequency and the new device may be connecting on 5GHz."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hmbwbk
|
How do RGB lights work? Like light bulbs use a colored glass to make the color different.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx49pwd",
"fx49br0"
],
"text": [
"No, they aren't coloured glass. LEDs inherently release light of a single colour. A red LED is actually red. A green LED is actually green. There is no filtering glass. A white LED doesn't actually exist. A white LED light is a blue LED with a coating of phosphors that absorb some of the blue and release reds and greens. Still not the same thing as a coloured glass filter. RBG lights have red, green, blue LEDs. Most colours can be made from a combination of those three. Yellow for example works from green and red in combination. It looks the same to your eyes as true yellow light (say in a rainbow).",
"RGB lights typically have 3 or 4 LEDs (Light Emitting Diodes) in them; a red, a blue, a green, and sometimes a white one. By varying the brightness of each LED, you can get any colour you want."
],
"score": [
6,
3
],
"text_urls": [
[],
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}
|
[
"url"
] |
[
"url"
] |
|
hmgx24
|
How do radio waves work? Are some stronger than others to get signal?
|
I ask this because today sitting in my old car with a non DAB radio, I could listen to French Radio KHZ 234 AM in the Midlands, UK and have no idea how it can reach that far!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx55iaa"
],
"text": [
"Well! The theory and applications of radio waves is extremely vast and often complex (*pun intended for those who get it*). Radio waves are just a subsection of the general electromagnetic waves. In nature there are two fundamental fields called **Electric field** and **Magnetic field** which are at the base of all electro-magnetic fenomena. A set of equations called **Maxwell’s equations** describes how these fields can ripple and propagate through space, creating what we call electromagnetic waves. Radios use those waves to transmit and receive information. As you supposed yes, the frequency plays a role in how well the wave is transmitted through space, and higher wavelengths (which means lower frequencies) are able to better convey the transmitted power to the receiver. Moreover, the modulation (AM vs FM) also plays a role, since AM can travel further than FM — at the cost of lower transmission quality."
],
"score": [
11
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
hmhi4j
|
Why do blacksmiths need to 'hammer' blades into their shape? Why can't they just pour the molten metal into a cast and have it cool and solidify into a blade-shaped piece of metal?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"For an analogy (obviously not a perfect one), think about pizza dough. Why not just mix the flour and water together a little bit and pour it onto a pizza-sized platter? Why spend all that effort kneading it and stretching it out? Because kneading and stretching the dough changes the form of the gluten molecules, making them all stretchy. It gives the pizza crust that nice chewy texture.",
"Cast metal is strong thick. Like a cast iron block in your classic car. Forged metal realigns molecules to be stronger thin, but is more labor intensive.",
"Then it would be cast rather than forged. Forged metal is stronger than cast metal. Forged metal has a kind of grain. It’s like the difference between hitting someone with a piece of MDF or a similarity dense 2x4. The MDF is gonna break a lot easier because it’s just a bunch of particles pressed together rather than oriented and interlocked with a grain.",
"Bronze blades were in fact made that way. Then simply needed cleaning up after being cast. Iron and steel don’t have good metallurgical properties when cast, though. They go through molecular changes when forged that give them the combination of hardness and springiness needed to be a good blade.",
"Some of the answers here are close but none are completely correct. Metals are crystalline meaning all the atoms are arranged and spaced in a predictable ordered array. In a perfect theoretical crystal, every single atom would line up perfectly with the next, however in this is not usually the case in most pieces of metal, and would actually make the metal weaker. When all the planes of atoms line up perfectly, it makes it easier for them to slide past each other when the metal is under stress, effectively allowing the metal to deform. But if you have smaller crystalline regions in the metal that are misaligned with each other, the atoms can't slide past each other and lock up at the regions in between these small crystals, known as grain boundaries, preventing further deformation. When a blacksmith beats a red hot piece of metal, they continuously fold and flatten the piece of metal, refining the small crystalline grains in the material, making them smaller and stronger, so there is a higher chance that they will lock up if the metal is stressed. A cast or melted piece of metal has larger grains than a hammered piece of metal, as the atoms have time to organize their structure as it cools, which weakens it significantly. If you've ever seen a galvanized metal street pole or roadside barrier you can actually see the individual grains on the surface as they are very large. Most swords would probably have grains under 1 millimeter across, probably smaller. If you want more info on this look into grain boundary strengthening. Source: am PhD student in metallurgy",
"Because forging realigns the metals structure, making it tougher and more resistant to breaking. A cast knife would be so brittle as to be useless, I think., but this being Reddit, I am certain there is someone who knows much more than I do!",
"There’s a few reasons why forging works better - casting is done at much higher temperatures than forging - you need a mould that can handle molten steel (not impossible, but not easy either) - the forging process helps drive out impurities in the material leading to a better quality steel with the technology available at the time. - casting steel and irons tends to lead to higher carbon alloys which are more brittle With modern materials technology, the most efficient way to make a good steel blade is often a blade shape from flat bar of the right thickness and then grind out the shape being careful not to overheat the blade then heat treat it. It’s a lot easier now though as I can just order a specific alloy with the right components in a consistent distribution and structure. They had to deal with whatever came out of the local smelters which was highly dependent on local ores. This is also one of the reasons why swords or armour from specific areas were better than others",
"> Why can't they just pour the molten metal into a cast There's no \"just\" doing anything with molten steel. It takes crazy-hot temperatures to melt iron. Forging, on the other hand– where you heat iron or steel to soften it, then press or hammer it into shape– needs much lower temperatures. Anyway, modern knives are often made by stamping out the rough shape of the blade from bars of metal and grinding them down to an edge. It's faster, cheaper, and can get better results\\* than forging.",
"Lots of missinformation here. Forging is ultimately much more efficient than casting thin pieces. It's much cheaper to hear a forge, than a kiln. Failure rates of casting thin pieces is higher than forging them. You can't fix a bad cast, but you can fix a blade being forced as you go along. Everytime you heat metal above a certain degree it starts to oxidize and wasted, when it's melted it's called slag. More waste is produced with melting than with hearing to forging temps. Short answer, higher rate of success and it's cheaper.",
"Casting blades into the shape first without hammering them is actually one method that is used in forging blades. You just get some EXTREMELY compact sand and press out a mold you want to fill, and fill it with molten metal. I believe this is a Bronze Age method and there are different benefits to different methods. Ultimately, casting into a mold is not very reliable - you wont know that the full mold is filled until you take the mold apart, or that the sand was compact enough to hold the liquid metal in place, molds only usually last one or two uses, and the length of the blade is limited by your ability to make certain lengths of molds reliably. There is really just much more precision and variety available in the using a blacksmithing hammer.",
"It has to do with the molecular structure. Temperature will determine the phase, and cooling will determine how the phase is locked and aligned. Hammering also allows for multiple phased metals to be put together to get better overall blade properties so it can flex where it needs to and be harder in other locations. Here's a chart to give you a glimpse of metallurgy phase structure. URL_0",
"Hammering out the metal breaks up the dislocations & helps distribute them out so that the blade can maintain its strength & some elasticity. The dislocations will keep a grain boundary crack from propagating throughout the blade. Casting would lead to a strong metal, but not as strong as forged & much more likely to fracture under impact.",
"One important difference, you can't cast steel if it has to be strong , because it gets so hot the carbon stops being incorporated in the steel and it turns brittle this is because it got melted once when it was turned into steel and bringing it to that point again stresses the \"new\" metal. Each metal has a certain grain because of the molecule/s that the metal/alloy is comprised of reacts differently to everything (typically within seemably reasonable norms (Sodium is a metal))",
"Everyone is going into crystal structure, which is not really what stops blacksmiths from casting iron or steel. The main roadblock is just that it's really fucking hard to cast iron. The melting point is extremely high, (I've only successfully melted it once, and that was using coal, an electric blower, and modern refractory insulation) and before the advent of modern refractory materials, it would have been nearly impossible to work with. Even today, it is many times easier to just work a pre-cast piece of steel into the shape you want than to heat it up past 1500°C and re-cast it.",
"There's many reasons why we forge instead of cast things: - When you cast something you can form little bubbles and voids inside your metal, because most metals contract when they solidify. These can start cracks. By forging the material after casting you can squeeze these bubbles shut. - Forging can squeeze out impurities, basically like dirt, in your metal. There are ways of removing impurities from liquid metal, but you need more technology, especially for steel and iron, so for those metals forging helped to clean them up. - Metals are like Styrofoam, they're made up of lots of little particles (grains, or crystals) stuck together super tightly (little to no space between the particles). Counter-intuitively, metals with small particle sizes are much stronger. Casting tends to give you big particles which are long and thin. Forging breaks up those big particles, makes them much smaller and makes them more uniform in size.",
"Not all iron alloys are castable with pre-modern technology. Pre-modern technology only allowed to cast pig iron, a.k.a. cast iron, which is very rich in carbon, hard and brittle. Resilient and springy steel could not be melted in primitive ovens, it could only be softened. So they softened it and hammered it into shapes.",
"when you heat metal up the particles expand and leave gaps, so the hammering puts them closer together, and then the blade is quenched, which makes the particles stay in that position which should, if done right, make the blade strong",
"ELI5: Forging (hammering/rolling semi-molten metal results in stronger materials than casting (pouring into mold). ELI-Smart: Metals, and many other materials, have imperfections known as grain boundaries. These grain boundaries represent high angle microscopic fractures that weaken the metal. When a blacksmith hammers the metal, it strain hardens the metal. This means that the grain boundaries pile up and begin to run into each other. The result is that the fractures interact at lower angles. This makes a stiffer, stronger blade, but the lack of flexibility comes with an increase in risk of brittle fracture. Try to turn a screw with your 440c stainless steel pocket knife and the tip may hold up, but do the same with your super-hard sharp-forever exotic alloy $250 pocket knife and you may be sad and out a bunch of money when it snaps. ELI-Caveman: Me smashum hammer. Arrrghhhhhh! Cut good. Break bad! Arrrhhhghh!",
"Bronze swords were typically made just that way: melted and poured into a mold. But bronze has a low melting point for a metal alloy, which is why it was the first tool metal used by ancient civilizations. Steel is much harder and has a much higher melting point, so its much much harder to melt and cast. Possible, but extremely hard. But that's not the reason why steel weapons and tools are forged instead of casted. Casted swords would be soft and bend easily: when you melt metal the molecules become loose and flowy, and they solidify in a relaxed state. The same is true for steel even if you heat it up without melting it. Forging the steel after its molecules are \"loose\" like this does something called \"work hardening\" which squishes the metal flat and brings the molecules closer together, allowing for less wiggle room and thus making it harder. Think rolling up a tin foil ball. Tool steel must be extremely hard to resist constant wear, and the best way to do that is to forge it, then heat the finished piece and quench it; this shocks the metal by contracting very fast and makes it even harder. Then you temper it, which makes it a little softer so it gives instead of being brittle and snapping, which you don't want.",
"The metal would be very brittle and snap easily, by heating and hammering the metal (folding) as well as laminating (layers of other metals/materials) you can increase it's flexibility while keeping it's hardness. Kitchen knives are a great example of this, to cut through normal every day items (say raw chicken or onions), you would use a chefs knife, large-ish multi purpose knife that is strong but a little bit flexible, when cutting joints or dismembering carcasses, you would use a boning knife, generally shorter than cooks knives, thicker and not really flexible, as you would use the knife to pry apart bones so you could cut the tendons, a flexible knife would just break. Then you have a filleting knife, usually about the same length as the boning knife, but about 1/3 as thick. This knife is very flexible so it can follow the contour of smaller delicate bones of, for example, a fish, allowing you to use little pressure so you do not damage the delicate flesh, but offering great precision and flexibility to do the job with 1 easy effortless stroke. When you heat the metal/s, you are weakening the bonds turning it from a solid to almost a liquid state, the hammering allows you to align the bonds how you need them (with a lot of practice and a damn good teacher), forming softer bonds for sharper edges, and harder bonds for blunt instruments. Really, all you need to know is that heating and tempering the metal make for a higher quality end product."
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|
[
"url"
] |
[
"url"
] |
|
hmidgw
|
Why people from different nations have different food staples?
|
Like in Asia people use rice as the food staple, while in Europe it is potato or bread, and in Middle East and India it is rice or bread
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx5dobd",
"fx5eh6j"
],
"text": [
"Different grains/crops grow better in different environments. So rice isn't a staple in Europe because it isn't the best place for it to grow, and so isn't a native crop there. Staple foods will always be what is cheapest and easiest to grow in that place.",
"Each region has different environments that can cultivate their staple crops well. Each of these staple crops are also native to these regions, long before human intervention and trading, so once humans began harvesting these plants and selectively breeding them, they became dépendant upon these crops as a main food source, where they ultimately became a big part of that regions culture. Different nations have different food staples because back when all of these areas had separate human populations developing indépendant of one another, they each had access to a specific crop or two that was good for mass food production in their region. Today we can trade and grow crops in other environments, but these areas still have the same staple foods partially because they’ve become a part of their culture and they just work pretty well as a staple food."
],
"score": [
13,
5
],
"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
hmk464
|
How does a MIG welder work?
|
My son is 4 and has an abundance of questions about the world, this is one he asks regularly because I don’t have an answer for it.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx5nid3"
],
"text": [
"A MIG (Metal Inert Gas \\[It won't react with the metal\\]) welder is an arc welder that uses high voltage electricity to generate heat and melt the feeder wire to the base material. You have a grounding cable attached to your work station and as welder pulls the trigger the wire is pushed through the nozzle completing the arc and the resulting electricity (depending on the voltage and heat settings for various metals and thicknesses) melts the base metal and the feeder wire to create a weld. If your voltage is too low the resulting arc does not generate enough heat to melt the base metal. If the voltage is too high it just melts complete through it resulting in a hole in your base metal."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hml5yi
|
How come when you download software do you have to approve the storage it takes up and install further? Shouldn't it already take up that amount if it's on your computer?
|
thanks\~
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx5uff5"
],
"text": [
"when you buy an item from ikea. shouldn't it only take as much space as the box when you're assembling it? because it's already in your house isn't it? same concept. you download the installer which is compressed data aka the ikea box. then you have to decompress the data, aka take all the pieces out of the box which takes up more room. then you have to actually install the program aka now you assemble the ikea item which takes up even more room. and then once the program is done installed aka you're done putting the furniture together. you can delete everything aka throw again the box and packaging and stuff and get all the space that you used up back. so if you have only enough room for just the box from ikea, good luck assembling it."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hmm8qk
|
How is that we can explore space and other galaxies but haven’t explored all of our oceans yet?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx61m9w",
"fx621pg",
"fx6273s",
"fx62k2k",
"fx62hgd"
],
"text": [
"We have not explored \"other galaxies\". We have sent one probe to Pluto, it took pictures of one side of that planet (I'm not IAU compliant). We've explored some of all the oceans, mostly the top part. The bottom part is hard to get too and mostly boring. Nobody with the money wants to spend it on boring deeps.",
"We have never explored other galaxies. As for oceans, we haven't been to every square inch of ocean floor. We've still mapped it out, we just have no reason to visit it. I mean, it's not cheap to get a submarine down there. Why bother?",
"Between us and the interesting objects in space is mostly millions of miles of nothing. We can see very far because of it. And by \"see\" I also include gathering EM radiation not in the visible spectrum, so that lets us extrapolate all kinds of facts. With the ocean, there's enough stuff in the water to make it cloudy beyond a few hundred feet or so even in the best conditions. So we'd have to physically send probes to scan the ocean floor at that narrow range. If the ocean were as clear as space, we could see everything of note from an airplane (or ironically, from a satellite).",
"We can't explore other galaxies - in fact, we can barely explore our own solar system. We've only sent a handful of man-made objects outside of Earth's little neighborhood - like probes to give us information about the other planets and a few that have been sent out farther to exit the solar system. Exploring even other systems outside of ours, let alone galaxies which contain millions and billions of stars is well outside of current possibility. As for the ocean, we've explored some of the depths, but there's not nearly as much interest about mapping the sea floor or doing studies of the deepest areas because it's expensive and uninspiring. Aside from some potential biological and geographical discoveries, there's not a huge amount to be gained from deep-sea exploration, and it takes a lot of effort and money to create the kind of equipment that can operate under that pressure. We can observe space much more easily because space is empty, and we can understand a lot about it from basic observation.",
"We went into orbit and the moon because we were in a Cold War with the USSR and didn't want them to get a strategic advantage if it ever came to actual war. Now the main reasons to go to space are still defense-minded. GPS is owned and operated by the US government. Most studying of space occurs with telescopes, where we're just observing and analyzing data that makes it to our instruments from far corners of space. In order to explore the ocean, we have many more problems that need to be addressed. You need to have a constant source of power; there's no sunlight so you need to bring your own or be able to recharge. You need to withstand the pressure trying to crush your instruments, ocean currents pushing you in all directions, and be able to document and transmit everything back to people who can analyze it. If you send people down, that adds even more complications. Roughly 75% of the Earth's surface is covered in water, how big are the machines you're sending down there? Most importantly, you need people to fund it. Most people won't unless they can profit from it."
],
"score": [
6,
5,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmmcxu
|
How does a computer know a car is a car, even if it’s a different shape, or color etc.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx61xt3"
],
"text": [
"Well, in a way, we don't know. Google and their competitors all have algorithms that look at pictures and try to analyze them. These algorithms must be trained by being told what is and isn't a car. They are trained with huge amounts of data. Google's captchas are actually part of how they train theirs. They have the user click on all stop signs or streelights or whatever and then their AI learns from this data. But because we are training it, the program is sort of writing itself, and so we can't always say exactly why it works."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmmuqb
|
What is network jitter?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx66xw6"
],
"text": [
"Jitter is a variation in the timing from one network packet to the next. Think about it like cars on a road. If the cars went by perfectly evenly spaced then there would be 0% jitter. If the average time between was say 10 seconds but some came as soon as 8 seconds and others as long as 12 seconds then there would be 2 seconds jitter. Since 2 is 20% of the average (10) then there is 20% jitter. Now just replace cars on the road with data packets on the network. Jitter generally doesn’t matter in most network communications like web browsing or email. But on streaming services like voice, the quality of the sound is related to the expected timing between the data packets carrying the voice data. If there is too much jitter disrupting that timing then the quality of the voice will be degraded. It gets more complicated than that with algorithms to avoid / compensate for jitter and other network imperfections like latency and packet loss, but that gets above ELI-5."
],
"score": [
17
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmqjvj
|
Why do screenshots taken from the same phone have different file sizes?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx6qjfg",
"fx6qkoo"
],
"text": [
"Photographs are rarely stored as raw data. A 1920x1080 image would be about 6 megabytes stored raw, but file compression algorithms let us get it smaller than that. These algorithms find patterns and shortcuts to use less data to store the same image. Depending upon the patterns that are used and how common they are in the image, it may wind up being significantly larger or smaller.",
"Images are compressed. Compression works by removing redundancies in the file, so the compression level depends on the contents of the image - some can be compressed more than others. For example, a completely blank image can be very easily compressed, while a random noise image can barely be compressed."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmrw2c
|
Just how does RAM work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx6zpz1",
"fx6yith"
],
"text": [
"Ram is a form of memory (bit storage). In a computer you typically have a hierarchy of memory depending on how physically close to the CPU you are. For illustration let's take fairly new processor running at 3.5 GHz. One clock cycle happens in 277 pico seconds (1/3.5 GHz) . Speed of light being 3x108 m/s that means an electrical signal can travel 0.085m in one clock cycle (fundamental physics apply here.) That gives you (very, very roughly) about this much space to travel in one clock cycle: < -------------------------------------------- > A memory heirarchy typically looks like this (I added a typical cycle time comparison on a read to highlight the magnitudes of difference): • CPU -- > Registers (1-2 cycles) • Registers -- > L1 (level 1) cache (2-5 cycles) • L1 cache -- > L2 (level 2) cache (3 - 7 cycles) • L2 Cache -- > (and so on, depending how many caches you have) • Cache -- > RAM (~20 cycles) • Ram -- > Hard Drive (~ > 100 000 cycles, significantly lower with an SSD and depending on connection to SSD, especially for random access, but still easy way more than ram) Obviously, there is a massive gap in access times between the CPU and Hard Drive, which ram aims to reduce. Here's how it typically works: When your CPU needs a certain part of memory to do work on, it issues a read to a certain address of memory. The memory management unit then figures out whether or not that address line is in the cache. It propagates through the memory hierarchy, and if it is not in the RAM then it searches the Hard Drive. Most programs feature spatial and temporal locality. Spatial locality refers to the fact that instructions and data are usually near one another in an address space. This means when a block of (for example) instructions are in the cache, the next sequential instruction is usually close by. For example, the instruction at address 1000 is usually followed by the instruction at address 1001. Temporal locality refers to the fact that a program tends to spend most of its time in a small portion of code doing the same thing over and over again. This means that if we put most of the data that a program needs in the RAM our program will run a lot faster, as it needs to make less and less reads from the hard drive. If your RAM is used up by many processes it noticeably slows down your computer as more hard drive accesses must be made (this is usually referred to as thrashing which sounds cooler than it really is). How does RAM actually work? Basically think of a giant spreadsheet of numbers each with an address - each has some data in it as a series of ones and zeroes (represented by a voltage levels, high and 0v). When you ask the ram for a certain cell (column 1, row 1 for example) the RAM controller connects the contents of that cell to the output pins of the RAM. This is what the CAS (Column Address Strobe) specs on Ram refer to: this is the time it takes for the RAM controller to put the contents of a cell onto the output pins from the moment you ask for it. In the most common form of computer memory, dynamic random access memory (DRAM), a transistor and a capacitor are paired to create a memory cell, which represents a single bit of data. The capacitor holds the bit of information -- a 0 or a 1. The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state. A capacitor is like a small bucket that is able to store electrons. To store a 1 in the memory cell, the bucket is filled with electrons. To store a 0, it is emptied. This is 1 bit of data. Now stack a whole heap of these over and over again into a giant array and you essentially have RAM. One other noteworthy point is that the capacitor is constantly loosing charge to ground (and therefore voltage), so it slowly (with respect to the clock cycles) is tending towards 0. RAM needs to be constantly refreshed to keep the voltage levels and their the stored information accurate. If a cell is at 0V, the refresh does nothing to it and recharges any cells at 1. For this same reason ram has no storage capability unless it's powered, but has the advantage of being significantly faster to store and retrieve information.",
"When you open a program or start a service, the files are read from the hard drive, and then put into memory were the CPU can access the information and do the instructions. Storage medias like punch cards, floppy disks and mechanical hard drives used to be a slow, and to pull data from directly was slow. Now lets say you open a Notepad, and start typing. That program and what you are typing is being stored in memory. Until you save, then a file is written to disk. This is happening on your browser and any other program you have open. Take a look at task manager, all of that is being read from memory, With how fast SSDs are. I can see how the lines between HDD and RAM can be a bit blurry. But memory is designed for fast retrieval of data. A hard drive wouldn't be able to keep up with the demand. Edit: If you want see something that will blow your mind. [Check this out]( URL_0 ). In this Super Mario Game they write a program to memory using the game, and then play the new game they written in memory."
],
"score": [
24,
5
],
"text_urls": [
[],
[
"https://youtu.be/OPcV9uIY5i4"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmscp8
|
What is basically the difference between an 1GB SDcard and a 1TB SDcard if they're the same size,shape and weight?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx70p6i"
],
"text": [
"Density of the components. That's why is harder to make higher storage because you need to fit more in the same space"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmxbgo
|
How do social media “bots” work? Are they like programmed trolls? How do their accounts/comments seem as if they could be a real person’s?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx7u2qx"
],
"text": [
"A lot are actual people. There are offices in some countries full of people getting paid to maintain dozens to hundreds of accounts and shitpost constantly all day long. Also commonly called a Troll Farm. It sounds crazy, but think how many posts you could make in a solid 10hrs if you were just swooping in, posting some sort of divisive one-liner, and then dipping out to let the people argue amongst themselves in your wake. It's probably the highest rate of return of anything you can spend your Psy-Ops money on."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hmyhup
|
How are some songs able to remain on YouTube for years (via unofficial channels) while others are taken down almost immediately?
|
For example, Garth Brooks is notorious for sending out DMCA requests liberally on all unauthorized platforms, yet I can search YouTube and find all of his songs easily that have been there for years and are obviously unofficial channels. I know YouTube has an algorithm, and Garth Brooks is a pretty well known artist, so I don't see how the algorithm could not detect and remove these. Garth himself could search and find these as easily as I could, I imagine, so how do they stay up?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx82i8q",
"fx8g1o5"
],
"text": [
"Yuotube has a couple of different ways they allow people to deal with violations. One is to have the problem video removed. Another is to allow it to remain, but to demonetize it for the original uploader. That is, if there is an ad on the video, the money goes to the copyright owner (the music company, in this kind of case) and not to the person uploading the video. Many artists only care about \"piracy\" in the sense that they aren't getting paid, so if YouTube provides a method that they get paid for someone listening to their songs even if it's just some random internet guy posting, they're OK with it.",
"Try listening to some of that \"Garth Brooks.\" Nearly all of it is someone else singing and definitely not Garth."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hn1uix
|
How do instructions from earth work to control robots in space?
|
ELI5: How are the Mars rover and other space exploration robots able to still receive instructions from earth given how far away they are and the time it takes for the instructions to get there?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx8n7v1"
],
"text": [
"The instructions are in the form of a \"program\" that you want the robot to autonomously perform. It's not like driving an R/C car around on the living room floor."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hn4wd9
|
What is the difference between coilguns and railguns?
|
What are some of the key differences in how they function and what that means in practical applications?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx987zh",
"fx96k8n",
"fx980c1"
],
"text": [
"A coilgun have a coil wrapped around the barrel creating an electromagnet. When you pull the trigger you activate this electromagnet which attracts the projectile to it. When the projectile is moving past the electromagnet you turn it off so that you do not pull it back again. A railgun on the other hand only have two rails going along the barrel. The projectile creates a short circuit between these rails. If you apply a current through the projectile you are essentially creating a coil with only one turn which acts as an electromagnet. But as you activate an electromagnet there are forces pushing it outwards. This is often the source of the buzzing sound you hear in transformers. But since nothing is holding the projectile in place it will just accelerate forward until it loses contact with the rails. Coilguns are very attractive at first compared to railguns. All the wires are insulated so there is no risk of shock or short circuits. There are much less friction and currents are lower so less heating of the components. You also do not have to worry so much about the projectile losing contact with the rails as it travels down them. However a coilgun requires a lot of precise components to open and close the circuit at the exact right time. For something small like a BB gun this is a nice little challenge. However for much larger projects there just is not components that are both large and precise enough. On the other hand the issues with railguns does not grow as the size of the gun is increased. In fact if you get enough energy some of the problems resolve themselves, such as heating the projectile enough that it contacts the rails much better. And there is no active electronics involved, just capacitors, two rails and a switch. This is why we are actively researching railguns to possibly be used in future warfare while coilguns are more of a novelty concept for small devices.",
"Coilguns fire magnetic bullets. It requires the projectile to be a permanent magnet. Railguns push a projectile with a conductive sled between two high current rails. The projectile can be made of anything.",
"Railguns have two conducting rails as the name implies and the projectile forms a bridge between them and slides down the rails and shoots out the end. Railguns require huge currents and the rails take a lot of damage from the projectile sliding down them at high speed, the electric current arcing to the projectile, and the insane repelling force between the two rails. This is why railguns have tons of bolts running down their length, they want to rip apart. Any projectile will work, if its not conductive then you put it on a conductive sled that drops off after launch. Coilguns use a coil of wire to create a magnetic field to push the projectile out. In the non-weaponized sense we generally call these solenoids and they're used all over the place, its just a small coil that causes a little metal pin to pop out. Now if you take that coil, make it bigger, put a lot more power through it, and let the pin shoot out you've got yourself a coilgun! Coilguns don't need super high levels of current as you can use more voltage and more windings to generate the higher magnetic field rather than just moar current like a railgun which has no windings. Coilguns do require magnetic projectiles (or something that can have magnetism induced in it) which limits the options, but they also have the advantage of not trying to rip themselves apart or wearing significantly with each shot. At the end of the day, making a strong/efficient railgun just requires a big ass capacitor bank, two conductive rails held together nicely, and a conductive projectile. A coilgun is a fair bit more challenging to make an efficient coilgun and you start needing staged coils and careful timing to sync up and get your projectile to high speed. DARPA made a 45 stage coilgun mortar and only managed to pull 22% efficiency out of it meanwhile the Navy's Railgun is around 50% making it a much better use of power"
],
"score": [
8,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hn5jr9
|
If a phone can have the shutter speed set to 1/4000 of a second, why can't it record video at higher than 240fps?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx9h381",
"fx9mhhl"
],
"text": [
"A phone can take a still image with that shutter speed, but to do it more than 240 times per second also means you have more images to store on the phone. Moving those images from the sensor, to the the phone memory, can be a bottleneck to performance. Even high end dedicated DLSR or mirrorless sports cameras like the 20 frame per second Sony A9 have limitations because they have a bottleneck moving the photos onto the memory cards. Very high frame rate video cameras exist but of course the faster they are, the more money they cost. There are other complications also. For example, capturing an image at 1/4000th of a second shutter speed usually requires a lot of light. If you watch the slo motion channels on youtube, you may notice the super slo motion clips are darker, because they are using such fast shutter speeds. I hope this helps.",
"So these answers are partially right and partially wrong. The time it takes to read the data is a few microseconds, which is much much faster than the exposure time anyway, but it has to do with how the camera sensor works. As far as I know all smart phone cameras besides the iPhone IR camera use what's called a rolling shutter. It's an electronic shutter of course and is really a CMOS sensor that can be turned on and off to capture light at pixels very fast. It's possible to have a global shutter that works similarly to a physical shutter by turning all pixels on to capture light at the same time and then reading them all at once, but you start to get problems with noise and therefore image quality and it gets exponentially more expensive to avoid that with more pixels and faster speeds. So rolling sensors instead expose each line of pixels individually, staggering them so that there is time to read each line one at a time. AKA lets say it takes 5 microseconds to read one line of pixels; in your example it exposes each pixel for 1/4000 of a second, or 250 microseconds. It will start exposing the first line, then the second 5 microseconds later, and so on. A modern camera might have upwards of 5000 lines of pixels. Even at just 5 microseconds per line, that means the last line of pixels actually takes a picture 25 milliseconds after the first, and is why taking a picture of spinning fan blades and other fast moving stuff looks weird on a phone camera. For video it makes each image one at a time so it has to wait until all of the pixels are captured and create an image for each frame. In the above example you expose pixels to light for 1/4000 of a second but it actually takes 1/400 of a second to capture the whole image/frame, plus a bit of time to \"put together\" and store the image."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hn77we
|
How do electronic devices work?
|
Say like a greeting card that plays a sound when you open it, or a Staples ‘Easy Button’ that plays a ‘That was easy’ sound when you push it. Or even a calculator.. What is _happening_ exactly when you trigger the device? What are all those transistors and colorful bits on the inside of a radio doing? etc. it’s basically magic to me, please blow my mind!!!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fx9qj05"
],
"text": [
"Well, there's a lot to it, but I'll try to give you a short version. After all, this technology has been developed over decades, and a lot of very bright people have put in a lot of effort. Many devices work on \"binary digital logic\". That means that operations are reduced to manipulating information as if it is a bunch of 1s and 0s. Collections of 0/1 are used to represent more complex information. Imagine a light bulb, a battery, and a switch. Close the switch and the circuit is completed and the light bulb is connected to the battery and turns on. Open the switch and the bulb goes out. Now imagine that there are two switches in series. The bulb only turns on if both switches are in the \"on\" (closed) position. If either or both is \"off\", the light bulb is off. That circuit is a logical AND circuit. Switch A and B both need to be \"on\" for the result to be \"on\". Now imagine that instead of the two switches A and B being in series, they are in parallel. Either one being turned on completes the circuit and turns on the bulb. The only time the bulb is off is when both A and B are off. That's a logical OR circuit. In modern Integrated Circuits, we don't use mechanical switches, we use transistors. They are devices that can be used like switches, except there's no mechanical part. The on/off function is determined by an electrical signal. So instead of switches in our circuit(s), we use transistors. And the light bulb can be another transistor. So using transistors, we can implement simple binary digital functions that follow logic rules like AND and OR, as well as others. And those \"logic gates\" can control other \"logic gates\". Each one is simple, but they can control many other simple logic gates, which can in turn control others. By combining many simple gates we can build up more complex functions, and out of those even more complex functions, etc. etc. It's like making a Lego block out of small Lego blocks, and using those larger Legos to make even larger Legos, and so on. We can also make things that aren't really logic gates, such as memory elements. Those can also control things, but they are programmable. The things they do can depend on their content (whether they contain a 1 or a 0). Combining memory with logic allows us to change how a circuit operates. Using all those techniques (and others) we can build circuits that are extremely complex, even though they are built out of very simple things. Those simple things are very very tiny so we can have literally billions of them. They are also very very fast. Using this combination of simple things organized to make more complex functions happen along with having billions of them at our disposal working very very fast makes it possible to do all kinds of things. **TL;DR** - Lots and lots of very fast \"switches\" organized to do complex things."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hn8c2b
|
Why can't you hear your own voice from the other persons speaker through their microphone during a phone call.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxa19wg",
"fx9sova",
"fxa1v4r"
],
"text": [
"It's called phase inversion. Your phone/laptop knows the shape of the audio wave that is being sent out and flips it upside down. This makes the peaks into troughs and vice versa, cancelling out those particular sounds it picks up through the mic, but allowing your / other person's voice to be singled out. It's the same principle used in Alexa / Google Home so it can hear you more easily even when it's playing music.",
"The speaker is usually too quiet and the phone microphone far enough away to avoid picking it up. If one person has the call on \"speaker\" however the other caller will usually hear their own voice echo back because that speaker is loud enough to be picked up and sent back.",
"Most video/voice software these days comes with “Acoustic Echo Cancellation”. Basically your computer knows the sounds your speakers are making. If your microphone hears those sounds, they get removed before sending the mic sound to the “far end”. A different tech referred to as “Half Duplex” is used by old-school speaker phones. This is when only the speakers or the mic is active at one time. Not both. If you start talking, it mutes the speaker. If you are not talking, it unmutes the speaker."
],
"score": [
8,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hn9xu3
|
How is it even possible to ban an app?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxa2dh5"
],
"text": [
"You issue an executive order to Google and Apple to remove the app from the store. They'll either fight it because it's not really legal for that order. Or they say the fight isn't worth it and pull them from app store."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnae67
|
Just how can a little $399 Go Pro with little battery shoot in 4K 60fps where as the large and cumbersome $2000 prosumer cameras that additionally consume power bricks of power from companies like Sony just do 4K 30fps?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxa7epw",
"fxa8lhg"
],
"text": [
"4k is a resolution, effectively the size of the picture, and the fps is, well basically pictures per second. *Generally,* you can expect the more expensive cameras to be taking \"higher quality\" pictures. There are a lot of aspects that can fall under that vague term, such as a less compressed file format that's easier to edit, better exposure in low light, higher color accuracy, and a wide variety of other things. And while you may not be able to tell a noticeable difference between the two when downscaled to fit onto, say a reddit post, these differences are often noticeable under scrutiny.",
"Output resolution isn’t nearly as important as sensor size. When scaled up to a 65” 4K tv you’ll notice a difference in clarity and color."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnasd7
|
Why aren't you allowed to use question marks in file names?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxa7cvj",
"fxa7kn1",
"fxa7j9i",
"fxak93z"
],
"text": [
"There are 9 symbols that windows uses for search functions, command line codes, commands, etc. it’ll prevent you from using them in file names because windows won’t be able to differentiate it later on. It won’t know if it is part of a file name or a command/extension/etc if it allows you to use them for both.",
"Because question mark is used as a wildcard character for \"any single character\" in the file search function. For example test?.txt is what you write into file search if you are looking for testA.txt, test5.txt, testt.txt, but not test12.txt.",
"A computer needs to have some reserved characters that are not ever found in file names, so that it can use those characters for computer stuff like searches, command line entries, and designating file locations. Characters like ?, < , > , etc are reserved for stuff like that, and if you could use them in file names the computer would get confused. For example, let’s say a computer designated file paths with “ > ” like Users > yourname > desktop > file_x. If you could use > in file names it wouldn’t know if that text is a file path made of folder/file names separated by > , or one long file name.",
"Quite often the constraint isn't the actual way information is stored on the disk, but is instead restrictions are intentionally placed there to let software, frankly, be lazy and make assumptions that make their life easier. Speculating a little, not allowing special characters made it easier to dissect text-based user input back in the DOS days. Something people don't often give Microsoft enough credit for is that Windows bends over backwards for backwards compatibility (for *properly* written software.) Unfortunately, IMO, this means they leave in place a lot of pointless restrictions because it keeps a promise they made in the past. The wackiest one I've run into is the inability to name a folder [\"aux\"]( URL_0 ). Something worth mentioning is that there are many different schemes for how to organize and store information on disk drives. On my laptop which runs Linux I can actually name a file ~`!@#$%^ & *()_+=-[]{};':\",. < > ? but I can't put a '/' in the name, because / is how the system knows where to break up the name of the folders a file is in."
],
"score": [
8,
5,
5,
3
],
"text_urls": [
[],
[],
[],
[
"https://stackoverflow.com/questions/26420621/unable-to-create-aux-folder"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnb9qm
|
Is there a specific reason as to why printers use cyan as opposed to just blue?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxabrg6",
"fxab72c",
"fxacg1a"
],
"text": [
"There are three primary color, Red, Green, and Blue. Paints work by absorbing certain colors, and reflecting the rest. If you take away all the Red, you are left with only Green and Blue. Green and Blue make Cyan. The Cyan paint is basically the paint of Not Red, it absorbs all the red light and reflects the rest. Like wise take away the Green, you get Red and Blue combined. Red and Blue make Magenta, the paint of Not Green. and Take away the Blue, you get Red and Green combined. Red and Green make Yellow, the paint of Not Blue. Mix these together and you can absorb the color's you don't want and reflecting the colors you do work.",
"Cyan is a special shade of blue, just as Magenta is a special shade of red. Yellow is just....yellow though. Cyan,magenta and yellow (along with black for brightness control) can be used to make literally every single color you can perceive. A pure blue and a pure red cannot do that",
"This relates on how you can create colour. As other said, eyes use RGB. YOur tv uses rgb. It allows additive colour generation - it only means if you print the same amount of red, blue and green you get white. Now, to print on white paper, rather not put any ink. But you want to create black. You need subtractive colour generation. Obtained by adding cyan, magenta and yellow. Now, given this is not perfect with ink, people likes to use a black toner to have better contrast on paper. You may look at the diagram of: URL_0"
],
"score": [
8,
6,
3
],
"text_urls": [
[],
[],
[
"https://en.m.wikipedia.org/wiki/Subtractive_color"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnc1p9
|
if TikTok is Chinese spyware, what exactly are they spying for? What benefit does the Chinese government from their users data?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxaezvg",
"fxaju89"
],
"text": [
"To work, TikTok needs access to your camera, microphone, photos, video library, and social media profiles. With all of that, it also gets your GPS location, and activity throughout the day, regardless of whether you use the app or not. That’s an enormous amount of useful data to have on anyone. But think of all the celebrities on TikTok... there’s a lot of crappy things you could do with all that data.",
"Social engineering. If you can understand how a population works, you can figure out a way to manipulate them into doing things in your favor. They would use all the metadata (location, face, contacts, voice pattern, etc.) From the app, create a diagram for that, and see what makes people tick."
],
"score": [
7,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnffxb
|
Why do clothes need water to produce?
|
I have heard about how much water clothing takes to produce but I wonder why this is? The numbers quoted seem very excessive.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxaxv03",
"fxaz8d7"
],
"text": [
"It takes into account the entire porduction process. Take cotton for example. Cotton is a very weak crop and requires huge amounts of water (and herbicide/insecticide) to live long enough to harvest. Then there is the water that is used in preparing the gotton after harvest to clean the crop and process it. Then the water used in transport of the crop to the textile mill that will spin the cotton into usable fabric. Water is consumed at each point in the process in this way and by the time a t-shirt is made, hundreds upon hundreds of gallons have gone into making it. Now the t-shirt is either bleached or dyed, which uses water and chemicals. After the bleaching and dying of the fabric, the fabric is washed again to remove any harmful residue from the dying process. It adds up over time.",
"Water use in crops is a reference to how much water is required to grow it BUT NOT how much water is actually added or used by humans. How this works is its a calculation of rainfall or irrigation that would be needed to grow the crop. So basically if a shirt needs one kg of cotton, and it requires 1L of rainfall or irrigation to produce 1kg of cotton. Then a shirt uses 1L of water"
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hnfg0w
|
What is the difference between Adobe Photoshop and Adobe Lightroom? And when to use each one?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxaxqce"
],
"text": [
"PS is used to modify photos individually, add/remove objects, etc. LR is used to process photos individually or in batches, create catalogues, etc. There is a fair degree of overlap in the software. I prefer to use LR for most things, plus it allows me to quickly organise sets of photos. I use PS for focus stacking, object removal, and that's about it. Depending on what you're doing will dictate which you need to use, but I almost always import with LR, do a basic process (levels and lens correction), then open in PS if needed."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnfpzm
|
Why do “missing textures” in video games usually end up purple?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxazxry",
"fxb3ccz"
],
"text": [
"Because it’s not a color that you should normally find during gameplay, the bright neon purple sticks out like a sore thumb, so you know something is messed up",
"It actually doesn't. By default missing texture is transparent. It's the dev's job to setup a backup texture (usually a simple color). In most cases it's a purple texture. It sticks out and make it easy to see. But in some older games, you could see some some more elaborate textures like big crosses or checkerboard-like texture."
],
"score": [
39,
24
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hngn0z
|
How do different video formats change the size of a video, even at the same resolution and frame rate? Isn’t it the same video you’re watching?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxb4ykk",
"fxbnrcx",
"fxcle12",
"fxbwmas"
],
"text": [
"There are two things that you can tweak. The first is the compression algorithm. This will be things like MPEG versus h.264 or h.265 algorithms. They describe how to strip down the video file to as few elements as possible to reproduce it later. Essentially, you trade storage time for CPU time to compress/decompress it. The second is the lossy factor. Most video compression formats do not attempt to serve back the exact same set of pixels. Instead, you get something that is good enough to be recognizable on the other end. Of course, the amount of detail you want to keep is an adjustable factor in the compression algorithm. You can take the same source video and throw it into the same algorithm with two different settings and get different quality video out the other end.",
"There is more to a video than its resolution and format. If you're learning video editing you'll have to learn about rendering and encoding too. Encoding/compression is nicely covered in a simple answer above. Rendering also has options, namely resolution but also bitrate. Super simply, the bit rate is the amount of data that will be put in the video. Imagine a water pipe. Resolution is the length of the pipe, and the bitrate is the amount of water you wanna flow through it. The file size is the diameter of the pipe. If you want more data, you'll have more detail, but will need a bigger file to hold it all together. That means more bitrate (compress less) If you use a lower bitrate (compress more) you'll still have the exact same number of pixels (résolution) but many of these will just be duplicated by the algorithm to fill the gap. Essentially the algorithm does this : if it's green to the left, right, above, and below, I can make that center pixel also green because it probably is, and save space because I don't need to remember it now\". Try and render a video with really low nitrate and you'll just see big squares, but a very small file size. Now I wanna add about compression, because you can have a decent video with low bitrate if the video has very little pixel variation. Imagine a video of a slideshow . One frame stays the same for 20 seconds, then a new frame appears and stays for another 20... There you can lower the bitrate like crazy because it's a single image, so a screencast of you typing text for example can be very light, because only the letter you're typing is the difference between the current image and the next image,the algorithm knows to only change those few pixels, and that's the only information going through the pipe. If a pixel does not change, the information to change it simply doesn't travel. So, small pipe there is fine. It's a very simple and rough explanation, but it covers the general idea behind your question :) although the answer could be much more complete and accurate, I hope it's enough for you!",
"For an ELI5 it may be better to think about picture compression. A movie is just a string of pictures after all. Think of a very simple picture. You need to tell the computer how to save this image in a way it understands. The most basic way is to map every pixel. Pixel number 1 is black. Pixel number 2 is black.... This is rather repetitive and can use more space than need be, but is accurate. We can compress that a lot by saying \"pixels 1 - 395 are all black, then 396 - 412 is yellow. For a basic example. If you have a large block of the same colour that saves a lot of space, but if each pixel is a different colour, it might end up costing more space. To compress a bit more we can start using mathematics, \"there's a black background, with a yellow circle of diameter X in the centre... \" That saves a ton of space, but if the maths isn't quite right, the picture might end up a little off... When you have a dozen different ways to compress the same picture, a dozen different ways of expressing each one, and a dozen different maths sets you can use, each is going to have varying sizes, Or levels of accuracy. Some might be better suited for a certain kind of picture - on the internet we want a small size, the quality isn't as important, but you want the page to load at a decent speed. Your round-the-world hike you will what the pictures at full quality, even if it uses a lot of space on your PC. So you won't use the same compression for both these cases. Video compression is the same. Its all just different ways of taking a really big, detailed picture, and making it smaller so it can be downloaded, or streamed, or saved. Whatever. But each different method will have its own pros and cons.",
"Video formats are like different languages. Some languages have words to describe very complex situations or objects and others have synonyms which can be substituted. Different formats are simply different languages expressing the same sentence. But It takes time to convert the language, and to find the best fitting words. So Hello might be converted into Ola to save space, but you could also replace it with Hi which is even shorter."
],
"score": [
65,
8,
6,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnk2z5
|
why do 3D glasses have one red lense and one blue lense?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxbsf7n"
],
"text": [
"In order to simulate 3D you need each eye to see something slightly different. The simplest way to do that is with colour filters. A red lens will block blue light and vice versa. A blue object seen through a red lens looks black. Against a black wall it might seem invisible. Now you project a movie with only red and blue projector blubs - red for one eye and blue for the other eye. The two filters will keep the images for each eye separated even though the viewer is watching a single screen."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnkzv3
|
is awd faster than a fwd?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxby0g1"
],
"text": [
"AWD = all wheels drive (presumably 4) FWD = front wheels only drive Not most of the time. AWD has many more moving parts, thus higher inertia and more places for friction. There are conditions, like snow, ice, desert sand, ... where AWD is faster; but it's perhaps not a super-good idea to drive really fast in those conditions. AWD and FWD have the same stopping distance, so going faster just might mean getting into more trouble. AWD has an advantage in slick conditions, you can maintain better control. Not that you'd use that to go faster, but staying on an icy road is a good thing."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnndt0
|
Why does "on hold" music on a phone sound like it's under water?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxcebzv",
"fxcx6uw",
"fxcem90",
"fxd3to2",
"fxd7cw0"
],
"text": [
"Most human voice is between 300 Hz and 3000 Hz. So most phone systems are designed for these frequencies. In addition human voice have a lot of familiar patterns so you can save bandwidth by compressing it with special algorithms for voice. However music is usually between 30 Hz and 20,000 Hz and follow very different patterns. So the high and low notes will get cut off and the voice compressor will mangle the rest of the notes. This makes the music very strange to listen to.",
"[Compression and bandpass filtration.]( URL_0 ) That’s a video by Tom Scott with the most accessible, on-topic explanation that anyone could hope for. TL;DW compromises to quality are made in the name of efficiency, especially for non-voice sounds. - The data stream is heavily **compressed** by algorithms designed to focus on preserving voice patterns, not music patterns. And this is made worse because the decompression needs to be runnable on old mobile devices with primitive processors. - The sound waveform itself is **band-passed** to the frequency range covered by human voice (a few hundred to a few thousand hertz). Compression artifacts are the main reason behind the specific underwater-like effect.",
"Basically it's becomes it's being compressed into the same frequency range as the majority of human voices. The POTS (Plain Old Telephone Service) can't carry the frequencies above/below that. More specifically, it is restricted to between 300 and 3,000 Hz, where your hearing is 20 to 20,000 Hz range. The restricted frequencies mean that music doesn't sound like it's supposed to.",
"It's like a rainbow. Music is the full ROYGBIV, but the phone only allows for Orange and Yellow. Our voices would be orange and yellow. The phone is designed for voices so it cuts out the other colors.",
"In addition to the technical problem of insufficient bandwidth for music, there is also the legal issue of licensing. A business must have permission to play a song and because they don't want to keep track of every time it's played they will go with a royalty-free (pay one, unlimited plays) license. A royalty-free music track is way more expensive that the same track sold to a consumer (for generally less than 1$). When all this music was originally on cassette tapes they would have made [copies of copies of copies]( URL_0 ) of the cassettes as they wore out. Every time a digital storage [PBX]( URL_1 ) started to die or was upgraded they would have placed the telephone handset on a laptop's microphone so some intern could record the hold music and load in in to the new system."
],
"score": [
344,
65,
45,
10,
5
],
"text_urls": [
[],
[
"https://youtu.be/w2A8q3XIhu0"
],
[],
[],
[
"https://en.wikipedia.org/wiki/Generation_loss",
"https://en.wikipedia.org/wiki/Business_telephone_system#Private_branch_exchange"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnuic6
|
how does a water heater work? I have the shower running hot water & the sink running cold water at the same time. How does this happen/work?
|
The question is pretty self-explanatory but how does one source of water in a house supply different temperatures of water to different locations at the same time?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxdp2hd",
"fxdpd5a",
"fxdpnnl"
],
"text": [
"A water heater takes in cold water and heats it. The hot water is delivered with pipes to every faucet in the house. You have two pipes going to every faucet, one cold and one hot. Check under the sink and you'll see them. Where you turn the faucet determines how much hot and how much cold water gets put out.",
"There are two different pipes feeding each spigot or faucet. One is from the hot water heater and the other is cold water from the street. You change the valve openings so that more or less hot water goes out the faucet. You can adjust the amount of hot water coming out of each faucet. different faucets can have different temperatures because you select how much hot and how much cold water will come out of each",
"I'm not a professional plumber by any means, but my understanding from installing a tankless water is this; both lines are pressurized, one goes straight to city or well water, and that's your cold tap, the other goes into a tank that consistently keeps water hot utilizing a thermostat and gas or electricity to heat the water. While your shower is running, its pulling water from the hot source and the cold source simultaneously, and when you turn on the sink at the same time, its pulling water from just the main source. When you flush a toilet, its pulling a significant amount of water from the cold source, resulting in a deficit in the shower, leading to you just getting the hottest water. Sorry for bad english, english is my first language but I'm an idiot."
],
"score": [
6,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hnwxhf
|
How does “maps” on my iPhone can not only accurately locate my location while I am driving but can also tell the traffic conditions, speed limit etc ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxe6vsy"
],
"text": [
"getting you position is just applied GPS, which is a whole topic in itself. TLDR version - it uses the time needed for signals from your phone to reach various sensors to tell where you are. speed limits are a product of good data collection. Google, apple, and lots of others are interested in what traffic laws apply where, so that they can make good navigation software. To get this info, they send cars to map out the roads, ask governments for specifics, and pay people to share what they know. traffic conditions are a combination of the two (afaik). if you know the speed limit, which is basically the expected speed, and how fast people are going, you can pretty easily say if things are going well or not. EX: you know the speed limit is 50, but all your data says that people are going 5. something must be wrong, and it's likely a traffic jam. Other data sources (see above) can be employed to check for lasting traffic issues, like construction or an accident."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hnyjxk
|
How does mobile tracking works?
|
I watch a lot of crime shows and movies and a lot of them always have a sequence of someone getting tracked by someone like a computer expert or law enforcement officer and they always do it by locating their mobile location. So that made me curious as to how this whole technology works. Also is there's any Software or any tracking app that can track someone's location if we know there mobile number? I know that we can install some app in someone's mobile and that app can be used to track their location but if we don't have any physical access to the phone can it be still tracked if we just have their Mobil number.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxef4tv"
],
"text": [
"It can be done with a technique called multilateration. Your mobile phone is in touch with several base stations (aka \"cell towers\") in a short amount of time. The base stations record these interactions and, crucially, how strong the signal from your mobile was. Using this information from three or more base stations the position of your phone can be estimated. It works better the more densely spaced the base stations are, and the less interference there is from buildings or geography. This is sensitive enough to trace a phone to within roughly a city block under good conditions."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
hnz1g5
|
USB-C wiring
|
How many wires are in a USB-C to USB-A cable? Are there really 24 wires in a USB-C cable, and if so what are they connected to if USB-A needs only 4?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxeka1z"
],
"text": [
"The are 24 pins in USB-C to USB-C, but since it is reversible, that means there are really only 12 that are repeated. [This diagram says what each pin goes to on a USB-C connector.]( URL_1 ) In a USB-C to -A cable, there are 4 wires plus some extra connections in the USB-C end. [Here's a diagram showing how to connect C to A.]( URL_0 ) pins 1 and 12 (on both sides A and B) are your ground pins and connect to the ground pin of USB-A (pin 4). Pins 4 and 9 (again both sides) are the +volts and connect to pin 1. Pin A6 is data+ and goes to pin 3. Pin A7 is data- and goes to pin 2. I'm not sure why they say to not connect side B of the data pins, but apparently it isn't needed. Finally, you'll have to connect pin A5 to the +volt line using a resistor. All other pins are to be left unconnected since they don't have an equivalent to USB-A. Edit: added clarification"
],
"score": [
3
],
"text_urls": [
[
"https://i.stack.imgur.com/1agHR.png",
"https://i.stack.imgur.com/Aovh5.png"
]
]
}
|
[
"url"
] |
[
"url"
] |
ho50iv
|
How is old film converted into digital for DVDs or online streaming?
|
I was watching the wire on dvd and you can tell it was filmed on film just wondered how they convert it to digital??
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxfio5s"
],
"text": [
"They use a scanner, just like when you scan a photo. Well, not exactly the same type of scanner, but one specifically designed for scanning film."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ho52v4
|
What is a CPU core and thread? Why do they matter?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxfjhf5",
"fxfkp8c"
],
"text": [
"Modern CPUs basically are several small CPUs in one package. These are called cores. A CPU with more cores can do more things at the same time. Threads can refer to two distinct but related things: * Software threads: these are instruction sequences that can execute on the CPU. Programs can have one or more threads. * Hardware threads: these are instruction sequences that a CPU core can execute *at the same time*. Some cores only have one hardware thread and thus can only run one instruction sequence (ie: software thread) at a given time. Some core have 2 (and sometimes 4) hardware threads and thus can run 2 (or 4) software threads at a time. More hardware threads usually means better performance in highly multi-threaded workloads. Consumer CPUs usually have in the order of 4 cores and 8 threads. ************** All hardware threads running on a core actually share most of the core's resources and will sometimes have to compete with each others to run. This means that in a CPU with 4c/8t will be outperformed with a 8c/8t at full load (but will be cheaper).",
"Think of a thread like a car, and a core like a traffic intersection. Only one car can go through the intersection at a time. The intersection might use lights, or a roundabout to get cars to come through in a certain order. This is similar to how cores have different methods to get threads through in a certain order Your computer can only have as many tasks running at once as it has cores, but the operating system works like traffic laws. It gives right of way to certain threads in a more streamlined manner like a roundabout. A stop light let's one application or lane of traffic go at once, but the roundabout let's all lanes go depending on who is there first. It's not a perfect example, but it's similar to how these things work together"
],
"score": [
13,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ho7d7n
|
Why is it so hard for a robot to tick the box '"I am not a robot"?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxfzzdn",
"fxfyg1w",
"fxg498o",
"fxg7jku"
],
"text": [
"There's a lot more going on behind the scenes. In general, you see the simple checkbox captcha because Google already knows you're a human. With YouTube, Google Analytics, Gmail, Google Docs, Google ads, and thousands of other Google apps and sites, they are basically always tracking you. You're also almost guaranteed to be using a real/valid web browser, accept Google cookies, and you're acting like a real human. A bot might not have any Google history associated with it, might not be working inside a browser, might not be running the JavaScript that the captcha needs, might not make external requests that the captcha needs, might not accept cookies, their (possibly fake) user-agent might not match the features of a real/valid user-agent, etc. Google won't trust them, so they get the picture/puzzle captchas.",
"It's not difficult for it to do that. Clicking the \"I'm not a robot\" button just initiates a function to request \"may I please pass this captcha without solving a puzzle?\", and usually Google says \"ok, but a few more and you will have to start solving puzzles\". Once you do a few in a row, it will start requiring solving of a puzzle, which is challenging for robots. The reason that it is acceptable to bypass the first few, is that automated solving of Captchas is only valuable in large volumes. Basically anybody who wants captchas solved for their spam is only interested in wholesale captcha solving.",
"It's not hard at all for a robot to tick that box...but that's **not what the website is checking**. It's actually checking how you move the cursor as you go to check that box - the box itself is pretty meaningless. If your cursor makes a perfectly straight line directly to the box, and it happens within an instant of the website loading? Then it assumes you're a robot. If it takes you a moment to react, and you move the cursor in a straight-ish - but not perfectly straight - line? Then it assumes you're a human. \"But,\" you cry, \"can't the bot just do those things too? Make itself take a moment to react and make a not-perfectly-straight line?\" Well, sure...and then that means that whoever is making the \"I'm not a robot\" check needs to come up with clever solutions to whatever the bot is doing. Then whoever is making the bot needs to come up with a sneaky way around those changes. Then whoever is making the check needs to fix those holes. Around and around...the security arms-race never ends. But that's *generally* how it works: the box itself is a distraction; the real work is happening behind the scenes.",
"Semi related but you ever just feel a bit happy when you get that green tick next to the \"I am not a robot\""
],
"score": [
29,
6,
5,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hoc5vr
|
Why is the reception for musical hold for the majority of business phone lines so terrible?
|
You call a place get put on hold, and then the music sounds like it's being broadcast from 1932. There's static, it fades in and out, it stops, you think someone picked up, "Hello?", and then the same bad muzak resumes. Why? Sound technology has come so far.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxgytux",
"fxh12q2"
],
"text": [
"The quality of sound and music has come a long way, but the technology of the way we call didn’t evolve as fast. A standard for telephone is around 13 kbits. When you listen to music on Spotify its 96 or even 160 kbits. To compress audio from 160 tot 13 kbits, means you have to get rid of 92% of your data / information (since 13 is about 8% of 160). When you lose so much data, the quality greatly suffers.",
"Higher quality audio requires more resources, and in telephone systems, voice call quality matters more than hold music quality."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hoee1d
|
How does this clock show the digits through the wood?
|
URL_0
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxha0gr",
"fxhh7im"
],
"text": [
"There are likely 2 layers. One is thicker and has spaces cut out for the digits. One is very very very thin and lies on top. It's so thin that the light shines through",
"The clock is either covered with a very thin layer of wood, or paper made to look like wood. The bright lights of the LED digits can shine through the thin layer, because the thin wood or paper layer is semi-transparent."
],
"score": [
12,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hof9ls
|
If your monitors refresh rate is lower than your games FPS, how does FPS make the game look smoother?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxhgw39"
],
"text": [
"Because the monitor will get more recent frames to display, even if it's displaying the them at the same rate. Let's say you have a 60 Hz monitor and play at 60 fps. Let's also assume there's no active hw/sw solutions for the following problem. Your monitor shows the latest picture it received every 16.6 ms. Which means that there could be up to 16.6 ms delay from something happening and you seeing it. (ignoring all other delays) Your monitor shows a picture, but if the gpu sends it another picture just 1 ms later, we still have to wait another 15.6 ms to see it. You're seeing 15.6 ms old picture. Now if you play at 120 fps on that same monitor, you will se at most only 8.3 ms old picture. Because you can fit another fresher picture in the time between your monitor refreshes. Let's say that the monitor got a picture 1 ms after it's last refresh again, but now our game is running at 120 fps so we get another picture just 8.3 ms later, which is before the monitor can even refresh, so once it does refresh, it will see this more recent picture. You will be looking at only 7.3 ms old picture."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hofogk
|
How do airport X-Ray machines identify prohibited items?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxhi8od",
"fxhlpkc"
],
"text": [
"The machine doesn’t identify anything. There’s a human that’s sitting behind it looking at a screen that’s showing the images from the machine. If they see something suspicious they’ll pull the luggage aside and inspect it. Usually with you watching them for liability reasons.",
"The machine doesn’t identify anything. It simply provides an x-ray image which is displayed on a monitor that a person views. It looks no different than x-ray images you would get at a doctor, except instead of showing the inside of a body it shows the contents of a bag. It looks something like [the images on this page]( URL_0 ). It’s pretty obvious to the user what objects are weapons, and there are other tools they use as well to detect drugs and illicit chemicals."
],
"score": [
7,
3
],
"text_urls": [
[],
[
"http://www.teledyneicm.com/security/how-to-decode-an-x-ray-image/"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hoievy
|
why can my phone have no reception but still say I could make an emergency call?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxhzim3",
"fxhzlgd",
"fxi7hkf",
"fxi0i7f"
],
"text": [
"I believe emergency calls can route through any network/any tower. So the call can not be made on your carrier but could be picked up by another.",
"Because you have no reception with any of your providers antennas or any of its partner networks, but there are still cell towers nearby that aren't part of your providers network that you're able to use for making emergency calls as mandated by law.",
"Because of something called ESN - Emergency Services Network, a common frequency that all carriers use, and all phones have access to, even if you’re not using the carrier that the cell tower belongs to. Source: work in the telecoms industry building towers. Just finished a huge project to modify towers to run the ESN even when there’s a local power cut. Basically put ruddy great battery packs in.",
"Numbers like 911 and other emergency numbers when dialled can use any network company/carrier to make the call. The nearest cell tower is used wether it is yours or not."
],
"score": [
34,
31,
9,
5
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
hojdo2
|
Why is the abbreviation of 'Cyan, Magenta, Yellow and Black' called 'CMYK' and not 'CMYB'?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxi5wpa",
"fxi6d5s"
],
"text": [
"So the CMYK is referring to the plates of Cyan, Yellow, Magenta, and Key. This key plate is usually the last plate, and is what provided the details via lines and contrast in black ink. You can look at a print and see how there's usually not much in actual detail until the black key is used. As such it's also the key for aligning the plates, as the others need to be aligned in relation to it, since if its off at all, the whole image will look wrong when the lines and contrast are laid down.",
"B is easily confused for blue (RGB color), so a different letter is used. K also is generally understood to mean Key plate, (black provides sharp detail/contrast and is the most noticible color and so when someone is manually aligning different color plates it's the most critical (key) one) though there's a bit of argument as to if that's really the case originally. There's no definitive etymology on this. In any case it's likely a combination of these two factors that cemented K as meaning black in CMYK printing."
],
"score": [
45,
18
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
holeaq
|
How do diapers work
|
I’m a father to a one year old. I have never loved something so much yet been so confused by diapers: how can such a small diaper absorb so much liquid and “hold it” there until the diaper is removed. My daughter has sometimes... produced diapers that weigh almost a kilo but without a mess! Please help me!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxihezu"
],
"text": [
"Inside a diaper is a material called Super Absorbent Polymer or SAP. This is a powder mixed into a cotton cushioning lining throughout the absorbent part of the diaper. When SAP encounters a liquid, it grabs onto it and becomes a gel, holding the liquid in a matrix of carbon chains. It’s the same material that’s used to make instant snow"
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
holmfx
|
How do computers randomise/shuffle?
|
I don’t understand how an algorithm can be truly random
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxijd19",
"fxijvzp"
],
"text": [
"That’s the thing - it can’t. Computers are, by design, not random. Everything that you do on a computer is represented as data, and that data is stored physically as ones and zeroes, representing an electrical switch in either the on (1) or off (0) position. With enough of these switches, you can store information as a stack of these switches, and read it by translating the ones and zeroes into something that we can understand, like basic English. This is a painfully simplified version, but the important part here is that there is, 100%, no randomness here. If there were, the data you want to store or read would be corrupted, and therefore lost. Computers get around this by making incredibly complicated algorithms that take a starting variable, run it through a mathematical gauntlet, and then display the new result as the “random” number. An example of this would be rolling a dice for 1-6 in a gambling video game. Instead of running a physics simulation to determine how the dice lands, a computer will grab a random number from somewhere on the system. This is ideally a number that can change a lot over time, like the players current score added to the current time. That initial variable is then put into an algorithm, usually a long one that is likely to change the variable significantly, without reproducing the same numbers over and over. Then, this number is divided and rounded down until it’s a number between 1-6, which is then displayed to you as your result. This is usually how RNG is programmed, but here’s the thing: if you know what the algorithm is or how it works, and you can predict or manipulate the starting variable, you *can predict every time* what the “random” number will be, with perfect accuracy. A famous example of bad RNG would be the a Fire Emblem game for the Gameboy Advance. Instead of an algorithm or some kind of generator to create random numbers, it literally has a list of numbers that it goes down, one by one, every time something “random” needs to happen. If you know the table, you can use useless actions to burn through the low numbers or make your enemies use them, and then attack when the large numbers are next on the list. There are quite a few videos that explain this way better than I can, go look up RNG on YouTube. Edit: I love it when a comment spurs a bunch of good discussion. Just a reminder that my explanation is pretty quick and dirty, I skipped over A LOT in this explanation. Computerized RNG is a fascinating topic.",
"Computers don't actually use true randomness. They use an algorithm which is actually completely deterministic, but *looks* random, called a pseudorandom number generator, or PRNG. A PRNG takes an inital value, called a seed, and then derives an infinite sequence of values from that initial value. Because PRNGs are deterministic, reusing the same seed results in the same sequence. Let's say you have a PRNG, and use zero as your seed, then generate 5 values: 10, 0, 1, 99, 24. After that, you forget the values and start over, seeding with zero again. You'll get 10, 0, 1, 99, and 24 again, because those 5 random looking values were deterministically derived from the seed. In order to generate a different set of values, you have to use a different seed. One of the easiest ways to do this is just to use the current time as the seed. This is computer time, not clock time. Computers measure time by counting the number of seconds passed since Jan 1, 1970. Because this number is constantly increasing, PRNGs seeded with the current time will constantly generate new pseudorandom sets."
],
"score": [
30,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
hotvh6
|
How does keyboards in computers get values?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxk06hj",
"fxjzsjv"
],
"text": [
"It depends on the keyboard, but some use a lattice, where the rows or common and the columns are common. So when you press a key a certain column and row combo gets activated it can only be 1 option. The keyboard converts that into digital in a special way unique to the manufacturer software. This digital information gets sent through usb to the PC, where the driver interprets it and then sends it along to the rest of the computer to be further interpreted. This is only one method, and there are many, but most follow a similar method of : 1 determine which key is pressed 2 convert to digital 3 send to PC via USB 4 get interpreted and used by pc",
"Keyboards emit key press and key release events. The codes are roughly left to right, top to bottom, so the ESC key is code #1. It has nothing to do with the layout whatsoever, which is why an OS doesn't know if it's a QWERTY or AZERTY keyboard -- that's just paint over the keycaps. The keyboard itself sends the same codes anyway, so you have to tell the operating system what keyboard you have. So this key code, say #16 gets sent from the keyboard. Based on the configuration, the OS then translates that to an 'a', 'z', or something else. Let's say it's an 'a'. This means key with code #16 gets translated to position #97 in the ASCII table. If the shift key is being held, then it goes for the uppercase range instead, which gets you 'A' in position 65. Then in the ASCII table there's a [picture]( URL_0 ) of an \"a\" character in position 97. And all of that is basically the result of standards. The computer industry agreed on an alphabet, so everyone agrees that \"A\" is in position 65."
],
"score": [
6,
4
],
"text_urls": [
[],
[
"https://lh3.googleusercontent.com/proxy/XFjcCXUCZpXKd6qUKwIeG8cAXTh79fo-SEGV0RjJ-ilHxxr8y8wcQuNyhJTRL1Ye4gStlRLXnzAbRH7BnLLbhLLl74hdRsQXzrMxwphtKMmy9i3hRCm67IDc"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
hozjh7
|
before a commercial flight, why do the flight attendants make such a bid deal about everyone turning off large electronic devices and putting smaller ones in airplane mode. How does it affect the flight?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fxl0kcp",
"fxl0aml"
],
"text": [
"(Source: my brother, an aeronautical engineer) They don't. It's possible they used to in the past, but not any more. The main problem with big electronics is that they'll go flying around the cabin if there's an accident. They normally ask for you to turn them off and then store them.",
"Many electronics, including phones, emit RF radiation and RF noise. This RF can induce currents into the wiring of the airplane and can also interfere with microprocessors that control critical systems. Since takeoff and landing are the most accident prone portions of a flight, those are the most critical times for keeping devices that might emit RF radiation turned off."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
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