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85fe2l | How does old-school gameboy screens/calculators/digital watches display a picture without actually producing light? | The original gameboy required a light source to see what was on the screen, how exactly does that work? Shouldn't the screens output inherently be a light by itself? | Technology | explainlikeimfive | {
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"Paintings produce a picture without producing any light. They rely on ambient light around them for you to see it. a Gameboy's screen is an LCD just like your phone. Instead of a backlight in the background it uses a reflective surface that the ambient light bounces off of. Both screens have a film over them with a liquid crystal matrix on it, when electricity passes through a cell in the LCD matrix it changes from opaque to transparent or the other way around.",
"> Shouldn't the screens output inherently be a light by itself? No. LCD screens don't produce light inherently. Your monitor has a separate backlight that illuminates the pixels, which are tiny, translucent squares that can change what color and percentage of light they allow to pass. The monitor can change the color of the pixels without any illumination. But since your monitor is designed to be backlit, you can't really see it unless the backlight is on. Older monochrome LCD displays were designed with a light-colored material underneath to reflect ambient light so that the pixels would be visible. The only screens that produce their own light are CRTs, plasma displays, projectors, and OLED displays (where each pixel is its own light).",
"They produce images pretty much exactly like modern LCDs do. An LCD panel is, in effect, a wall covered in windows. On each window is a curtain that can be electronically opened and closed, either all the way or only partially. In a color LCD the glass used in each window is tinted either red, green or blue depending on its position. Most modern LCDs use a backlight, which means there is big light (or lights) on the other side of the wall. Any windows with the curtains open will allow the light through, so to display a dark blue image you'd close all the red and green curtains and open all the blue curtains part of the way. From a distance you'd simply see a blue image instead of tiny windows. Older LCDs (and those used in some low power small devices today) didn't use an artificial light source. Instead behind each window there was a mirror (well a reflective surface). If a curtain is open light from outside can enter the window and bounce back out from the mirror. If the curtain is closed no light is reflected and it's dark. The screens on calculators or digital watches (the ones with non-pixel shaped black digits) are typically doing it in a bit of a reverse manner - the light color is the reflector behind the LCD, while the black color is the curtain being closed. So if you have an 8 segment digit each segment is essentially a large shaped curtain - when power is sent to that curtain it closes shut (blocking the reflector and making a dark element) and if power is cut it swings open again."
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85h9gb | How are lumens in flashlights determined? | I have been looking up highpowered flashlights and I've found some with 120lumens to 10,000 lumens. All of which are saying they are "super bright", how can flashlights so differing in lumens all be superbright? Is it just marketing, am I wasting money on a 10,000 lumen flashlight? | Technology | explainlikeimfive | {
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"Lumens are a specific measurement done with meters. They are a measure of the total overall amount of light that comes out of the lamp, adjusted to how sensitive the human eye is. A typical \"100 watt\" house light bulb has at least about 1600 lumens. How wide or narrow the flash light beam is and how good the lens is will also matter. As will the honesty of a manufacturer and whether they sent it to an independent Testing Lab. \"Super bright\" is a totally subjective term."
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85hoba | Why is Google Pixel 2 XL phone charger 9V when the battery is only 3.7V? | Technology | explainlikeimfive | {
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"It all has to do with power. Wattage, to be specific. At 9V, the amperage is still around 2A, which translates to 18 watts ( Power = Amps * Volts ). The battery will still be charged with roughly 4.5 V, but the charging circuit now gets more power, allowing for more efficient charging. If the voltage it were being given were the usual USB 5V, it would need 3.6 amps ( 18 watts / 5 volts = 3.6 amps ), which would generate more heat in the delivery system. The reason for this is that greater currents at lower voltages creates more heat in smaller wires. Increase the voltage and you can more efficiently push power around. It's the same reason why the 14 kV medium-tension power lines are only about 1/2\" in diameter. At that voltage, they can carry a huge amount of power as compared to, say, a 277 V feeder cable of the same diameter. It's worth noting that the *apparent* charging voltage will be around 4.5 volts. It will be getting hit with thousands of spikes per second of 9 volts, which will average out to the proper charging voltage. Check out pulse-width-modulation, also known as switch-mode.",
"The charger is actually built into the phone. The thing you plug into 120/240 AC is a constant voltage power supply. The phone has a DC to DC converter which puts out a lower voltage which the charging circuit uses to charge the battery. They use 9V for the reason u/ProfessorAbbott said. It is a way of getting higher power without using a lot of current."
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85igo3 | How do prosthetic limbs stay in? | Technology | explainlikeimfive | {
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"They're not \"in\", they're \"on\". Prosthetics are something you wear & strap on, not something implanted in you.",
"I'm sure OP meant \"on.\" They often stay on by suction or by straps. There are some that are bone anchored, but I dont think that is that common.",
"Piggy backing here. Prosthetic limbs (or whatever these specific ones are called) that are able to be controlled by the wearer, how do these work? I've seen some that are some simple mechanical trap or squeeze parts. I am more referring to those that use more advances methods of control and what those methods are?",
"Assuming you mean 'on' . Straps and buckles.. they cast your existing limb and build on that. Attach Straps, measured for comfort etc.. it's a long fitting process done over a number of visits. It also has to be a v tight fit with no ventilation because a small amount of sweat helps to conduct the signal to the electrode. Someone else asked how they work and the answer wasn't very clear - suggested movement of what's left, which is kinda true but off the mark on the main.. Muscle contractions activate electrode sensors. So an arm may have 3 or 4 sensors (bicep, triceps, Deltoid etc). Activate your bicep the hand closes, activate triceps and it opens. Deltoid makes the wrist rotate. Rounding your shoulders will make the elbow bend (pulleys across the back) . etc etc. So it's not easy, you have to learn how to use each muscle independently - which is seriously tedious and difficult. with little to no experience you try and open the fist and it spasms, because you're using tricep and bicep together.. get stressed - spasm.. get tired - fucking spasming piece of shit arm!!! Source: born with left arm missing from above the elbow.. went through all this shit bunches of times before fucking it all off."
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85k0nh | How do companies like Facebook sell your data and why is it bad? | Technology | explainlikeimfive | {
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"Facebook uses so called WebBugs to track you across the web. They know virtually everything you do if you have a facebook cookie on your browser. Every time you visit URL_0 these companies know it: * Double Click * Facebook Social Plugins * Federated Media * Google Analytics * Quantcast * Rubicon * Torbit [Proof](http:// URL_0 /ekgtLxl) They are specialized in gathering browsing data and creating personal profiles of you. There are browser PlugIns that make these trackers visible and blockable for you. I highly recommend using one. Oh, and if you visited Facebook with your browser without deleting your cookies after, these trackers can link your browsing data directly to your name. --------------------------------------- **What you can do:** A good set of Add-Ons for firefox and chrome is in my opinion: * [Ghostery]( URL_3 ) / [Do Not Track Me]( URL_9 ) / [Disconnect]( URL_8 ) - They block WebBugs and Trackers * [NoScript]( URL_4 ) - Blocks Java Scripts you do not manually allow * [Better Privacy]( URL_13 ) - Deletes flash cookies that cannot be deleted otherwise * [uBlock Origin]( URL_5 ) - like AdBlock Plus, just better * [HTTPS Everywhere]( URL_12 ) - Secure Connection where available -------------------------------- **Why you should care:** The knowledge that one's actions could be monitored by the authorities leads to assimilation of your behaviour. Only by appearing non-threatening, boring and assimilated can you be sure that your actions cannot potentially be used against you in the future. The philosopher Michel Foucault addresses this phenomenon in [*Discipline and Punish*]( URL_6 ). Foucault uses Benthams panopticon to illustrate this issue. This panopticon is a tower in the center of a prison facility. When standing on top of the tower, you can see into all cells of the prison, albeit only one at the time. The prisoners have no way of knowing whether or not they are being scrutinised at a given moment. Despite the fact, that you can never monitor the behaviour of all prisoners completely, the possibility alone, that an inmate could be under surveillance at any given moment is sufficient to suppress unwanted behaviour. In our age, NSA, GCHQ, etc. take the place of this \"anonymous power\". > \"If the inmates are convicts, there is no danger of a plot, an attempt at collective escape, the planning of new crimes for the future, bad reciprocal influences; if they are patients, there is no danger of contagion; if they are madmen there is no risk of their committing violence upon one another; if they are schoolchildren, there is no copying, no noise, no chatter, no waste of time; if they are workers, there are no disorders, no theft, no coalitions, none of those distractions that slow down the rate of work, make it less perfect or cause accidents\" Foucault theorises, that the constant thread of surveillance alone is a way of exercising power. It leads to self-policing of the individuals of the scrutinised population. Thus, dissent and rebellion against power are suppressed in its earliest stages. Glenn Greenwald, the Guardian journalist who worked with Edward Snowden, held [an excellent TED Talk]( URL_10 ) on this issue. _______________________________ **Sources:** * As I said, browser Plugins make the trackers visible, so just check for yourselves. * Wikipedia article on [Web Bugs]( URL_14 ) * Articles discussing the issue [1]( URL_11 ) [2]( URL_7 ) [3]( URL_1 )",
"Facebook collects a lot of data about you. They either know or can figure out your age, political affiliations, brand loyalties, and so much more. They have two ways of monetizing this information. The first is to sell targeted advertisement. For instance, if I sell trucks, maybe I want to target my advertisement to people who are at least 30 and like my competitors truck pages. Those ads are worth more to me than an ad impression against someone who likes a lot of electric vehicle pages, or someone who is only 16 and won't be able to afford my product. The second way is to directly sell data about me, typically for an external advertising agencies. For instance, maybe a political party wants to know where their supporters are even if they aren't registered with the party. They may also want to correlate data about their constituents with occupation data so they know who is likely able to afford contributions to their parties."
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"https://addons.mozilla.org/en-US/firefox/addon/https-everywhere/",
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85lbvq | How was the first diamond cut? | I guess what I am asking is how was the first diamond cutter cut into a diamond cutter | Technology | explainlikeimfive | {
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"Very slowly. Just because it is used to cut/grind other materials doesn't mean that it itself can't be cut/ground/shaped/polished with other materials. It just means that the other materials will most likely wear down first. But if you use _enough_ of them. Think of it this way. I have a psycho future DeathRace 2000 driver with a car and I have a lineup of Euthanasia patients outside the hospital. Eventually, if I have enough victims, they will do enough damage at 80 mph to disable my car. But not before I've mowed through a few hundred of them.",
"> I guess what I am asking is how was the first diamond cutter cut into a diamond cutter Diamonds are not cut like with a knife, they are ground with abrasive materials. Typically this is done with a diamond abrasive which is basically just crushed up tiny diamond bits, which are far more common than gemstone sized diamonds. If you are finding diamonds you want to cut you already have a lot of potential abrasive compounds that you mined around it. So there was no \"diamond cutter cut into a diamond cutter\" because they aren't cut into shape.",
"Diamond may be hard, but it is a crystal. Like all crystals, it has cleavage planes, certain directions in which it is easier to break. Diamond isn't cut like cheese. It is snapped off along those cleavage planes, like breaking off a square from a chocolate bar.",
"From what I’ve learned a diamond can only be cut with another diamond. Is this untrue?"
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85llwf | Why does the lid of a ballpoint pen stop it drying out, despite there being a clear opening that sometimes you can even see the tip of the pen through. | Technology | explainlikeimfive | {
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"It is not to stop it from drying out. it is to stop it from leaving a mark on things you don't want to write on",
"It isn't meant to stop the pen from drying out, it's to help prevent leakage and accidental discharge. By which I mean, writing on the inside of your pocket and such. Fun side note: BIC says the hole itself is meant to prevent choking. If you (more likely a child) inhale the pen lid, the hole allows you to keep breathing even as the lid lodges in your airway."
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85n9sv | What's so special about AMD Ryzen CPUs? | I've noticed plenty of articles online discussing the various features of this type of professors. Can anyone explain the main differences as opposed to to Intel i5 or i7? | Technology | explainlikeimfive | {
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"AMD CPUs have always favored more cores, sacrificing performance per core for more cores to do work with. Contrast this with Intel, whose i5 and i7 CPUs are quad core, nothing more. However, per core, in general, Intel CPUs have much better performance. Historically, even with more cores, AMD CPUs perform worse than Intel equivalents, meaning that Intel had a pseudo-monopoly on the processor market. If you've ever taken an economics course, you know why monopolies are bad. AMD Ryzen CPUs aren't super special in the sense that they're some revolutionary technology. They are merely good enough to rival the newest Intel processors. This means that Intel now has pressure to push out better products again. People were complaining that there was very little difference between a 6th gen and 7th Gen Intel CPU. However, since AMDs Ryzen release, Intel's 8th gen CPU is once again a clear improvement on the 7th Gen. And that's why AMD Ryzen CPUs are special. They promote competition and innovation in the processor market.",
"AMD's Ryzen lineup has received a lot of positive press for being the first set of processors released in a long time that have been competitive. The main difference you will have to worry about from Intel's product, assuming choosing models of similar performance, will be motherboard compatibility",
"The two processors are pretty fundamentally different at an architectural level, AMD is doing some neat things, for example, they've changed how their caching works, building groups of 4 cores that share caches, with multiple clusters on higher core count CPUs. They're also now doing something similar to hyper-threading, called SMT, which is arguably better in some ways and used in some Intel server chips. The new Ryzen CPUs are system on a chip, which means they move a lot of the functions that *used* to be on the motherboard into the CPU, like PCI controllers, SATA, and even USB controllers, all of which allows for higher performance and lower power consumption. Overall, they're pretty neat, but the argument about whether they're \"better\" than Intel is kinda a silly one. Particularly if you're talking about gaming, when the performance of a specific game has more to do with whether the developer optimized for a specific CPU architecture or not, than with any inherent properties of the CPU. If you're doing application work, it's possible that some workloads might be inherently more suited to one CPU architecture than another. If you're doing a lot of video rendering for example, it's possible that one CPU or the other will have a slight advantage inherent to how the task *has* to be performed, rather than just an optimization thing like gaming. If you're gaming though, just watch for benchmarks on games you want to play, and pick a CPU that has reasonable performance at a reasonable price. It's unlikely that you could go too far wrong either way. If you're really curious about the internal details about the two architectures, the wikipedia articles aren't bad places to start, although they'll lead you into a lot of very technical details pretty quickly: URL_0 URL_1 URL_2 I included both Skylake and Coffee Lake as I understand Skylake to be the last time Intel introduced major structural changes rather than just a shrink of the process size."
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85nwu2 | Why do so many bootleg sports streaming websites display ads in a way which you need to turn on adblocker in order to use the site? Doesn't that lose them money? | Technology | explainlikeimfive | {
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"Because bootleg streaming sites don't care. They just pile on as many ads as they can to make some cash before they get shut down. They aren't in it for the long term.",
"Because the advertisers willing to be associated with an illegal streaming site aren’t going to abide by the best or most professional tactics. That’s all there is to it.",
"Only about a quarter of PC internet users have ad blockers. The site makes money on those that do not.",
"1. The ads themselves suck because typical advertisers do not want to advertise on illegal content sites because that is damaging to the brands they represent. So there are fewer ads available for these sites, and so the site is forced to allow the bad, scammy ones onto their site. 2. Ads don't actually pay that much money. These days traffic to illegal streaming sites has decreased due to increasingly viable legal alternatives. The site has a lot of temptation to make more money, and it's fairly easy to do by just adding more ads. They do this slowly and carefully, rolling back if this damages their business. But as long as they can make more money by adding more ads, they will do that because they're under pressure. 3. It's true that in the long term it's harmful for a site to show too many ads because it causes users to turn on ad blockers. Its an incorrect strategy for the sites as a collective. But, it's still the correct strategy for one individual site, given everyone else is doing it. If everyone else is doing it, then you might as well do it too, and you have a self fulfilling prophecy where all the sites put more and more ads. 4. Imagine you offer a site with fewer ads, in order to get more users. If you succeed and get tons of users you'll want to make lots of money because sooner or later you might get shut down and/or face legal fees. So you show more ads while you haven't been shut down."
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85ocp9 | why do some flashlights have a “fast flash” mode? | My flashlight I got from Costco a few days ago (1000W or whatever it’s called) has 3 light modes. Bright, dim, and flash where it just flashes very fast. I know someone flash lights have it as an SOS signal but mine just flashes constantly. | Technology | explainlikeimfive | {
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"IIRC, it's a strobe light mode to disorient someone who may be attacking you. My dad gave me one when I moved out on my own for the first time.",
"Strobes are much, much easier to spot in the dark. A flashing light catches the eye much better than a constant light. SOS signals are a gimmick, but a strobe is a great way to signal your location at night.",
"Greetings from /r/flashlight I've seen cops use strobe with a traffic wand to get more attention signaling cars, but the main idea is that it's supposed to disorient people. Some flashlights even have a dedicated strobe switch. It is my opinion that strobe isn't very effective for this purpose, and in a one-on-one defensive situation a light should be thought of as situational awareness only. Any time spent trying to disorient an attacker with a flashlight is almost certainly better spent running away or fighting using something more effective. I say this having stared into quite a few very powerful lights on strobe. So for the most part, I consider strobe a misfeature on a flashlight that's best hidden away, if included at all.",
"The solid beam is for when you need to see. The strobe is for when you need to be seen. The strobe function as a self defense tool is a complete joke. Please don't leave this thread thinking it isn't.",
"Strobe lights are incredibly disorienting because your brain is only getting flashes of the image in front of you, and your brain is constantly trying to connect the dots between the images you see but it doesn't really work given the frequency of a proper strobe light.",
"Another reason is as a bike light. My pocket flashlight is also my backup bicycle light. The flashing makes it more visible and saves a bit of battery life.",
"I've used on my left hand, out of the window while driving a van running to the hospital with an injured passenger to signal other cars to let me through, it worked wonders. Might also be illegal on any specific jurisdiction.",
"I was coming home late one night and came around the corner to a stalled car situation. One of the people was using the strobe to alert oncoming drivers to notice that something out of the ordinary was happening and slow down. It worked."
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85oefn | After recently seeing an article about laser technology uncovering a lost African city, why can't we use that technology to map the Paris Catacombs? | Technology | explainlikeimfive | {
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"[LIDAR] ( URL_0 ) works by flying a plane over the area you want to map and bouncing a scanning laser off the ground. The laser light can get enough back scatter through vegetation to map what's underneath. But lasers can't see through dirt, pavement, stone, or buildings. Some type of [geophysical imaging]( URL_1 ) might work, except that most signals will likely be disrupted by all the crap between the surface and the tunnels (old construction, foundations, sewers, pipes, wires...). Not to mention that an active ping - setting off a small subsurface explosion to catch echos, for example - has to be done in the midst of, and somehow filter out all the noise from, one of the world's major metropolitan areas.",
"Things blocking the ruins of lost African city: some plant life Things blocking the Paris Catacombs: the entire city of Paris.",
"Maybe I'm oversimplifying it, but why haven't we just you know...given someone paper and pencil and sent them to map it as they walked?",
"Couldn't the use muon particle imaging to do that like they used to discover new caverns in the pyramids?",
"The ELI5 answer: lasers can't go through the ground. See above for a much better explanation.",
"Certain types of light can penetrate a few inches of vegetation. Very few types of light can penetrate meters of stone.",
"why don't we map the paris catacombs using the same devices they're using to map the great pyramid?",
"There already are some good maps of the Paris Catacombs. However, if we tweak the question a bit to ask more generally about mapping subsurface human-made features, lidar is simply not able to do that from the air. Lidar bounces a laser off of objects below, using a a rotating or oscillating mirror in the sensor system to essentially \"spray the ground\" with the laser. The sensor measures the time it takes for the laser to return, and you have a distance to the ground. Combine with airborne GPS and possibly inertial measurement data to identify the sensor's position, and voila, you have a pretty good picture of the surface. Lidar can produce multiple returns of that laser, and because of this, can simultaneously map tree canopy and the ground. But, it can't see through solid objects, any more than a flashlight can illuminate your basement from on top of the roof. That said, there are mapping technologies that can map subsurface features. Sensors that use sound instead of light can map subsurface features. But, that's not likely a good fit for Paris. There's eons of building on top of building, plus a cacaphone of ambient ground noise that's going to make it impossible. Synthetic aperture radar can penetrate vegetation and dry soil to a few inches, but can't reach the depths of the catacombs. There's also a cool technique pioneered in the US city of Annapolis. Archaeologists seeking to map leveled buildings faced the challenge that there's a modern and fairly affluent city atop former structures. So, they asked nicely, and took measurements of remains of foundations that were exposed in people's modern cellars. By measuring lengths and angles of some remnant foundations, researchers were able to piece partial plans together to map a now superseded plan of the city.",
"What could you use to see the bones in a graveyard?",
"Interference. When we say map we really mean... well, a series of blips (scientific, right?). Usually blips signify a huge discovery if we a) already kind of know what we are looking for and b) if the blips form a shape that is clear and connected to other clearly-formed shapes (for example a blip that makes a square room leading to a bunch of blips making the shape of a road, etc.) Because the catacombs are in an area where so many other things underground will come up, the amount of interference probably blurs the results. I'm sure they did use this imaging in the beginning to see if they could find any clues, but it can't tell us much if it's just a jumble of blips all connecting with one another. Source: Archaeologist for 10 years",
"Having used LIDAR to map an indoor setting (and archaeological sites) in the recent past, it would certainly be possible to do so. In fact, one of the primary uses for the model of LIDAR I've used is to map the interior of mines in three dimensions. It is, however, somewhat of a pain in the neck to model areas where there are lots of \"nooks and crannies\" as the system creates 3D point clouds on a line of sight basis. LIDAR is essentially a really fancy laser rangefinder that simply measures many distances and angles to those distances at a high rate of speed - as a result if something is in the way of the laser you will get shadows in your model. You can account for this using multiple scanning locations and then stitching the resulting point clouds together, although this can take quite a bit of time. It's also a pain to georeference data taken inside large buildings or underground, although this can be done by linking areas inside your indoor area of interest to georeferenced points immediately outside.",
"And why can't we use it to find IEDs?",
"You can, but you have to go underground. Actually the French mapping Agency has experimental backpack embarked LiDAR that they use to map the sewers in high definition. To my knowledge it hasn't be used in the catacombs but it could be! will try to dig up a link, possibly in French though."
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85q3bf | Why is the breaking news about Facebook’s selling of user data such a big deal? | I am very confused. I was under the impression that there is no such thing as online privacy, that every click we make and page we view is tracked and bought and sold by various companies and entities. Furthermore, I thought that this fact was common knowledge. Datamining is nothing new. Targeted ads are nothing new. What is different about this story that has millions of people ready to burn down Facebook HQ? | Technology | explainlikeimfive | {
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"What Cambridge Analytica is alleged to have done goes way, way being simply collecting information that people willingly gave out online. It was how they did it, how they analyzed it and what they did with the results. If you were to take part in an online survey that asked you about your opinions on certain political issues, you wouldn't be surprised to find that this information was being collected to create an idea of what the current mood of the nation is. That's fine, although you might appreciate it if you were told that this information was being collected for this purpose, and you'd also hope that this information was anonymized. But suppose you did a \"Which *Lord of the Rings* character are you?\" survey, asking questions like, \"You're faced with a terrifying monster. Do you (a) run and hide; (b) call for help; (c) stand in front of it and yell, 'You shall not pass!'?\" Seems harmless, right. Just a bit of fun. Congratulations, you're GANDALF! But if the allegations are true, it is not just a bit of fun. Although the questions seem totally unconnected with anything political, CA claims to be able to analyze it and build up a very detailed psychological profile of you: your political beliefs, your hopes and fears, your race, your income -- everything about you, even very private stuff that you have never told anyone. Their boast, in fact, is that by doing this, they can wind up knowing more about you than you know yourself. In fact, they know you so well that they know what kind of propaganda you're most susceptible to, how you can be persuaded to change your mind, how you can be subtly manipulated without your being aware of it. Suddenly, whenever you go online, you see ads that you're not *consciously* interested in, but which are filtering through to your subconscious. These ads, by the way, are tailored to you personally. A few weeks later you answer the door to an opinion pollster. They ask you a few questions and record your answers on a tablet. What you don't realize is that the questions they ask you are again carefully selected to manipulate you personally -- using data collected online, they know to an accuracy of a block or two just what people in different areas think and believe. In fact, you don't even have to have been online at all: it's enough that your neighbours have, and there's a high degree of probability that you're similar to them. And to make this even more sinister, they're collecting information not just about you, but about your Facebook friends as well, even those who don't do any of these online \"surveys\". By looking at your friends, they can discover a great deal about you; and they can discover a great deal about your Facebook friends as well, simply going on the fact that they're friends with you. Now imagine that all this information is being given to just one political party, but not any others. You have no intention of voting for that party at all, but this same party now knows the best way to trick you into changing your mind. This is a *very* big deal. If the claims are even halfway true, CA has discovered a way to brainwash millions of people. By the way, this > we signed away all ownership of our data when we signed the user agreement isn't true. It's one of those conspiracy theorist claims that make the rounds whenever a social media site changes its TOS. You grant Facebook a licence to *use* your data and publish it online, because if you didn't, Facebook would be breaking the law every time it published one of your status updates. However, you still own your content, and you still have certain rights. One of those is the right not to have your data passed on to third parties without your informed consent.",
"I think a large part of it is that most people have never stopped to think about what Facebook etc. actually do with their data and are therefore shocked when they hear something like this. I'm with you, it seemed totally unsurprising to me and my aluminium foil deflector beanie.",
"CA found a way to use machine learning and data analysis to discover which states in the US would benefit from the most campaigning. Steve Bannon, the trump presidential campaign lead, got hold of this data. What would be the point of Trump doing rallies in big democratic areas such as California or New York? and to a certain extent, other areas too? None - these would have been lost causes - a waste of resources. What would be the talking points in these rallies? The talking points would speak directly to the voter in the swing states so that they would vote trump by using information given by CA. The democrats are pissed off that they did not use A.I. to help them win the election. They are even more pissed off now that the extent of the meddling was not Russia collusion which has been talked about a lot in the media but A.I curated in the UK.",
"The simplistic answer as I understand it is Cambridge Analytica had FB users take a voluntary survey. Anyone who did wasn't advised that CA would also gain access to all of their friend's data. Edit: the reason FB is in hot water is they initially said that doesn't constitute improperly accessing data on their platform"
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85qfyh | How do heat sinking missles work? | Technology | explainlikeimfive | {
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"There are sensor(s) on the head/tip of the missile (commonly called the \"[seeker]( URL_0 )\") are designed to see, analyze, and focus on very specific heat and light signatures of jet engines (or lets just say, \"bad guys\" because its a lot more complicated than just jet engines). See that glass looking dome? Yeah its in there. There are electronics on board the missile which continually fly the missile towards the location the seeker is telling it to go, primarily where the heat and light is. More recent variants of these missile incorporate extremely robust counter measures as well as multi-mode seekers which allow them additional ways to target the enemy. The specifics of these features are known only in broad strokes, for obvious reasons.",
"The aircraft tells the seeker head of the heatseeking missile to point at a certain direction, either by slaving it to the aircraft's radar or IR sensor after it's locked into something, or just by pointing straight ahead and steering the aircraft to the target. The missile will give a tone through the pilot's headset once it says, \"hey, I got something!\" The pilot fires the missile and inside the seekerhead a reflective cone shaped mirror spins inside trying to keep the heat source centered in the middle of the mirror. In the middle of the mirror is a photocell just like the type you see on a camera to detect the amount of light around you, except this one is tuned for the IR spectrum. The photo-resistor detects tiny changes in the heat signature away from the center of it and tells the missile's fins to adjust accordingly. More modern missiles work more like cameras and have computer models built into them; they actually look for the shape of an aircraft rather than just a point of heat. They can tell the difference between a flare dropped from an aircraft based on the UV light they emit and it's shape."
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85rhq4 | Can the whole internet have 0 ping at least in the future? | Technology | explainlikeimfive | {
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"No. Nothing, period, can travel faster than the speed of light. No matter how fast your data transfer speeds are, distance equals time. Even with unlimited bandwidth, latency is unavoidable. New York to London is 3500 miles. Even at the speed of light, that's over 18ms of travel time. Your minimum round trip ping would be 36ms.",
"No, signals can't move faster than the speed of light. That imposes a fundamental limit on the latency between any two points. For something like New York to Tokyo, that's around 35 milliseconds (if you use the most direct route through the arctic and don't do something crazy like bore through the middle of the Earth), so 70 milliseconds round trip is the best you can do between those two cities."
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85ti3s | How does an Organic-Matter Pollution Filtering bench, like the one most recently installed near Picadilly Circus in London, work to reduce Carbon-Dioxide as much as a small forest? | I saw an article about an organic matter bench in London that is supposed to absorb pollution and CO2, as much as a "Small Forest". Is something like this actually capable of combatin pollution as much as regular trees and plants? Link for reference: URL_0 | Technology | explainlikeimfive | {
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"sounds very questionable. this line: > Although only small, this device claims to have the same benefit of up to 275 real trees by filtering the air of up to 240 tonnes (265 tons) of carbon dioxide per year Note that it isn't saying it removes 265 tons of CO2. That would require 265 tons of matter to be removed from the site. It says it *filters* 265 tons, saying nothing about the efficiency of removal of any particulate. There's no way this moss would be as efficient at certain processes as a small forest. For one, the forest is simply going to produce more biomass, which means more CO2 is removed. The amount of CO2 removed from the air is directly proportional to the mass of the tree or moss added. As for other pollutants, that would require a ton of testing that has not been done.",
"Absorption is a function of surface area. By using moss and other algae’s that love CO2 and arranging them in a 3D space you can get about as much absorbing surface area as a small forest (in equivalent CO2 exchange capacity). Same way catalysts, or activated carbon work, reactions need space to happen, so the more space you have (in any direction) the easier reactions are."
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85tkel | Why have photocopiers not improved like digital photography? | Technology | explainlikeimfive | {
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"perhaps the copier was dirty, or maybe the source doc was blemished? a scanner can do upwards of 9600DPI for high end consumer units. that would produce a scan that would exceed the source detail of pretty much anything you could imagine... though it takes a lot of time to do, so most scanners are probably setup to scan at something much much lower."
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85vbsq | How does multi-core processing/parallel processing work | Technology | explainlikeimfive | {
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"Software (and Windows) usually work by breaking things down into smaller tasks, which can then be performed in parallel (at the same time) and thus on different processors. For example, the part of Microsoft Word that interfaces with the keyboard to \"grab\" what you type can be different from the part that does spellchecking in real time. Initially, processors worked \"faster\" by speeding up the electronics inside the processor; this is why the early processors were rated in mega-hertz (MHz), and faster was better. But at some point you just can't cram more transistors into smaller microchip areas; the heat given by the electricity flowing through the electronics begins to be a really big problem, so Intel, AMD, and the other chip manufacturers were forced to divide and conquer, as it were. So now, processors have 4, 8, 16, 32, or more \"cores\", with each core being an actual processor chip, and it's up to the operating system and the software to divide whatever task into multiple jobs that can be done at the same time. Software is programmed this way, from the start. In a game, the world geography, the physics emulation of how things fall and react, the AI scripts that drive the NPCs, the game interface (reacting to joystick or mouse movements and aiming), the network / LAN communication and synchronization, all of these can be done more or less in parallel.",
"Lets say you are making a meal. There are many tasks that must be completed before the meal is served. If you had one chef, and one waiter, the chef would have to do every task by himself, in order, before the waiter can serve the meal. But some tasks require waiting, such as water boiling. The chef needs to watch the water the whole time and do something once it boils, he can't just leave it alone. This is a single thread system. In a multi core system, while the chef waits for the water to boil, another chef can begin chopping vegetables, or cleaning dishes, or doing work instead of just stalling out and waiting. This is a multi thread system. On the multi thread system, the meal gets served faster since work can be done while the water is boiling. If there were only one chef, the whole system would stall out while waiting for a \"response\" from the water, which results in a poor performance or latency. EDIT: It is up to programmers to take a complicated task (making a meal), and break it into small independant tasks (chop vegetables). The better a programmer is at doing this, the better a task will run on a multi-thread / multi-core system. The new Vulcan graphics API does a really good job at dividing up tasks, and therefore multi core processers run it more efficiently."
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85vmjy | How do GPS apps like Google Maps know so accurately what traffic is like and where road work is happening? | Technology | explainlikeimfive | {
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"Google location tracking. More than a couple of people on a road, stationary, and it's a reasonable bet that the traffic is stationary. Google's location service is on so many phones nowadays it can be used to reliably track traffic information.",
"Google Maps knows because the same data is shared with Google's Waze app. Waze knows because users of the app are rewarded for supplying it. The other thing is that a significant portion of the people out there on the roads have Google Maps and/or Waze on their phones, tracking the movement of their vehicle.",
"For things like road work, you can get this information directly from state transportation departments. [Here are all of the APIs available for Washington State]( URL_0 ), for example. In addition to Highway Alerts (which tells you about closures and detours), it includes traffic flow data for major routes, border crossing times, mountain pass conditions, and a lot more. You can then layer additional user data (as described by others) on top of that for real-time updates of certain events.",
"Google uses your phones GPS and your location on the map even when you don't have maps open. As pretty much everyone has smartphone nowadays and at least half of all smartphone users (too lazy to check statistics) are on Android, that's a lots of real time data of users location, speed and movement direction plus probably tens or hundreds more of all kinds of telemetry data. Also Google collects this data over the years and they have their own data crunching software and machine learning algorithms. So if suddenly 20 android users are moving on the highway at 5 miles an hour when by Googles own data people normally move there at 60 miles an hour, it is not difficult for machine learning algorithm to determine that there must be a traffic jam. Also it can compare to other data points, for an example it knows that it is Friday and based on all the past data from all the android user speeds at particular parts on the road at particular times of the day on Friday, it can pull out the average and tell you that today around this time traffic is 45 minutes slower than on other working days. So that is my simplistic answer."
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85wr83 | Why electric kettle makes so much noise while heating water ? where does the noise come from? | Technology | explainlikeimfive | {
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"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [ELI5: Why is an electric kettle so noisy? ]( URL_8 ) ^(_4 comments_) 1. [ELI5: Why do kettles, saucepans on stoves make noise when waiting for boiling water? ]( URL_2 ) ^(_4 comments_) 1. [ELI5: Why do all kettles make the same noise when boiling? ]( URL_6 ) ^(_2 comments_) 1. [ELI5: Why does my kettle make a creaking noise when its heating up? ]( URL_7 ) ^(_1 comment_) 1. [ELI5: why do kettles make so much noise? ]( URL_0 ) ^(_2 comments_) 1. [ELI5: Why do electric kettles \"hiss\" when you turn them on? ]( URL_3 ) ^(_2 comments_) 1. [ELI5: Why are electric kettles so loud when they boil water? ]( URL_1 ) ^(_4 comments_) 1. [ELI5: Why does a covered pot of water or tea kettle make more noise right before it boils, than when it's actually boiling? ]( URL_5 ) ^(_1 comment_) 1. [ELI5: The noise when heating water, but before it boils ]( URL_4 ) ^(_4 comments_)"
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"https://www.reddit.com/r/explainlikeimfive/comments/3nwna2/eli5_why_do_electric_kettles_hiss_when_you_turn/",
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85ypbe | What is 5g and how is it different from former 4g lte etc? | Technology | explainlikeimfive | {
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"If we think radio waves as sound, the previous generations were like putting one big speaker in the middle of your house to play back music for everyone. The music naturally doesn't reach every corner of the house as some walls might be thin and others might be thicker. When moving about in the house, you might not hear the music at all if you went to the cellar for example. 5G is like being able to have the big speaker and then putting smaller speakers in the rooms where the big speaker can't be heard loud enough.",
"This is kind of hard to ELI5, but I'll give it a shot. A 5g internet connection is the combination of a bunch of 4g internet connections. Let's say John's computer is connected to Sally's computer through one wire called 4g. 5g is a bunch of 4g wires merged into one wire. This makes 5g a lot faster than 4g."
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85zjd7 | What do video driver updates actually "update?" How are Nvidia and AMD able to constantly provide improved performance in games? Where are they pulling these improvements from? | Technology | explainlikeimfive | {
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"Hardware offers you basic operations. You combine these operations in the software to render game for example. The software uses algorithms. Some algorithms are simpler, for example, it might take 10 hours to implement/test properly but gives you 7/10 on some benchmark. To get 9/10, it might need 50 additional hours of work. When the project starts, you've lots of things to implement but limited resources (headcount/time). So, you go for low hanging fruits. A thing which gives you a big chunk of performance for relatively less work. It does not make sense to put in everything complex in the first version and go over your time budget. The project might get axed and may never see the next version! So, engineers make safe bets. When a project is launched, in next several versions, algorithms are improved, the bugs found (based on collecting user feedback, usage metrics etc...) are fixed. Now, when there is not much else to do during the release of next version. I might go for putting in 50 hours of additional work to implement a complex algorithm to get you last remaining drops of performance from the underlying hardware. That's just one side. Research papers are published - new methods are discovered to do the same thing in more efficient manner, resulting in freed up hardware which might mean more performance.",
"The hardware doesn't change -- it's a piece of metal and silicon inside of a computer. It's what people do with that hardware that matters. Many of these updates help use the hardware more efficiently. A graphics card, when it comes out, might only be able to run at 60% efficiency. But then some software developer says \"AH HA! I found a way to make it run at 70% efficiency!\" And that gets pushed out on newer updates. There are also things like security and hardware management (fans, cooling, etc.) improvements."
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861f6v | Why haven't we been able to recreate the way fish gills pull oxygen put of water so that we can dive without tanks? | Technology | explainlikeimfive | {
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"text": [
"Because humans need a **lot** more oxygen than fish (we're much larger, and warm-blooded). Water doesn't hold enough oxygen to keep us alive if we were to mimic fish gills."
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861hox | how do police recover deleted info | Technology | explainlikeimfive | {
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"When you \"delete\" something it is not erased, that would take too much work. Your computer or phone will simply mark that space as \"empty\". Eventually some other data will be written into the \"empty\" space, but until then the data is still there and can still be recovered by tools made for that task. If you are unlucky or do not use that much space it can take a while until your data is truly gone."
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862xyx | diverting an asteroid using paint. | Saw on a gizmodo article, there is a asteroid projected to hit earth in 2135. One of the ways in which they looking at diverting the asteroid is painting it. Many questions here. What kind of paint? Something you can pick up at your local Sherwin Williams? How would simply painting it (according to article only one side) make enough difference to push it off course? Would paint dry in the nothingness of space? Does that even matter? | Technology | explainlikeimfive | {
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"> What kind of paint? Something you can pick up at your local Sherwin Williams? Conceptually yes, but of course they would actually use some specially formulated space paint. > How would simply painting it (according to article only one side) make enough difference to push it off course? The sun blasts out charged particles all the time and that pressure (including just the momentum of light) nudges the asteroids a tiny amount. By changing the surface exposed to the sun the path of the object can gradually be changed. Of course this isn't very much in the short term but even a tiny push lasting years and at the start of a millions of mile journey can mean a drastic change in its course. > Would paint dry in the nothingness of space? It would be weird, hence the space paint. Water content in a liquid would immediately start to boil away in a vacuum as well as freeze which would leave a weird surface which probably isn't what they want. And strictly speaking most paint doesn't \"dry\" so much as \"cure\"; you don't want the paint on your walls to be water-soluble, right?",
"The natural asteroid material is very absorptive (close to a black body) meaning that the large majority of incident light is absorbed. This light has a certain amount of momentum associated with it which acts to gradually alter the path of the asteroid itself. By painting it, or part of it, white, we cause the incident light to be reflected rather than absorbed. This change the nature of the momentum transfer, and therefore the trajectory of the asteroid will be different. The size of this momentum change will be very small, but on the scale of an asteroid's orbit even a very small change can easily be enough to make it miss the earth."
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866tbe | Why is google so much better than other search engines? Why have other search engines not been able to replicate google's search accuracy? | Technology | explainlikeimfive | {
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"In short, it's not. Something like Bing could return results just as good as Google's. Google does have a bit of a tiny advantage because their data is connected to so many other places now, but something like Bing with microsoft's data could definitely be comparable. What we've got here is more a case of Google being grandfathered in. Back in the older days of dial up the internet was much slower. This meant that search pages like Yahoo with their pictures and weather and news often took significant time to load. Google, on the other hand, still had the very simple search bar, so it loaded very quickly. This gave it the appearance of being much faster and more responsive with its searches, and that sentiment got impressed into us so we still carry that connection, despite internet speed no longer being a factor in search quality.",
"I wouldn't say Google is, quote, so much better. The competition is pretty good, although that's my subjective opinion based on the things I value. Privacy, simplicity, not selling my search queries to Facebook. Take URL_0 , very good at all those things.",
"What made Google's name was their PageRank algorithm. Basically, it ranks pages based on how many other pages of high value link to them. So an article on an old painting, for example, might display as number one if numerous reputable magazines and museums have linked to that same article previously. Google refined their algorithm and websites refined how their sites read and look over the years, but that's essentially what makes it tick. Back in the day Yahoo used to be a literal directory of links out to various categories of site. It had a search box too, but it maintained a huge directory of websites for people to browse through. Google allowed everything to be searchable by the user.",
"Can’t really say how true this still is, but at least when it launched Google really *was* better. The concept behind its algorithm seems pretty obvious now, but it was something of a search revolution at the time. Prior to Google, search engines indexed and ranked documents only in the context of their contents, isolated from the rest of the Web. So a crawler would read in a document and say, “this document is about caterpillars, I’ll return it when someone searches about caterpillars.” Which is fine until you have two documents about caterpillars; how do you choose which to return (or, more accurately, in which order do you return them)? Google’s breakthrough was to look at how the rest of the Web viewed that document. The basic premise is that people tend to link to what they feel is the best document for whatever purpose they’re linking it, so you can gauge the quality of content by how many people link to it (and the words they use while doing so). So you’ve got your two documents about caterpillars. One of them has two links: “my son’s webpage” and “what even is this.” The other document has thousands of links to it, with text like “lots of good information about caterpillars.” Google’s algorithm would rank the second page much higher, because both the number of links and the text of those links indicate that it’s *better* content about caterpillars. In short, Google’s algorithm gave them a way to not just say, “this page is about caterpillars,” but to judge *how much* it was about caterpillars relative to other pages. That, along with the page speed that was mentioned, was their major competitive advantage in the beginning (the paper in which Brin and Page laid out their original algorithm is available online, but the title escapes me). In the current search engine landscape, of course, everyone does that. I honestly don’t know if Google still has any kind of advantage because it’s been awhile since I’ve really had to care about how search engines work. (Historical side note: Yahoo!, at its inception, was actually a human-curated index. People had to sit down, review each page, and decide what it pertained to. I’m not sure when they switched, but I wouldn’t be surprised if they still used human indexing when Google hit the scene. Just as a basis of comparison.)"
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867j6j | What is the difference between a monitors refresh rate and its response time? | Technology | explainlikeimfive | {
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"Refresh rate is measured in a unit called 'hertz'. Hertz (Hz) is the frequency per second that an electrical signal oscilates. When it comes to monitors, the refresh rate is measured by how many times the screen will refresh per second. Most monitors will refresh at a rate of least 60Hz, which means that the screen will be redrawn 60 times every second. The higher the refresh rate the more often the screen refreshes. Higher refresh rates are helpful in situations where the screen is displaying content that is moving quickly. A common example would be a first person shooter game, like Call of Duty. This can lead to image anomalies, like tearing. Tearing occurs when the computer's video card is sending data to the monitor faster than the monitor can refresh. You wind up with cases where parts of the screen are displaying part of one frame, while another part of the screen are displaying a part of a different frame. See the link for an example of tearing. URL_0 Response time is the measurement of the time it takes between when the monitor's circuit board receives an image update from the computer and when that image is drawn on the display. The lower the response time, the less you have to worry about a phenomenon known as \"ghosting\". Ghosting occurs when the monitor is not fast enough to keep up with the information coming from the computer. You wind up with a situation where the monitor will be displaying portions of multiple image frames. It will appear as though the screen is trying to show two or more different images at the same time. This reduces image fidelity and is generally undesirable in any type of gaming or video playback. It tends to occur most in situations like when you are playing a game and turn around really fast. See the link for an example of ghosting. URL_1 Generally, this isn't as much of an issue today as it was about 10 years ago when LCD monitors were first coming to market. Back then it wasn't unusual to have monitors featuring a 12-15 millisecond (ms) response time. Couple that with a 50-60 Hz refresh rate and you have a recipe for very poor picture quality in fast moving scenes. Today though, most monitors' response times are 5 ms or less and refresh rates are 60-75 Hz or higher, sometimes as high as 240 Hz. There are specialized technologies in many computer monitors today that take this one step further. G-Sync (from NVidia) and Freesync (typically used by AMD) both force the monitor to communicate with the computer's graphics card so that they synchronize delivery of image data with the monitor's refresh rate. This virtually eliminates ghosting, tearing and other undesireable image anomalies."
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86ck4j | Why diesel engine cannot run on petrol? | And vice versa - petrol engine on oil? Basic princple of operation is the same for both - burn liquid fuel, so what makes difference? | Technology | explainlikeimfive | {
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"Diesel engines ignite the fuel with a different process than petrol. In a diesel engine, it's the compression of the fuel above a certain pressure that causes a spontaneous ignition. Normal petrol is formulated to resist that effect, because engines designed for it use spark plugs to create electrical arcs that ignite the fuel. Putting one into the other would cause either nothing to happen (diesel would not even start), or would potentially damage the engine because the fuel would ignite when it's not supposed to.",
"The only thing the other comments didn't mention is the lubricating function of diesel. Gasoline does not smear the engine like diesel does. So if you put gasoline in a diesel engine, you risk jamming it. That's why you should always call a mechanic service when you tank the wrong fuel and don't start your car!"
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86dm2q | Why so many positive results come from testing stem cells on animals, but aren't offered to people yet. | I just read another post about stem cells 'curing' alcoholism on mice. There's so many other cases of stem cells, such as regenerating lost limbs. Why aren't such advanced treatments offered to people yet? If the stem cells are actually acquired inhumanely, then how do we have them to test on animals? | Technology | explainlikeimfive | {
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"Because more often than not, those articles you read are very overblown. What you usually get Scientist: Hey, using X might help us detect Y, which in turn can help us when dealing with cancer ABC. Of course, we are only in the early stages of testing and more rigorous tests might show the effect of X is not significant or even has severe side-effects that limits its application. News article: X destroys cancer. Most journalists do not have a scientific education and often do not understand the small but important details in published papers. Additionally, they need to write an interesting article that gets people to click on it, which often means having to overexaggerate what is happening cause nobody is going to click on what is really happening.",
"The thing about mice, they're all the same (the ones that are used in studies). It's hard to get uniform people, so you can remove a lot of variance when you test on mice. The problem happens when they realize that mice aren't people, so not everything that is learned from mice can be applied to people. Or maybe the specific procedure may be ethically difficult to test on people."
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86dx3u | What is Gradient Boosting, and how can it be used? | I've been looking at some machine learning concepts and stumbled across gradient boosting. However, I don't really understand it and I can't find a simple enough explanation on what it provides, and more importantly what problems I could use it as a solution for. Reddit, please help me make this complex thing simple so that my poor brain may better understand it. | Technology | explainlikeimfive | {
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"(The following is a bit of an ELI5ization of the following blog post: URL_0 ) So I have a friend named Arthur who is pretty ok at guessing people's ages. However, I've noticed a pattern where he guesses a little bit high (on average 3 years) for men and equally a bit low for women. So if you want a good estimate of how old a person is, ask Arthur first, but then ask me and I'll tell you how much to adjust Arthur's prediction. Arthur says she's 19, I say +3, you add those up and predict 22. But note that I'm not an age predictor... I'm an *Arthur-being-wrong* predictor. If you could find someone who's well trained at being a *me-being-wrong* predictor, you could do even better. Claire notices that my estimates should be adjusted +3 for Asian people and -2 for everyone else, so now if you ask Claire you can get an even better estimate 19+3-2. You can see how this is an ensemble -- the more of us the better (up to a point, of course)! -- but not the usual kind, it's not a bunch of people all guessing ages and taking an average. Rather, the first person learns to predict ages and each subsequent person learns to predict how far off the previous person is. To get your answer, you just sum our predictions. (And unlike my story above, the first regressor doesn't even have to be very good; just better than chance.) Anyway, that's boosting; gradient boosting is a particular way of training ensembles like the above using gradient descent, which has the nice property that it can minimize a lot of different senses of \"being wrong\" and therefore optimize for various kinds of problems. Like this is a regression problem, but you could imagine a classification problem (Arthur+me+Claire+others trying to guess people's occupations), and the optimization algorithm would stay the same even though that's a different sense of being-wrong."
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86htjh | How do cell phone towers route calls? Is it the same way the internet routes to different IP addresses? | Technology | explainlikeimfive | {
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"Cell phone towers don't route call. They just provide physical medium for accessing the network. A node called MSC (Mobile switching center) routes the call. You can imagine towers a like, wifi routers when you are using Skype. Wifi Router = Towers, MSC = Skype server"
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86j8kn | What is IP routing and should I have it on? | I’ve been looking everywhere to try and figure out what the hell it is, but I can only find articles with a bunch of networking jargon. I’ve been reading around for like 45 minutes but I STILL have no clue as to what it is. | Technology | explainlikeimfive | {
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"IP routing is how data finds its way from your computer to a server on the other end of the world and back. Basically, the data is broken into small packets, and for each of that packet, a \"router\" (on your local networks that's typically the box that also produces the wifi) is asked \"please deliver this packet\", and it looks at the target address and knows which of its network connections will bring the network closer to that address. It sends it there, and another router in that network will pick it up because it knows where to forward it. Inside an ISP's network there are huge, powerful routers that connect dozens of networks and can process millions of packets each second. But it's unclear what you mean with \"should I have it on\". Is there a configuration option that says \"IP routing\"? That could mean to enable your computer to act itself as a router. In most cases you don't want that. If your internet setup works, don't change that configuration. But without \"IP routing\" *in general*, you cannot have any kind of internet access."
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86jhbn | Why does better quality music( 320 Kbps, and so on) occupy more digital memory? | Since I started using Spotify Premium I noticed that if you choose to stream music with "extreme" quality, it fills up my phone's memory much more quickly, and so I'm curious as to why that is. | Technology | explainlikeimfive | {
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"Just like with an image, higher resolution = bigger file size. The bit rate of an audio file (ie 320 Kbps) is essentially the resolution of the song. Higher bit rates = more bits of data per second of music. It has absolutely nothing to do with musical notes like one of the previous answers suggests.",
"The bit is a unit of digital storage. 8 bits are in a byte, 1024 bytes are a kilobyte, 1024 kilobytes are a megabyte and so on. So it should stand to reason why the higher quality music uses more space. The clue is in the name. 320Kbps (kilobits per second) means literally 320,000 bits per second. So naturally that's going to use up storage three times faster than 96Kbps. 320Kbps means that there can be many more digital 'snapshots' (or samples) of the sound wave per second than you can get with 96Kbps, so you get better quality, clearer high end audio (fizzing cymbals and so on), various other things that lower bitrates can miss."
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86ksrn | What is the point of Chase Pay? What is JP Morgan saving by setting up Chase Pay with merchants, but still using Visa cards as the network? | Technology | explainlikeimfive | {
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"TL; DR: It's not a cost-savings move; it's a strategic hedge to maintain customer share in a mobile-first economy. The point of Chase Pay has nothing to do with cost savings. It has to do with the push towards mobile banking and away from a physical credit card. In fact, development likely increases their costs. Many economies have moved towards the phone as the basis for banking and payments (and away from the wallet). The large Asian economies (China, Japan, South Korea) tend to be cited but African countries have similar trends, with some differences, as making the phone your banking center. You can send money, borrow money, make payments, etc. all from your phone. In Kenya, for example, phones have replaced banks... which means VODAFONE is the \"bank\" ( URL_0 ). It is assumed that a similar thing will happen in the United States. And the banks don't want to be taken out of the consumer market for financial services. So they have to compete with Google, Apple, Verizon and all the other banks for an app to at least be competitive as the switch occurs. As for why move towards mobile banking has advantages over physical credit cards. Harder to duplicate, easily handle 2FA, less likely to be forgotten at the store, etc."
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86n97z | Why do parts of the world use CDMA and others use GMA | Is there a reason that there isn't widespread adoption of one and not the other? edit: I meant GSM | Technology | explainlikeimfive | {
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"I assume GMA should be GSM, GSM is a TDMA system. CDMA and TDMA is whay to share a radio channel between multiple uses The simple explanation is that when digital 2G mobile phone system development started in the 1980 different companies had indifferent ideas how it should be done. The Europén GSM become dominant and all 4G system today are descendentens of it. Some handset are compatible with CDMA2000 system because there are large deployment of them primary in the USA and it is expensive and take time to replace the the towers. So to get good coverage som phones can still use CDMA2000 In the US Qalacom developed a CSMA system IS-95 or cdmaOne Digital AMPS was another north american system the was developed it was a TMDA system like GSM buy Bell Labs So the US and Canadian government did not intervene to try to have a common system. The lest the markes solve the problem is the US way. The areas was also dominated by a few large companies In Europe in 1983 the development started as a by the coordinating body of telekommunikation and in 1987 countries signed a agreement that GSM should be the system used for next generation mobile phone system. Europe are multiple small market with the existing cable base phone system operated by governmental agency. There existed private owned cell phone operators. The system also resulted in a system where hand sets was compatible so you could change operators. That is important for a consumer but not what a large telecom company like. So enforce a single standard resulted in a system developer per county. It is also more important to have compatibility between countries in Europe compared to North America where the countries as the size of states. South Korea and Japan also had their own standards. So the North American companies primary started to deploys the locally developed system. The fact that hand set was locked to network was a advantage to the so they could keep customers. The disadvantage is that is a was property system by one developer. The result is that GSM become the system the the rest of the world primary adapted as there was multiple vendors and you don't get locked in to a single vendor. That was not the same problem for large North American telecom companies as there size resulted in good bargaining position If you look at URL_0 that have a graph of system 2003-2007 you will notice that GSM is the international defacto standard with 80% in 2007 and 2014 is was When 3G system started to be developed whare was the old GMS that become the 3GPP collaboration was the dominate one wit US, Japanese, Chinese joining. The UMTS standard that was the result used CDMA as one way to share a frequency. For 4G and later it start to become one system. 4G LTE is the market names that is a global standard There are still some system that use the cdmaOne base 3G system called CDMA2000 but there is no new incompatible 4G variant and 4G LTE is used. So phones for the network that started to use CDMA2000 still have compatible cellphones so the legacy part of the network can be used. The operators done have the same coverage with 4G. Another factor is not only the system but what frequency is used. Different countries give different frequency band to mobile phones. So a cell phone might only be able to use some bands. So a cellphone might not work even if it is the same system."
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86ow0q | What's the difference between one day (single use) contact lenses and regular lenses? | What makes the single uses lenses single use. Why can they not be used multiple times like other contact lenses? | Technology | explainlikeimfive | {
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"One day lenses are much thinner and less durable, however since you wear a new pair every day they're usually more sanitary, can't develop buildup that can scratch your eyes, and generally easier for the wearer. Biweeklys and monthlys are much sturdier, but degrade over the lifespan of the lens. They also require a lot more care than daylies. You're supposed to rinse them for 5 seconds on each side with solution and let them sit in the contact solution for 8 hours, which can be a lot of work. Most people I've heard don't rinse their contacts, just soak them. Also, everyone's eyes work differently - some people can use the biweeklys for over a month, while other people's contacts degrade quicker. This can lead to either just living with worse eyesight or quicker replacement. Wearing contacts longer than their recommended use period can cause microscratches on the cornea from tiny amounts of buildup. It can be done, of course, but it isn't great for the eye.",
"Went on a date recently with a woman (monthly wearer) who called me out on wearing daily lenses because of the extra waste it creates. Of all the deal breakers...",
"I do not wear contacts, but when someone explained it to me what I understood was: that the daily ones are the softest, bend easily, are more comfortable and easy to insert (I'm not sure about this part), but not very durable. Contacts meant for longer use are more firm and thus more durable. There are also contacts that are meant to last a month. My friend who explained it to me found them uncomfortable in general, and only wore them when necessary, (on days when he had to perform with his violin)."
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86r8fv | Filmmakers/photographers, why pay hundreds of dollars for a light, LED or tungsten when you can buy a 40$ LED light that does the same thing? | Technology | explainlikeimfive | {
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"The issue is color temperature - and, specifically, Color Rendition - how color shows up on camera, and how well they illuminate colored objects. A true tungsten light is just a very hot piece of metal. It outputs every color of light, in a smooth gradient, with more oranges and reds in ordinary ones, and more blue in hotter halogen globes. Other light sources only imitate this. Cheap 'white' LEDS could do this with a bright blue LED and a simple yellow phosphor that absorbs some of that blue light and output some yellow. While this looks white to our eyes, it is really just some yellow and blue light. If you put something red under such a light, it will appear black, as there is no red light there. Same thing with a green object. But a yellow or blue object will be overbright, as there is too much yellow and blue there. We say this LED has a poor 'color rendering index', or CRI. LEDs improve the CRI by making that yellow phosphor a mix of different phosphors, that produce many different colors of light - from deep reds through to cyan. This mix of light is a better substitute for that smooth mixture of all the colors of a tungsten light. But there are still gaps in the light curve, because an individual phosphor emits a very narrow band of color. It will also have a gap just below blue, will have too much of the light made by the blue LED, and none of the violets. The more of this you do, the less efficient your LED is. Turning blue into deep red throws away lots of your LEDs energy, so a normal LED doesn't have any deep red phophors. Making cyans also wastes power, so normal ones just let the excess of blue take care of it. But this means there are some colors that don't show up well, but that's OK for house lighting. But this is no good for camera work. For that you need LEDs made with lots of phosphors, phosphors that absorb most of that blue light. Or even LEDs that use a near-ultraviolet LED, and produce all of the visible light with phosphors. This gives great color rendition, but is less efficient. LEDS with really good color rendition are not made in the same huge numbers as normal white LEDs, so they are much more expensive. So lights made with them are going to be a lot more expensive.",
"Former magazine/fashion photographer/camera equipment reviewer/current hobbyist here: I would recommend just buying the cheap one if you don’t even know what the expensive ones do. I’m not trying to be snarky but it’s the ONLY way you’re going to learn exactly why you need to spend so much for a light. Lights for photography are expensive because they *do* things that other lights do not. I would have gladly paid 5 times the price for my several thousand dollar lights because they saved me at least that much in the specific things I did. You don’t do anything, so you do not need a light that does anything. Asking why a $500 light is better than a $20 light is like asking why a $50 crow bar costs more than a $5 steel rod even if they do the exact same thing. Then asking if a $200 table saw would be better than the $50 crow bar. You buy a light to solve a problem not to spend money. If you’re just spending money you are already buying the wrong thing. Does that make sense? Nobody can tell you what tool you need to buy or which would be best at the hardware store if they don’t know exactly what *project* you’re using it for. Once you buy the junk, use it to make content, and look at a [color chart]( URL_0 ) of it’s results you’ll have your starting point.",
"Another thing beyond capabilities that the cheaper lights may not have is that the expensive lights offer reliability and support on another level. Suppose for example you are shooting on a RED Weapon camera kitted out with all the bells and whistles that comes to around a quarter of a million dollars. You are on location and burning in excess of a million dollars a day. Every minute counts; what lighting panel do you want? The one which is $400 and is extensively tested to work with your camera and equipment, where if you have a problem you can call directly to an expert engineer and also can next-day ship a replacement anywhere in the world? Or do you want the $40 panel which is \"pretty good\"? The high end panels aren't really for the average Joe but they have their place.",
"A likely difference between panels made for photography is the ability to change the color temperature of the light. It might also be hard to know the temperature the cheep light will have and it might not be the same for different panel. Another difference might be how the light is distributed if it is even. So if you might be able to find cheap one that works find but a question is how hard it is to find and test them. The construction quality is likely different a product designed for fixed installation will not survive being handled the same way as one that is designed to be moved. The mounting options that exist on one for photography is likely not the same as the one for installation. Light rating on cheep LED product from non name brands are often quite misleading. I would not trust the listing of some cheep panel you might find online."
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86rkbq | why it isn't common for films to leak early by staff somehow getting the file? | Technology | explainlikeimfive | {
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"The files are carefully controlled to prevent that happening, and it is identifiable where and who such a leaked file would have come from. Someone working on the film isn't likely to have access to the entire thing, just the part they work on. Generally speaking people don't want to ruin their lives by breaking their contracts, destroying their careers, and being sued into oblivion just to give people a free movie.",
"Even when special screening copies of films are given, they contain not only visual watermarking on them that often can be tracked back to who it was given to (those folks don’t want to get in trouble) but they also contain hidden tiny watermarking that could be 1 frame at a special spot in the film and only the company that prepared it knows exactly where to look for it. You wouldn’t ever be able to find it but once leaked the company can download it and determine who is to be held accountable. Due to this I think leaks are less common than say 10-15 years ago when people simply blurred the larger visible watermarks/identifying information.",
"When you're logged in as staff member X and download the movie to an external device id imagine some alarm bells would be triggered on the network.",
"I worked at a place where we had access to in production version. There are multiple layers of security, the physical film reels are in a temperature controlled vault where very few people have access to. And all the newer films are in digital form in huge storage array. While we can access them, including work in progress version that hasn't completed production. There are multiple layers of security, we work on computers that have all USB ports locked down so you can't plug in a USB drive. We had to VNC into a separate virtual machine to do our work. Also these original film files are huge. Transferring them anywhere out of the ordinary will probably raise a lot of warning in IT. If you try to re-encode them on the spot before transferring, it will create a strangely high amount of CPU usage which probably is being monitored as well. There are machines designed for transcoding that can do it really quick, but those machine also log everything they process, who ordered it, where it's going, etc. Lastly we all have to sign agreement before taking the job that if we leaked company property, we can be sued for lost profit, which will probably be some amount I can never even get close to repay in my lifetime.",
"The video files sent to the theater are encrypted. The projector itself decrypts the file as it is projecting. There is no interface by which the theater staff can access the unencrypted video file nor the encryption key. It is like a game console. You have the game console and you have the game disc, but you can't put the game disc into a computer and copy the game.",
"What would be the motive for doing so?",
"They've caught up and found ways to know exactly who leaked it. Another comment mentioned the watermark but I didn't see one mention that each Award Screener now has a specific watermark to each copy. So, if it makes it on the net early they know who did it. As for \"in the studio\" leaks, companies have tightened access and control. A guy used to be able to sneak a copy away to upload and there was plausible deniability due to the large group with access to it. Now it's down to a few people that have damages built in to contracts. If it leaks you all get boned. So, it rarely leaks now. Lower-budget movies still get leaks and some screeners still leak but nothing like the early 2000s.",
"Some films are scripted on airtight laptops/computers. IIRC, one of the Star Wars films had the script on a MacBook that had never been connected to the internet or had anything other than the charger plugged into it",
"They often do leak in other parts of the world. I watched a few movies on pirate dvd in China before the movies (actual movie, not dvd) were released in the US.",
"My brother works for a digital cinema mastering and localisation company (UK) the films they work on are encrypted at the end of the process and the cinemas have to request single-use keys to play them. Prevents anyone from copying the files and also prevents unauthorised screenings.",
"Most people are not thieves who are willing to blow up their careers for little gain. There is also a limited amount of people who have access to the finished product, and even fewer with the means to transfer that to another device. It is not like it is just sitting around a server, access wide open, no auditing with open usb ports to just copy it over.",
"Maybe because of respect to there job? Also i assume its mostly interesting and good payed i guess.",
"Source: Used to be a manager in a large UK chain cinema when they fully converted to digital and got rid of the projectionists (on the opening weekend of HP7 part 2 but that's another story) The film arrives on a hard drive to be uploaded to the server which then sends it out to the projector. The film file is encrypted and will not play on the projector unless a unique key file (KDM) specific to that film and projector, sent to the cinema separately via email is also uploaded to the projector. The KDMs are timed so they unlock at a certain date and time and will also have an expiry. The projector unencrypts the film on the fly each time it plays. Therefore if you don't have the film, the key AND the projector you can't play the film. The projectors are fucking massive and would definitely be missed. Edit: other people have weighed in about copy protection, I don't know a great deal about that side but the film file itself is shared with multiple cinemas (basically the hard drive goes on tour), I believe that the individual projector leaves a watermark on anything it plays for identification if someone videos the film on their phone or whatever.",
"Why would they risk their job for that? Would you leak your bank's info or your other secret information about your company if it's easily traceable to you?",
"Also: how big is a usual movie if you download it? It's been years since I did it, but I think I remember a longer film would be around 10GB, if it's high quality. Movies at cinemas are received as DCPs (Digital Cinema Packages). A film is usually well above 100GB (the last Star Wars was larger than 150), meaning most computers wouldn't even be able to play them.",
"I think the truth is more mundane. I worked on rec not national census project as a system admin. I had access to query all of the live databases for whatever I wanted. Guess what, I didn't bother. Partly because I like working in IT and wanted to keep doing it, but mistly I just could not be arsed. Sorry truth is usually very dull.",
"The files we have in the cinema are encrypted, and can only be viewed when the cinema has been sent a file from the distributor called the KDM. (Key Delivery Message) Detailed in the KDM is the file it unlocks, the server that it is unlocked on and the time period its unlocked for. Typically files unlock the day before release to give the cinema a chance to check and make sure it plays correctly. Most distributors send 1 KDM per server in the cinema (so if you've got 5 screens, you'll get 5 KDMs allowing you to play the film in any of the screens for that time period) with it unlocking for a couple months Disney however tend to send a renewal KDM each and every week.",
"Data Management Technician here! For one, when movies are sent to theatres, they are put on something called a DCP, a Digital Cinema Package, which is usually heavily encrypted and works almost like an online rental, in that you have a set number of plays or days that the movie can play before being wiped from the DCP or locked up again indefinitely. A girl I know who is a representative for a film society in my community tells me all the time about how studios will send out DCPs forgetting to unlock them or include the passkey. Secondly, yes, it's such a process to cut a film. I remember one of my first ever gigs as a data tech, I really wanted to impress the crew, so I prepared all of these proxies (smaller versions of the day's footage) and put them on these shuttle drives for the crew to playback in their hotel rooms at the end of the day. I thought it was a great idea since the camera team was always coming to me to check their focus or the Camera Op would come to me to confirm the shots were being stored properly; Coming from working with film, he was skeptical of digital storage I guess. Long story short, I told the Director of Photography \"Hey! I made these shuttle drives that the crew can take home\" and now it seems so obvious to me, but his response was basically to delete them, saying something along the lines that anybody could take those home and cut together their own version of the movie, and we'd have little way of stopping them. Lesson learned. During post production (which on pretty much every show I've worked on has happened during production to save time) anybody who isn't in a key position in the editing department will only have access to versions of the film that are basically useless, like proxies in low res with a big watermark on it, or they have to login to something like URL_0 which at least gives production an indication of who's looking at it. I don't know how it works in the big smoke, but in my experience there isn't exactly a colony working in the editing room. Folks in the office and on the production crew have no reason to ever go near the footage, and after the DMT, there's only about a handful of people you could ask if something were to surface online. The film industry has this weird feeling of being sort of like the military of the entertainment world. You work so hard for years and years just to be able to stay in it, and not have to work at Walmart on the side, that it'd honestly be suicide to betray a production. But I'm sure it happens. I have known people to get bad reputations and have to jump town or find other work. TL;DR: Movies at the theatre are encrypted on DCPs, a story about how I learned a valuable piece of set etiquette as a beginner, and the editing room doesn't have as many people in it as you would think (at least, in my experience)."
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86s3lz | How can PUBG (which requires a decent gaming pc to be played on computer) be played on phone? | Technology | explainlikeimfive | {
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"Pubg actually dont require some big major pc. It just has really shitty optimization. I actually know someone who plays it on a amd fx6300 and a gtx 960 and gets around 40 to 70fps depending on the enviroment (these drops happen no matter your system). Also when they port games over for mobile, they are made to run on mobile hardware. Youre not running it at 4k and 60fps on mobile, or even 1080. More like 720 tops at 30fps. With what would be considered low settings. There are also other things they do to detune it to be able to run on weaker setting, other then a big drop in detail and resolution. They know that with being played on a small screen, you are not gonna notice the difference in quality. Though, im sure its still gonna be horribly optimized and run like shit.",
"Watch some of the side by side [videos]( URL_0 ). The textures and little details of the world are all but gone. The details of the maps have been greatly simplified."
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86tiqs | Why do gaming servers maintanence times happen on tuesday morning in America? | Technology | explainlikeimfive | {
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"You'll always ruin someone's primetime. You just gonna choose who will be the unlucky winner. Also it makes sense for companies to do maintenance in the morning so if something goes wrong, they have the full workday to fix it, so then it depends on where is the actual company located.",
"Tuesday morning was calculated to be the least played time of the week for games like WoW and Everquest and so they started to do maintenance on those days. When WoW first started it was an all day event too, not just an hour or two. And yes, when you have a global game it will always be prime time play for someone. They chose the most efficient time where they would inconvenience the least number of their customers, which means scheduling for US. Additionally it is a good day to do things because you can prep on Monday, and have the rest of the week to handle any major issues that the maintenance may have found or made that can't be done in a single day."
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86tu22 | how this is possible: "Your PIN will be texted to you...for security the message will be automatically deleted two days later" | Received my new bank card and with it the instructions to get my PIN for it. > After a short while your PIN will be texted to you. For security reasons the text message with your PIN will be automatically deleted two days later. How is this possible? **edit:** the text itself - a perfectly standard, normal text: > "Your PIN number is *xxxx*. Please memorise or change it before deleting it. This text will be automatically deleted in 2 days time. | Technology | explainlikeimfive | {
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"There is a set of functions in your phone called the SIM application toolkit. It allows for a text message to trigger various things as well as being automatically deleted. Below is a link to the wiki article on the toolkit. URL_0 You can access the toolkit via an API I Android or iOS",
"This smells quite insecure, doesn't it? I found mention of an \"SMS fuzzing\" or \"SIM toolkit attack\" back in 2011 that allowed attackers to craft a nefarious SMS message that could force a target phone to send an sms or disallow all incoming SMS messages to it.",
"Did you have the banks app on your phone? And does that app have access to text messages?"
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86va2u | How do noise-cancelling headphones work? | Technology | explainlikeimfive | {
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"text": [
"They emit frequencies of the opposite wavelength to negate noise other than those they are emitting."
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86xy7p | How does a satellite dish work, and why did they become obsolete so quickly? | Technology | explainlikeimfive | {
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"Well, first, satellite dishes are not obsolete. Not even close. They are absolutely *everywhere*. There are literally billions of satellite dishes in use worldwide. There are over a billion satellite tv subscribers in the word, and satellite tv is just a fraction of the uses for satellite dishes. As for how they work, the dish collects incoming signals and focuses and amplifies them to the receiver. To send a signal, it's more-or-less the same process in reverse.",
"They reflect the radio wave from the whole dish to a single receiver to amplify the signal, it it called a parabolic antenna. If you have a similar receptive shape you can focus light to a point. most telescopes work the same way with curved mirrors instead of a lens. Why would you say that they become obsolet quickly?",
"I think OP is referring to those huge, room shaped home satellite dishes that I have not seen since the early 90's and/or the advent of small dishTV style setups."
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86z901 | How does higher quality microphones filter out most of the background noises? | Technology | explainlikeimfive | {
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"There are a few things that you should probably look at. Some microphones have different recording patterns. You can choose an optimal recording pattern depending on the setting. Cardioid mode records what is directly in front of the receiver versus say an omni\\-directional mic that will pick up in a 360 degree pattern. You can also apply what is called a pop filter. Pop filters work by reducing air flow towards the mic which effectively removes the popping and white noises often heard."
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86zdn7 | This new "Ray tracing" graphics technology Nvidia is all about | Wondering what this is, everyone seems to think it's pretty revolutionary | Technology | explainlikeimfive | {
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"Ray tracing itself isn’t new. It has been used in pre-rendered 3D graphics like animated movies for decades. It’s basically a method to simulate realistic lightning and reflections in a 3D scene by actually simulating how light rays would illuminate and reflect off objects. Before, to achieve good results this method needed so much computation power that is wasn’t feasible for real time applications like games. So presenting “real time ray tracing” is a big deal."
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86zv63 | Why different regions have different plug types? | Technology | explainlikeimfive | {
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"text": [
"In short, it could be worse. Various groups were formed to agree on standard types. These groups were mostly regional, ie. North American companies agreeing to use one type. British (and British-influenced areas like India) agreeing on different type. Yes, patents were involved. And of course, companies don't like to pay for other peoples' patents, so that was one driving force for compatible standards. And of course, regional groups that decide standards often try to improve on other groups' standards. The UK type is believed to the be safest and much harder to accidentally pull out than the simpler, 2/3 prong US style. (Although in my mind, this comes off as national pride.) You can see the same thing with computer ports. Look back to the 80s and you can see joysticks and drives used all sorts of types. Thank God for USB."
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870x3v | How do power companies determine the cause(s) of outages? | Is there some kind of mechanism built into the electrical cables/transformers/etc. that helps them find the source of the failure? Do they have to rely on customer complaints? Or what? | Technology | explainlikeimfive | {
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"So each power company has a control room that shows all the substations linked. Each substation has protection relays, the relays look at different zones along a power line zones 1-3. One substation looks down the line to next substation and that sub looks back at the previous. As their zones 3 overlap we know that if both stations trip then the fault is some where in the middle of the line, if zone one on either trips then we know the fault is closer to one of the stations same with zone 2, the relays calculate the zones based on the length of the cable and distance from the substation. Note that relays used in the substations aren’t like everyday relays they are a bit more complex. That may not be ELI5 but that’s the best I got."
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871dbl | how does Bluetooth works? | I tried to search web for a while, but i want simple explanation from you guys. | Technology | explainlikeimfive | {
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"text": [
"It is a wireless technology not as powerful as Wifi. Two sets of chips, one on each device talk to each other through radio frequencies. Fairly simple but more techy read: URL_0"
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871srr | Why does GTA5 use P2P servers for their Online suite when it's the reason hackers are so abundant? What are the benefits of not using dedicated servers? | Technology | explainlikeimfive | {
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"The advantages are : - Very low cost compared to Dedicated servers - People in areas that wouldn't get good ping due to location would get matched with other people from that area, so some people would get better ping A good explanation of the three most common network models can be found at 10:45 of this [video]( URL_0 ) by Battle(non)sense :)",
"I'm far from an expert on this so I might be 100% wrong. I think it's the cost, having dedicated servers means you basically have a dedicated area full of processors managing all the player activity, where as with p2p the processing load is handled by the players. Source: some guy bitching about youtube and talking about why bitchute could be a good replacement. Can't remember who or the exact explanation but I think it was something like that."
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871y7m | how does a food processor and a blender give you such different consistencies when all they both do is have a blade spinning in circles. | Technology | explainlikeimfive | {
"a_id": [
"dw9jwhz"
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"text": [
"I would think that it is the shape of the blades. One may have just a two pronged flat blade. The other is more articulated and has additional arms/blades. Here is a cool video (kind of) touching on the subject. URL_0"
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872qs4 | What is 1x when it comes to cell networks? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"It's an older 3g network standard that was used by some networks, like Verizon and Sprint. It's slower than the 4g network (LTE) and the later 3g network (EV-DO) so you'll probably struggle to do much Internet browsing on it, but phone calls should work fine.",
"It's mostly similar to edge or 2G only on CDMA networks. Phone calls should work but MMS and SMS may not work"
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874yob | How is my brand new Amazon firestick already connected to my Amazon account | Technology | explainlikeimfive | {
"a_id": [
"dwa8dkc"
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"text": [
"Serial number/bar code on the box? They scan it before it leaves the warehouse a part of your order and associate it with your account in their database. When you turn it on it checks in with Amazon and it says something like “hey its me, here’s my serial number you got an account record for me?”"
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87648k | how exactly do anti missle defense systems work?? | Technology | explainlikeimfive | {
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"Depends on the type of system. Most use radar to identify incoming missiles and the launch a missile to intercept it. Modern interceptor missiles are generally kinetic kill vehicles. Which means they carry no explosives and rely on precision targeting and pure kinetic energy to kill the incoming missile. Older systems like Phalanx, Kashtan, and AK-630 used super-high rate of fire gun systems to shoot down incoming missiles. Once a radar lock was achieved on the target the system would fire hundreds or thousands of 20-30mm projectiles at the incoming missile in an attempt to swat it out of the air. New experimental systems use lasers to destroy missiles and shells. Modern ship, aircraft, and tank anti-missile systems also utilize a wide variety of electronic countermeasures like radar jammers, flares, chaff, dazzling lasers, etc.",
"Are you a Russian bot trying to happen upon some US military secrets?",
"1: see missile. 2: shoot down missile with other missile. 3: ??? 4: profit.",
"Don't forget the Russian system where they literally explode nuclear bombs at high altitude to kill incoming nuclear bombs.",
"Lots of super fast defence missiles blow up slightly slower incoming missile before it gets close to its target."
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8784oi | Why Fortnite can have a cross platform party system but other games can’t | Technology | explainlikeimfive | {
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"text": [
"It adds some extra developmental road bumps. A lot of times the same game on different platforms will have minor differences throughout the code, mostly unnoticable to the player. For cross-platform multiplayer, the game has to be functionally identical across all versions. Not a deal-breaker itself, but it can add some time to development. Issuing patches has the same complications. Another aspect to it is getting the platforms to agree to it. In the past, Sony and XBOX haven't always been willing to allow developers to have cross-platform multiplayer in their games. It seems maybe attitudes on this front are changing somewhat. TL;DR: The majority of multiplayer games *could* have cross-platform multiplayer, but it involves a lot of extra work for the developer and in a lot of cases is deemed not worth the trouble.",
"Fortnite only has cross platform for playing with friends. You don't play cross platform otherwise. The main thing is balance. PC users have a huge advantage since a keyboard and mouse is a much more capable input method than a controller, and light years superior to a phone touchscreen. This means people using controllers or touchscreens get slaughtered in competitive games like Fortnite, causing users of those platforms to hate the game.",
"There are two major factors. TLDR: Fortnite was likely able to sway MS/Sony due to it's size to get a little special feature but overall the major thing blocking it is MS/Sony itself. A: Ecosystems B: Development A is by far one of the biggest actual roadblocks which is getting Sony/MS/etc to get on board with allowing XboxLive/PSN/etc players to join in on the general PC server. There have been 'bugs' and such in other games where players leaked through (Even fornite awhile back for a weekend) but short lived as it would get shut down. MS/Sony typically don't have much of a finical reason to allow it and often have more to NOT ALLOW it as to keep players into THEIR ecosystems. Fortnite massive base likely helped sway them to make an exception of some kind but even then it isn't that big. Many other devs will try to file for the exception and likely get turned down. At most if you pledge exclusive to one console you might be able to get cross play with PC. Development wise it is an extra hurdle BUT with good coding standards and planning from early stages it should be possible. But given how unlikely it the approval is many might not even bother with this hurdle seriously because \"why bother\". If MS/SONY/etc suddenly changed their stance tomorrow many older games would need some patches to make it possible because they where never programmed with this in mind."
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879lqi | How have trains managed to stay relevant through the progression of technology? | Technology | explainlikeimfive | {
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"Because they work well. Thats the core of it, aociety works heaving on a “if it isn’t broken don’t fix it” mentality. That being said it is still basically the best option for large-scale freight over land, durable, quick, and cheap.",
"They're INSANELY efficient. The amount of cargo one locomotive can pull would cost hundreds of times more if carried by truck, and it's even worse if you go by plane. The trade off is that your delivery and pickup points are limited, and the US rail system is chronically overworked, so it's slower in a lot of cases to trucks.",
"Very low cost per ton per mile. Once you'd got the rails in place, it's almost impossible to beat rail transport. You can do barge traffic on canals for the same sort of price, but you have to have even more difficult logistic problems; you either have to dig a canal or go out on the open ocean where there is weather.",
"Trains are the most efficient way anyone has yet come up with the move large quantities of stuff over land. Trucking is more flexible, but also much more expensive on a per-ton basis.",
"Trains improve with the progression of technology. Trains from 100 years ago aren't as good as trains from now, and likely 100 years in the future our modern trains will be not as good as them. Otherwise, as others have said, trains do one thing really really well, which is haul cargo using as little fuel as possible per ton of cargo moved, and we just haven't come up with a method of hauling cargo over land that's nearly as efficient/cost effective/\"green\"(depending on how you measure \"better\") as a modern diesel cargo train."
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879nwe | what’s the difference between all the different types of lightbulbs? Incandescent, fluorescent, LED, any others? | Technology | explainlikeimfive | {
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"text": [
"Brief explanation: **incandescent**: *very* thin tungsten wire is heated by putting electrical current through it, this creates a lot of heat and some orange looking (\"warm\") light. Not very efficient as a light source, quite efficient as a space heater. The wire burns out after a while. **halogen lamp**: think incandescent bulb version 1.1: still has a thin tungsten wire, but the bulb is filled with special gasses that allow the wire to get hotter without burning out. This means a little bit more light for the same amount of energy, but still not very efficient. **flourescent light**: glass tube with electrodes at either end, the glass tube is coated with chemicals and filled with special gasses. Voltage is applied to the electrodes and through some tricks the gasses are heated to such a point where an electrical current flows through the gasses in the tube. The electrons then bumb into gas molecules which creates UV light, the UV light hits the coating of the tube that creates visible light. More efficient than the above, but still wastes energy as heat. Also contains at list a tiny amount of mercury for the \"startup trick\". **LED**: a tiny piece of special material called a semiconductor is created that creates light from electrons bumping into atoms (gross simplification). By choosing the right semiconductor material you can choose the color of light, for white light the most efficient way is to again create UV light which then is converted into visible light by some material (similar to an fluorescent tube, material is called *phosphorus*). Quite efficient, but still creates quite a lot of heat and unfortunately cannot deal well with getting hot - > we need some kind of cooling e.g. a metal heat sink.",
"Characteristics: * **Incandescent:** Very cheap, but extremely power hungry. Runs very hot, meaning it has the potential to start a fire or melt a fixture if used carelessly. Bulb is made of glass, which can shatter into very sharp pieces. Dimmable. * **halogen:** Like incandescent, but even hotter, so even more of a fire hazard. Must be handled extremely carefully as the glass is damaged by fingerprints. They can shatter violently. A bit more power efficient than incandescent. Dimmable, but this can dramatically shorten their life, as the construction specifically relies on the high temperatures. * **fluorescent:** Costs more, but uses little power. Can take a long time to warm up to full brightness. Still made of glass, but doesn't get nearly as hot. Really hates being turned on and off, making them a very bad fit for bathrooms, closets or any other place where the light is turned on for just a bit and quickly turned off. Best used in businesses and offices where they're turned on once at the start of the day, then off at closing time. Not dimmable by default, you need special ones. Contains a small amount of mercury, which isn't a huge deal but not completely ideal. * **LED:** Very power efficient. Turns on instantly. Can be toggled on and off all you want. Comes in a huge array of shapes and colors, from normal looking bulbs to light strips. Exists in color changing varieties with a remote control. LEDs themselves are very dimmable, but LED bulbs running from AC power are far trickier, but still possible. Often made of plastic, so they can fall without spreading broken glass everywhere and usually survive it without any harm. Both fluorescents and LEDs at the start produced a very unpleasant sort of light, but these days this is pretty much gone. You can get them in any color from pure white to incandescent-like yellows. TL;DR: Just get LEDs."
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879oc3 | Why is it that despite how much CGI has improved in the last 20 years it is always possible to tell when human faces are digitally rendered? | Technology | explainlikeimfive | {
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"text": [
"The term is “uncanny valley.” And yes it is much harder to make something real look realistic. Our brain is much better at finding something strange about things that we are used to.",
"Humans have spent many many many generations perfecting our ability to identify people, and faces in particular. We're so good at it our brain can pick faces out of a lot of different inanimate objects. But along with that, we're also keyed to spot differences. Whether that's inter-tribe (they don't look like us), or more basic safety (they look sick/feverish/diseased), we're very good at it. CGI hasn't gotten to that point yet, especially when we see them move. It's the reason for the uncanny valley; stuff goes from 'this is obviously a representation of a face' to 'this is a real face but something is HORRIBLY WRONG.' I suspect there's a part of the design that's intentionally making them look slightly more off than we -can- make them, to avoid falling into that valley.",
"Humans have a large part of their brain devoted to processing and interpreting facial expressions. Fooling that kind of hardware is very hard. Hard edged, man-made objects are computationally much easier. They add some shine to CGI facetones because even though you spot it as fake, it's less fake than flat facetones would be."
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87dwlp | How does a computer - which operates on fixed inputs/outputs create entropy to generate things like private keys? | Particularly with smaller USB connected devices like 2FA, or cryptocurrency hardware wallets that don't have access to 'random' things that could be used to generate a key like fan speed, power draw, temperatures, etc etc | Technology | explainlikeimfive | {
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"High-quality random number generators use a small amount of nuclear material. If there's one truly random thing in this universe, it's nuclear fission. You only need a small dollop and two sensors to make an effective, but slow, random number generator. If your device doesn't need to produce more randomness over time, you can preload it with some random bits. A cryptocurrency wallet doesn't need any randomness to store your wallet information. It only needs randomness to create a new asymmetric key pair."
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87gmgd | How can the information I provide on the internet be used against me in a malicious manner (and some off topic ranting about surveillance)? | Technology | explainlikeimfive | {
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"Humans tend to fall under the same habits. Birthdays, pet names, favourite game/movie/book & the repetition of one password across multiple platforms. Example. I have a friend. He's a total fucking Halo fanboy. I can guess from this fact that his password might incorporate something Halo related. Master Chief, the main protag of the game is code named Spartan117. The other day he gave me his wifi password. It's Spartan117@. People tend to use one password for multiple sites. If I was bothered enough I could jump around and likely gain access to a variety of his accounts. Some of these may or may not include $$$.",
"> Personally, I don't have anything to hide. If someone wants to track my every movement to find out just how much I enjoy making clay sculptures, more power to them, and to be honest, I think people are really flattering themselves when they genuinely believe they are being systematically tracked. If someone finds out how much you enjoy making clay sculptures, that's great. But what if they also find out about the medical condition that you've been Googling, and because of that you get turned down for a job, or for an insurance policy? What if they find out about that embarrassing fetish you have, and threaten to tell your clients/your friends from church/your conservative parents unless you pay them some money? What if they are able to figure out the times you're out of your house, and where your house is, so they can break into your house in the knowledge that you'll be at work at certain times of day? > I think people are really flattering themselves when they genuinely believe they are being systematically tracked I don't think I'm being systematically tracked. But I *do* believe that when I apply for a job, my potential new employer will do a basic Internet search to see what they can find out about me. I know what will come up in that search (and it's nothing that I'd be worried about a potential employer finding out), but I also know there are things I've used the Internet for in the past that I *wouldn't* want a potential employer to find about - not because they're illegal, or even particularly embarrassing, but just because they're not things I would share with an employer."
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87gmnd | Why|how do we make reddit bots that remove post automatically? | Technology | explainlikeimfive | {
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"As to why, we make them because they are effective at combating spam and ensuring a level of quality without requiring a human to operate. A bot only requires a human to take a look at appeals and complaints, ie. to correct any false positives or negatives, instead of a human having to manually go through all posts. For how, a bot is given certain triggers (for example, common words or features in spam messages) that it looks for. Based on these triggers, the bot decides if a post is spam or otherwise against the rules, and if it is, removes it. Of course, a bot requires a human backup, as it may have false positives and false negatives, but a bot vastly reduces the work load on admins in a subreddit."
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87juzo | Why did electronic toys in the 90's and early 2000's specifically warn not to use rechargable batteries? | Was there a genuine safety/performance issue? Or was it just a marketing ploy to sell more batteries? | Technology | explainlikeimfive | {
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"Ni-Cd rechargeables output less voltage (1.2V vs. 1.5V) so certain devices that require a certain voltage would not run properly on those batteries.",
"Two reasons. The first has already been covered: Voltage. The second is more subtle. Zinc Chloride, Zinc-Carbon and Alkaline cells all have a substantial internal resistance and quite a poor current capability. This protects against shorts and can be used by simply designed toys to limit current. NiCd and NiMH have virtually no internal resistance, so if the toy was relying on the battery to limit its current, it would draw dramatically more current than it was expecting, often involving physics, such as heat, light, fire and motion.",
"Rechargeable batteries typically have lower nominal voltage, so they may not run the devices properly. The lower voltage also may cause the device to draw more current, which increases heat",
"A lot of responses have talked about lower voltage, but let me just expand a little about internal resistance. Alkaline and older 'heavy duty' dry cells have this, and rechargeables generally don't This is a tough property to explain, but basically the battery itself acts as a limiter to how much current (amps) it can send out. If you start trying to draw too much power from the battery, the battery's own resistance will start to warm the battery up, further sapping power. This would eventually hit an equilibrium not allowing any more power to flow. A sort of internal limiter. As /u/Hattix has already said, this can be used on basic devices to stop them pulling more than a safe amount of power. Rechargeables don't have such limits, so can over-power a cheap device that's expecting that internal limitation to kick in. [This]( URL_1 ) type of basic LED torch can have this problem. I had one and managed to kill it with rechargeables. LEDs need a limit to their power - if you connect them to an sufficient power source they'll just keeping pulling more and more current until they cook themselves, you have to limit it. In a decent torch that would be done by adding a [resistor]( URL_0 ) in line with the LED. The resistor resists the flow of current, and keeps the LED in check; stops it pulling too much power and killing itself prematurely. But resistors cost money. In the cheapest torches then, you just forget the resistor and depend on the internal resistance of the non-rechargeable batteries you've put in it to hold back the power and give the LEDs long life. Sure it's not ideal, but it'll work in a pinch. Put rechargeable batteries, which have no internal resistance in such a torch, which has no built in resistors, and the LED's will just keep sucking power until they go pop, which they will in pretty short order."
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87l1jl | How did toys in the 70s/80s produce the smoke | Remember those robots where smoke came out of its mouth or the toy trains where smoke came out of the funnel. How did they do this, was it toxic (most likely) and how long could that last for before it ran out. Thanks | Technology | explainlikeimfive | {
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"I had a toy train and a toy godzilla that blew smoke. You put drops of oil in that pretty much just burned into smoke. Refill as needed.",
"Most trains dropped glycerin, or a glycerin+water solution, onto a hot element. It wasn't exactly \"smoke\", but it looked like it. It was steam and tiny glycerin droplets. It is surprisingly clean, leaving neither soot or an oily residue. Mom's back then were sticklers for clean clothes, more than concerned about toxins, back in the day."
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87lgaq | Why can't you make emergency calls with communication apps like Skype? Having WLAN access in areas with no cellphone reception or landline isn't exactly an unlikely scenario. | Technology | explainlikeimfive | {
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"When you're on something connected to the Plain Old Telephone System (POTS), every entry point has a distinct 911 call center it is supposed to go to. Landline in your house? They know where to route it. Cell phone on a tower in a back road? They know which tower you're pinging off of, and so which call center to route you to. If you're calling from your laptop while you're on business in New York, when your regular office is in San Francisco, but your VPN endpoint is your corporate headquarters in Austin Texas, how the hell are they supposed to know where to route the call?",
"You can make emergency calls, provided you know the phone number of the nearest police station. Usually, you don't - you dial 911 or some other shortcut code. Alas, that shortcut code works geographically. If a cell tower in Topeka gets a request for a 911 call, it is routed to the Topeka call center. The Internet is not geographic, which makes Netflix mad, so there is no way to know the location of the call. If you Skype to 911, are you going to be happy if you get the Redmond WA emergency center because that's where Skype's world headquarters is? Unlikely.",
"This is Skype covering their ass. Traditional telephony companies are required to maintain highly reliable access to emergency numbers. They face investigation, fines, even losing their licence if they don't maintain service levels - we're taking 99.999% levels. This has driven highly redundant networks - which come at increased cost. Alternative voice apps don't have the legal requirement so they save money by skipping redundancy. And that's why they include the instruction not to make emergency calls. In the UK you used to see similar warnings on cordless phones, which require mains power to operate - wired phones can function in a power cut."
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87lrj7 | How do scope/optic reticles work? | I was wondering how reticles on guns optics work. Are they drawn on the lens or the inside lens? Are they made inside the optic? And how are they not blurry when seeing through the optic? I mean, it would be ovbiously blurry if you drew the lines on a optic, right? | Technology | explainlikeimfive | {
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"Scopes actually have multiple lenses internally that you can't see. There are (at least) two spots where the lenses bring an image into focus, called the first and second focal planes. These are points where the light from the image in front of the scope converges. Any object placed at these points will appear to be in focus, projected on top of the image in front of the scope. A reticule can be located at either focal plane. If it's located at the first focal plane, the reticule will change size as you zoom in. If the reticule is located at the second focal plane, it will stay the same size regardless of zoom factor."
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87m3x9 | How Do Rolling Codes Work | Garage Door Openers, Key Fobs, etc. I know, (or think I read), that they send a unique code each time, and upon successful authentication, the garage door, for example, will give the next code to the remote at that point, so it won’t be the same as the next time, but what stops someone from “listening” to the garage door when it sends back the next sequence to just know what the next code will do? How does it communicate openly over radio back & forth and yet somehow still stop anyone from “listening” in and getting the information to force open it the next time? | Technology | explainlikeimfive | {
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"> the garage door, for example, will give the next code to the remote at that point Not quite. you're correct in that the key will send out a code and any car that recognizes that code will unlock or lock itself. However they don't communicate much beyond that. The real story is that both devices have, for a very simplified explanation, an very very large list of codes. Both devices have this list. When the key transmits a message it will take the top code on that list, transmit it, and move on the the next item in the list. The car will hear the message, compare it to the next hundred or so items in his list, and if there is a match it unlocks the door and moves the list down to the keycode it heard to stay in sync with the key. Anyone listening in will just hear that one code going trough the air, and once that code is gone, it's gone. You cannot reuse it. You however can't know the next code on the list, or the next one after that, or after that, and there are too many codes to guess possible, so you're not any closer to opening the lock than you were before. Imagine they are just counting. Key says \"4\", and car says \"HEY! My list is on 4 too! That must be my key!\" Then the next time the key says \"5\", and the car says \"Yes, I have code 5, locked!\". But if you come along and say \"54\" the car responds \"Nope, not on the list\". If you use the code \"4\" the car promptly goes \"No, I already used that code\". Then the key comes along and says \"7\", and the car once again goes \"oh, I know that code, it is a bit down my list. The key must have accidentally called out when I couldn't hear. No biggie, 7 it is! Open!\""
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87n81v | How do subscription based services know when you've changed your credit/debit card and then change your payment to that new credit/debit card? | My credit/debit card(s) have been compromised in the past, and when the new cards were given even without giving any information to any of the services they automatically changed to the new information of the card. | Technology | explainlikeimfive | {
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"I got an explanation from AAA telling me that my bank notified any company that is under auto pay from my debit or credit card when I get a new card. AAA let me know that my bank updated it for me. I freaked out when my car insurance updated itself but calmed down a little when AAA notified me that my bank did it for me.",
"This is a standard feature available to merchants that is run by the card networks. Visa’s, for example, is called [Visa Account Updater]( URL_0 ) (PDF). Issuing banks let the service know when your number has changed and the service lets the merchant know so they can charge the new number."
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87om1v | Why do military cameras have such terrible quality? | Technology | explainlikeimfive | {
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"Footage is heavily edited, of course, but a lot of what you're seeing is from an aircraft that's probably at 25,000' altitude a few miles away. It isn't like the Predator or Global Hawk is getting right up on the action.",
"Depends on the video. Sometimes what's publically released is intentionally diminished, sometimes the recording device is old. For example the last F-22 was made in 2010, but production began in 2001. What as digital camera quality in 2001? Not that great compared to today. Sometimes it's a video that's been uploaded, downloaded and re-uploaded to video sharing sites like liveleak and youtube many times. Each time the quality is degraded. Sometimes you're looking at a thermal image, which doesn't have the same resolution as a color image. Keep in mind the military has some really high res cameras for intelligence gathering, so it's not like they don't exist at all.",
"Black and white video are likely from a night vision camera. So it might be film in lighing condition where you would thing it is completly dark if you looked with your own eyes Look at [this video]( URL_1 ) that compare a night vision camera with a GoPro. The areas beside the road is completely dark in on the gopor but you can see things with the night vision. The area beside the road is quite well lit as thee are lot of light from the road illumination it compared to the amount of light compared to being far from any electrical light with only illumination from stars. Another alternative it that is is a thermal camera. with that can you see in total darkness by detecting heat radiation from objects. A example is [here]( URL_0 ). So the video with be black from a gopro where a night vision show you what happen. For day time photo cameras like a gopro cam be used for film ground operation. But you still use the same cameras in the air as you do during the night as thermal cameras can show thing that are invisible in regular cameras A thing to consider is that if the video is from something airborne it is likely from a camera with high magnification and that will reduce the image quality compare to a camera with wider lenses. Sensors can also be some years old. Thermal and night vision systems are not cheap especially if you need them to last and survive in environment like a aircraft. Their resolution might not be the best but might be good enough for its usage. A targeting pod for a aircraft cost more then a million dollar."
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87omw6 | Why are VLANS required in order for switches to communicate with other switches/routers? | I assumed VLANS were made to segregate, so why would not having one make communication between switch and router/switch impossible? | Technology | explainlikeimfive | {
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"VLANs aren't required for switching at all. VLANs are a configuration overlay across a set of hardware that associates ports and network traffic with a virtual LAN. That said, you can configure things so that VLAN tagging is required. To take a step back, in general only ports that are tagged correctly can see traffic with that specific tag. Those tags can span switches and routers, so theoretically if you have a consistent VLAN configuration traffic tagged with that specific tag can only go to router/switches/ports with that tag. Now if you have a router or switch that's not VLAN-aware plugged into a network with VLANs it -might- see that tagged traffic depending on how that VLAN-aware device is configured. It might even route those packets correctly. The internet isn't VLAN-aware, so generally the VLAN tags are stripped out at the edge on the way out then put back on the way in."
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87rocc | How a mobile app detects and processes inputs from a touchscreen? | In other words, I wanted to know how a touchscreen shows, say "double-tapping" or "pinching", and how an app designer can then use those inputs to allow a user to complete certain actions. I can't really explain this better, but I was wondering about how Instagram now allows you to pinch the screen to zoom out in stories. | Technology | explainlikeimfive | {
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"App designers don't really do that - the OS designers program input and create API's that programmers exploit to perform operations. Instagram allows you to pinch to zoom because the OS maker programmed that as part of the OS as an API that Instagram calls.",
"Ooh ooh! I know this one! I did a report on capacitive panels during a multi-touch class in grad school. Time for the ELI5. (More like an ELI9, but we'll see) So your phone screen. It has a bunch of tiny, invisible wires across it like a grid, running left and right AND up and down. Those teeny wires are the sensors. Here's how one wire works: it has a tiny pulse of electricity, not enough to feel. The phone measures how much time it takes for the pulse to fade away. If nothing is touching it, it's really quick. If something big and watery is touching it, like you, your body holds on to the pulse longer, so the phone knows the wire is being touched. Why does touching it make the pulse go away slower? Instead of electricity, let's imagine heat. We have a heater. It takes a known about if time to cool down when it's turned off. Now sit a metal bucket of water on top of the heater. It will heat up too, but now when the heater is turned off, it will take longer for both the heater and the bucket of water to cool down. The wire is the heater and you're the bucket. But it happens in the phone faster than you can see. What's really great about this is your don't have to actually touch the wire, and electricity never actually goes through you- you just need to be close enough to it to make the pulse take a little longer. So the wires can be on the bottom of the glass of the screen and it works fine! So one wire can tell if it's being touched it not. We have a big grid of the wires, and the phone takes turns checking each one. It's like the rows and columns of Battleship- each wire is either a number or a letter, and where they intersect is where the finger must be. It takes turns on each wire really really fast, and it can identify more than one touch if multiple wires are triggered, and it can even tell the size of the touch by how many wires next to each other are triggered at the same time."
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87rwek | On a low level, what is Ctrl + Z doing? | Technology | explainlikeimfive | {
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"When you make a change to a document in Word, for example, Word saves a copy of that change in memory and puts it on a stack. Stacks are a type of data structure where the data items are organized in Last In First Out (LIFO) structure. Sort of like a stack of pancakes, the newest one goes on top and is also the first one to be eaten. When you undo, the last change you made is read and removed from the top of the stack, and then used to revert your changes. You can read more about stacks here: URL_0 Source: computer science student",
"Real eli5 at the end of the post. Every answer so far forgot to mention a pretty important fact: Every program is responsible for handling the key combination itself. Sure some very basic stuff like text boxes have their copy, paste, cut, undo, redo,... functionality provided by windows, but that's it. Programs that are more complex (paint, Photoshop, even Microsoft Word is a lot more complex than just a simple text box) have to implement the undo thing themselves. There are a few different ways to do it, and most programs can get away using a sort of \"cheat\". They simply store a full snapshot of the state of what you are editing (text, images, video, audio, scripts,... Whatever) up to a certain limit. Many programs have a setting in their options window for that (called something like undo buffer size). Some programs don't save full snapshots but instead they save the changes (deltas) which takes a LOT less space. And yet others (where applicable) even save what it is you actually did. For example in paint it would save \"start stroke at 234,921 and go to coordinate 764,613, then release the brush\". And on undo it would just \"regenerate\" all the previous actions again onto a blank canvas, omitting the last action. All approaches have their advantages and disadvantages and it depends on the specific program what strategy a program actually uses to implement its undo and redo functionality (if it even has one) Eli5: Program saves whatever you are doing everytime you do something into a big list. When you undo it just goes back one step in the lost and loads the data there.",
"Everybody answers about \"Undo\" in Word but the first thing I thought was the suspend feature of bash (in Linux). OP, you should provide context.",
"When you hold down the control modifier key and hit Z, your keyboard hardware sends 26 to the keyboard interface circuit. Your operating system has a driver for that keyboard interface circuit, that decides which keyboard user has \"focus\" and sends keystrokes to them. If Ctrl-Z does something special in a program, it's because that program's keyboard handler has \"if (data = 26)\" in it someplace. When Ctrl-Z does something different at the system level, there is an \"if (data = 26)\" someplace in the driver, before the keystroks is passed to a program.",
"On the lowest level it sends a control signal followed by \"z\" signal. Most operating systems implement standard functionality that captures it and reverts last changes made to the current system state. Some applications capture it themselves and undo the last Operations from a list of changes that the application kept track of, since they save all recent changes in computer memory - before saving it to your harddrive. That is why you have limited number of revert/forward (ctrl+y) actions that you can do, depending on the application you are using :)",
"Ctrl+Z is commonly implemented through a \"command pattern\". When you bold text, move a box, or whatever in your program, a \"command\" is created. The command is an object that contains the data of the change (e.g. box id, 'new location') and two actions: - do - undo If you tell the command to \"do\" it's action then it performs the action. The \"undo\" action performs the logically opposite function. Each action's do & undo code is specific to the command. For example, a \"move box\" command has the logic to move the box. The \"bold\" command has logic to bold text. From a command perspective we don't really care how it is done, just that you can \"do\" and \"undo\" an action. These commands are held in a \"command buffer\". When you press Ctrl+Z the undo action of the last command is called. The prior command becomes the last command and it can be undone. This can be repeated until there are no more commands to undo. You can also \"redo\" a command (Ctrl+Y) which calls \"do\" on the last undone command. Like the undo chain, there is a redo chain to the next command that was undone. [The command buffer is a \"doubly linked list\"]."
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87s1qf | Why is it that most things that use AA batteries have only 2 spots for batteries, as do most things with AAA batteries have 3 spots for batteries? Is that number a coincidence? Or do they do this on purpose? | Technology | explainlikeimfive | {
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"It's done on purpose! 2 AA batteries produce 3V when in series with each other. This voltage is commonly used in low power electronics. Whereas 3 AAA batteries would produce 4.5V in series, this would be more commonly be used to power a motor or light source of some kind. But mainly the difference in number of batteries is moreso to do with the voltage requirements of the device to be powered. AA and AAA batteries both produce 1.5V on their own the difference being the power they hold. AA holds 2400mAh and AAA holds 1000mAh. So bigger number means battery lasts longer.",
"Regarding the number of batteries - AA and AAA batteries each have a voltage of 1.5V. However, a AA battery can store more energy per battery than a AAA, so it is preferable to use AA if space isn't a limiting factor. Most electronics require a minimum of 3 volts to operate, hence 2 batteries are used (1.5 + 1.5 = 3V). Depending on what electrical hardware the product has, the requirement may need a higher voltage, like 4.5 or 6 volts. 3 volts are good for sensors or simple DC motors, while ~6 volts are good for processors (like your phone). A good example is a TI 83 calculator. 4 AAA batteries are used because it needs 6V to operate, and AAA batteries are used because they're smaller so you don't have a huge calculator. If you have enough space, you can have plenty of large batteries powering the electronics. IIRC I have an electric piano that uses 8 D batteries. That makes 12 volts for the speakers to operate. The designers could have chosen AA, or AAA batteries and satisfied the voltage requirements. But they chose D batteries because they hold a lot more energy, and there is plenty of space in this piano for them to fit. As a result the piano can be played for a lot longer time period. So to answer your question - the number of batteries is dependent on the type of electronics. The size of the battery is determined on space. In general if you need a higher voltage for a small electronic, space is a limiting factor, so smaller batteries are used like AAA."
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87s46l | How does CGI “age?” If something looked real “at the time” why does it look less real now? | Technology | explainlikeimfive | {
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"A slightly different approach to the other answers which sum up to \"We compare against modern CGI\" The increase in quality for CGI has to do with the level of detail you pay attention to. At first, CGI was clearly using hard angles where it should be using soft curves. So, when someone finally got soft curves right, it was \"So realistic!\" But now the thing which made CGI obvious was the colors and shadows. Someone got colors and shadows right, and CGI was \"So realistic!\" But now the thing which made CGI obvious was the use of bulk motion where individual motion should occur (like clumps of hair instead of strands). Then we had issues of being TOO perfect. Issues of no superfluous motion (random breeze, background people, facial ticks). Not sure what precisely the latest issues are, and likely have some of the listed issues out of order. But it boils down to the people who work on CGI technology addressing the issues they are aware of as the most glaring, and then consumers of the media noticing new problems and focusing on those as the method of determining what is real and what is not. So, when you look at older CGI, you bring with you a host of expectations, but that CGI wasn't even aware of needing to satisfy half of your needs.",
"The baseline of comparison isn't reality, it's other CGI. When CGI first came out, it was obviously CGI, but it still wow'd people because you had this fantastic amazing stuff happening on screen. As the push to make CGI \"realistic\" increased, new CGI was always compared to existing CGI. Stuff \"looked real\" at the time because that was the best there was at the time *compared to other, less real, CGI*. Now it looks fake because we have better CGI today and that's what we compare it against.",
"One of the factors for me was HD. I remember thinking Star Wars had the best special effects when watching it on VHS, and then blu-ray came out and, oh boy, those miniature models actually look like miniature models now. The same thing is happening with 4K where it’s making CGI look more fake.",
"same way kids were super excited when action figures could bend their arms. or when High Definition was 720 pixels.. it's a comparison to what was available. nobody thought those effects \"looked real\" but they looked better than anything they had seen at that time so they were excited and praised the special effects.. i.e. a movie review of \"E.T.\" when it first came out could have \"best special effects I've ever seen!\" but that doesn't imply they ever thought it was realistic at all.",
"well a lot of it is to do with expectation - we just expect better now. Like my son is 2 and we've not let him have any sweets or cakes yet, so he thinks bananas are the ultimate in taste sensation. The other thing is when something is a thing you've never seen before you're so taken with the newness that you don't notice it doesn't look quite right. Your imagination fills in the gaps. That's why kids loved the old Dr Who's - they'd _never seen anything like it_ I would argue a little with your premise though - on the whole, bad effects have _always_ been bad effects. The rubber Arnie head in the Terminator _always_ looked like a rubber Arnie head, and the Scorpion King always looked like, er I dunno what it was meant to be. But the good effects knew their limits and pushed them (there's another level too - The stop-motion skeletons in Jason and the Argonauts _always_ looked liked stop-motion skeletons but nobody cared because OMFG HE IS FIGHTING SKELETONS)",
"So, the reason that CGI ages is more impressive graphics makes your brain less prepared to fill in the details with older CGI, but even current CGI isn't \"perfect\" and you still have to subconciously \"fill in the gaps\" Often this is why you also \"remember\" old favourites as perfect until you revisit them. The brain fills in the gaps when you're consuming CGI If you go back and play a playstation game and it looks pretty blocky and terrible, but at the time it looked \"amazing\" right? If you play enough, you stop noticing the *very obvious* dated graphics and it begins to look good again (Had this when I replayed an old Final Fantasy) The closer to perfect CGI is, the less you need to subconciously \"ignore\", and the better the CGI you are used to, the less prepared you are to \"ignore\" flaws in older CGI.",
"The baseline wasn't so much reality as it was the previous generation of CGI. Compared to previous or just worse attempts, it looks incredible. Same as why today's look way even better if you.compare them to the ones that don't look as good when we look back.",
"I see a lot of good answers, but I think the /best/ answer is just the fidelity of televisions and various mediums to display media. Ever watch Matrix on VHS? That shit still looks real. Even on DVD, you can't really tell how bad effects are. In a way, we've painted ourselves into a corner where we enjoy media less because the fidelity is so much better on televisions and devices that present media to those televisions (blu-ray etc). If we had 4k TVs and blu-ray when the Matrix came out, we would have thought the effects looked pretty bad. On 480i or p, things still look pretty good.",
"Like others mentioned, your basis for comparison for CGI is previous CGI—not reality. Interestingly enough, this is why movies like Independence Day and Jurrasic Park have aged so well. The emphasis was on practical effects with CGI added as icing on the cake. Movies that rely primarily on CGI will always look dated at some point, because there will always be something better. I think the uncanny valley is part of this conversation, too, but that's a separate issue.",
"Well... some people praised them. Not everyone. Some movies, like Jurassic Park, were pretty universally praised in the CGI department. The ones that haven't held up tended to have mixed reactions at the time. When Final Fantasy: The Spirits Within first came out, it was *marketed* as being ultra realistic, and a lot of people recognized that it *was* technically impressive compared to other existing CGI... but I also remember it being **super** uncanny valley when it came out, and a lot of people shared that sentiment. When Toy Story first came out, people were impressed with how realistic the toys looked, but nobody was praising how the humans looked. I remember people saying it would have been better if they had mixed in live action shots for the humans, because even the humans were looking like toys. NOBODY praised the Scorpion King's CGI in The Mummy 2 when it came out. When The Rock first showed up, I remember laughter in the theater. It was so bad, at the time. When Final Fantasy VII first came out, most gamers were wowed by the graphics, because there had never been anything like it before. But it was the pre-rendered cinematics and background art they were wowed at... nobody was impressed by the potato people running around on top of that background art, nor the PS1 graphics engine's texture rendering that made textures shift randomly and look all pixely. That stuff irritated the hell out of me at the time (especially in games like Tony Hawk, where walls seemed to jitter as the camera moved). And nobody thought the cinematics in FF VII were *realistic*, just that they were cinematic in a way console games couldn't be before. It felt like console games were starting to enter the big league. When Mario 64 first came out, I remember feeling ripped off because the in-game graphics didn't match the promotional material. His hands were all blocky and weird. The levels were tiny and very obviously constrained by memory limitations. I remember thinking all of that *at the time*. It was cool having all that free-range ninja-like movement, but the graphics themselves felt like... a prototype. Zelda 64 mainly added three things over Mario 64: Cinematic camera work, higher-resolution textures, and larger regions. You could get *fairly close* to a character before you could start making out the pixels in their eye textures. Certain scenes, like the intro to the [Morpha boss battle]( URL_0 ), felt like movie-quality camera work compared to earlier N64 games. During the N64/PS1 era, I remember feeling like the graphics in games took a big step *down* from SNES in certain ways. In the SNES, graphics were meticulously designed with pixel precision, but the N64 and PS1 were so graphically limited that everything just felt like *polygons trying to resemble characters*. Everything felt lumpy and ugly, and it wasn't until the Wii era that I felt games looked truly *good* again.",
"People get jaded and always want the bar to be raised. If you look at some of the \"terrifying\" horror movies of the 40s-60s a lot of them are positively comical, yet were well received by the viewing audience. Now, people require more and more to be scared. Same with CGI - more and more realism is needed, although it can be considered a mature technology now that entire cityscapes and fully-believable creatures can be plausibly created in CGI-space. Star Wars' CGI was panned when they first started using it, now they make fantastic movies that almost exclusively use CGI for special effects and creatures. I remember when \"The Last Starfighter\" came out in 1984- I was completely blown away. It was the first movie to use CGI to simulate real-world objects (as opposed to the computer world of 1982's \"Tron,\" which IIRC was the first movie to use CGI of any kind.) Movie sites talk about the months of rendering on Cray supercomputers and similar feats used to create LSF's CGI scenes. However, by today's standards the graphics in LSF look rather crude, almost cartoonish. (Would love to see a reboot with modern CGI...)",
"Medium of delivery changes with time and this leads to an unjustified evaluation of old cgi. Ofcourse new cgi is way better than old cgi but if you play a 480p movie at a 4k tv it will look like shit. You have to remember that old cgi was supposed to be watched at tv that is 360p or lower resolution and with washed out colors. Also this is not only true for movies or tv shows. Same phenomenon is true for video games. When you play old games in a new monitor it looks disgusting but the same game played with an old monitor which the game is meant to be played at the time of release looks pretty decent.",
"Something I have not seen mentioned is the transition from analog storage formats to digital. Or how every time you encode and process a video, you lose quality. Converting a video from an analog format to a digital format introduces errors. Further complicating things, when that digital copy is re-encoded for transmitting it is again lowered in quality. Depending on how the viewer is actually viewing the content, there may be *hundreds* of re-encoding passes made before they see it. And the older content that was converted in the beginning is utter rubbish quality. As far as old video games looking like crap now, looking back... well, that's because the human mind is the ultimate gap filler. Your imagination gets engaged when you *remember* something. Your mind just glossed over all the imperfections in the moment of excitement while playing.",
"The audience learns what the tell-tale signs or artifacts of the effect are. 2018: \"The video is a fake. It looks like a PlayStation 2 game.\" 1998: \"What's a PlayStation 2?\"",
"It is like going to the eye doctor. \"Wich one of these slides is more blurry\" they ask, they flip slide 1 and 2 and 3 and 4. You thought those were fine untill you compared them too 5 and 6.",
"No, they never looked real. Even today, they don't look real most of the time. They look great, but usually not real. The first \"real looking\" CGI I remember is Lieutenant Dan Taylor's legs, actually the lack thereof, in Forest Gump. That effect looks as good today as it did then.",
"The resolution of the screen makes a big difference. I remember being really impressed by the cave of wonders in Aladdin as a kid, but then years later, it was a let down to see how fake the CGI looked. That is, until I saw it yet again on my parents super old square-shaped tv. With the resolution on that thing, nothing was quite as crisp, so the CGI in the cave just blended in naturally with the rest of the movie. It’s like when you use a soft lens or put a pic in photoshop and blur it a little. It’s definitely not a good, sharp quality anymore, but the lack of sharpness disguises the imperfections.",
"When people say soemthing look real they don't necessarily mean it in literal sense, come on...",
"It's because it never looked that great to begin with and we just accepted it because we were comparing it to other CGI. I remember hating N64 games because the graphics were so shitty, even at the time.",
"Our standards are raised over time as things get better, the jump from SD to 720p was absolutely massive for visual mediums, but now we look at 720p like we used to look at SD, anymore SD is a joke because of the low resolution.",
"People confuse looking semi-realistic with realistic. For example, in Rogue One the animated Tarkin was an impressive job, but he did NOT look real. In 10 years it will not hold up.",
"As far as video games: You used to play them on Standard definition TVs. PS2-level graphics looked real on SDTVs -- or at least as real as anything could look on them. They do not look real on HD-TVs",
"Because you are judging relative to other CGI. It never looks \"real\". It looks \"better than you expected\".",
"Standards change. Simple. “Oh that looks real!” Becomes less real as time advances, then you realise it wasn’t so good to begin with",
"Something other people haven't addressed is increased resolution; CGI made for a standard definition release looks garbage on a HD monitor, it's the same for HD to 4K too.",
"I remember reading something a few years back about how absolutely horrified movie goers were back at the start of cinema, like there was some scene with a train that went towards the camera and people were scared out of their mind because they thought this super grainy black and white train come to run them down Everything looks real until we have something real-er to put it up against",
"It’s all what you are use to seeing. I wouldn’t say they looked real back then, but we were use to it’s look and accepted it. Some movies, like Avatar may have been technologically impressive for the time but can’t compare to today’s big budget CGI. Even in this day and age, subpar CGI jumps out as extremely noticeable. Most recently was Hela fighting the asgardian army in Thor Ragnarok. Her movements had a rubbery look to them that was subpar for a Marvel movie. Let’s not forget about the infamous Superman jaw from Justice League.",
"I want to know the answer to this one too. I was thinking about the other day about video games more so than movies. When 007 goldeneye came out it was amazing. Looked so good! 2018 I have a ps4 pro and have been playing horizon. Which today, horizon looks absolutely stunning. Only to be beat by the last of us 2? But. Will these games look like absolute shit in 2035? If you play goldeneye now. You can’t make out a facial feature. There wasn’t enough memory to have a good world. But today’s games you can. So will these games age better? Uncharted 1 for ps3 looks like shit. So probably not.",
"This answer is going to get lost but... I can think of a short list of reasons. 1. You are not comparing a 2D image to reality and not a virtual one to reality. You are actually comparing your expectations of 2D art to the 2d art from before. (I heard people saying graphics couldn't get better back when the 360 came out, I laughed at them then too but it's a good illustration.) Your expectations were tempered from the crap you saw before. 2. You have additional practice with better and better effects training your eye to notice things like light and texture as the artist's tool box expands. 3. Selection bias. Watch the Scorpion King and tell me The Rock looks real. Even back then they didn't. But the good movies had short cuts and were not over ambitious, these are what you are remembering. People made a big deal about the stained glass golem in *The Adventures of Young Sherlock Holmes* yet no one remembers it now. 4. Higher quality mediums. Back in standard quality artists could add a .2 pixel blur to everything and get away with it. Now with remastered videos all of the imperfections get shoved in your face."
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87t95r | encoders, decoders and transcoders | Technology | explainlikeimfive | {
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"Encoder - changes data into a certain format or \"code\". Usually it's to conform to certain standards for displaying the information, such as ASCII being the standard for displaying letters and symbols on computers and other devices, or .mp3 being a common format for audio data. Decoder - changes the encoded data back into it's original form Transcoder - changes encoded data into a different code, which is generally faster and more efficient than decoding it and re-encoding it to the new format (although in some cases, that's all you can do).",
"A human example: Encoder: hear someone talking, write their words down on paper Decoder: read words from paper out loud Transcoder: Read words from paper, type into computer without moving your lips. Or alternatively, transcoder: Read words from paper, translate into French & write down on new bit of paper."
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87u8ea | In a game program, do bullets check if they hit an enemy or do enemies check if they are hit by a bullet? | Technology | explainlikeimfive | {
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"Most game engines have a collision detection system like u/jaksblaks said. It is the reason why characters don't go through walls and don't fall through the floor (not in a Bethesda game though). Weapons in games that use physical projectiles like bows or grenades work under these collision rules and individual projectiles are rendered and thrown in the game world, but bullet-based guns work differently. They use hitscan calculations. Basically, whenever you click your mouse and shooting animation plays, a straight laser-like line goes through the map where you aimed and calculations are made detecting weather you hit a wall or a person or whatever. There are some problems with that system in online games though. Your shots and whats going on on your screen locally gets prioritised over whats happening on the server and on other peoples screens, basically frustrating situations occur when you run past the enemy behind the wall but get shot by him even though you ran away. This happens because on his laggy machine with he shot you, data got send to the server and game goes: \"Oopsie daisy, apparently you was supposed to be dead\". This wouldn't happen if the bullets were physical objects that were rendered in game and were processed by server equally for every player. Why not use physics based bullets for more realism though? imagine 64 player match where every player uses machine gun. Its like 500 bullets per second to process, online gaming servers are already pretty crap, this would make them explode. If my english was gibberish just watch this simple [video]( URL_0 )",
"either way is acceptable, but the answer to your question in general is probably neither. something like this is called collision detection. it's a separate algorithm that keeps track of everything and checks to see if anything hits anything else, what it is, and where/what it hit.",
"there are two ways that games check if a bullet hits, the first is to have a bullet object that moves with physics, and then as it travels, the game checks if the bullet and the player's model are in the same place at the same time. The most popular method is called hit scan, and it's used for most guns that have a non visible or very fast projectile(in the later case, any projectile animation is not actually an object that does anything, it's just a visual effect to inform you about the result of the hit scan). Basically, the gun calculates the path a bullet would take, and then if there is anything in that path, it gets hit. It takes significantly less resources to do a single trajectory then to simulate a bullet object, and this is what many games do to improve performance, using it where you're not likely to notice the difference fort he weapon in question. So far as the logic is concerned, you can have the function that checks for a hit be attached to a bullet object, the player and target objects, or just as a function of the environment, it's up to the game creator to define these things."
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87vfx2 | When Wi-fi signals are passing through walls, what’s really happening at a subatomic level? | Technology | explainlikeimfive | {
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"We can ask a very similar question: \"When light passes through air, what's happening at a subatomic level?\" Every material out there is transparent to some wavelengths of light, opaque to others. For example, infrared radiation does not get very far through air, despite air being thin and transparent to our eyes. If light fails to pass through a surface, it does so either because of reflection or absorption. Both processes involve something similar at the atomic level, which is light interacting with electrons. The wavelength of a photon corresponds to an energy level, and electrons will only absorb photons at particular energy levels (due to their atomic and molecular structure). But if there are no energy levels in a material matching the wavelengths of incoming light, the light will pass through. This works for visible light, wi-fi, gamma rays, and all wavelengths in between.",
"The photons (radio-wave WiFi signals) are \"missing\" the electrons in the atoms in the wall, and passing through it. The wavelength/\"size\" of the signals (or the frequency/\"time\" of the signal) is too different from the material in the walls to be absorbed. Mostly."
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87vzjp | Why are cameras mounted on planes used for the various militaries around the world such poor quality? | Technology | explainlikeimfive | {
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"They're generally very high quality; they just have poor optics and low resolution because they're designed to always work under any circumstances. Poor optics is caused by glass tolerances required, and low resolution is due to the energy and emissions constraints they need to comply with (you don't want someone stealing your milspec video feed).",
"They're very high quality. The images or footage you are seeing is not the same that a drone pilot or an F-16 pilot is seeing in flight. Also, different cameras are meant to do different things. A camera meant to identify a person's face from a drone at 15,000 feet is going to be a very good camera, but those things are almost certainly highly classified. Then there are cameras meant to confirm airstrikes hit the designated target, potentially at night and through cloud cover, which means infrared, which means they need to be rugged and work all the time. These are the images and videos we usually see."
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87w2p1 | Why can YouTube handle having millions of hours of video uploaded Perday. But Netflix has to delete movies and TV shows | Technology | explainlikeimfive | {
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"Netflix doesn't delete their movies and TV shows because they run out of room. They delete them because they don't own the content, and only rent it, basically. so when the contract is up with a certain show or movie, and Netflix either doens't want to pay again to keep showing it, or the two companies can't reach an agreement, they just don't show the content anymore.",
"Because they probably lose the streaming rights to it or they possibly only paid to stream that specific movie or tv show to stream for an amount of time.",
"Has nothing to do with storage or technical issues.... its to do with licensing of content. Youtube hosts either copyright material uploaded/provided by the original creator or licensee, or self published material or material that has been altered under some appropriate right to free use model. If you upload something like a movie to Youtube, they can and will enforce a takedown notice from the original rights owner. Netflix hosts content that _they_ have to license from the original rights owners. Each year, and _PER_ geographical region, Netflix has to negotiate and pay each content producer or distributor for the right to broadcast their shows. All of this costs money. Fortunately they have detailed stats on how many times each show gets watched. If a show isn't getting eyeballs, they won't keep that show around next year unless they get it for free."
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87w9ib | Is there a wire going through the clear spiral tubular earpieces or how is the sound delivered to my ear? | I have to wear one of the clear spiral earpieces at work to communicate through out the hotel. These earpieces (like the ones the Secret Service wear) and it looks like an empty tube. If that’s the case how does sound just go through the tube like water or is there a invisible wire going through it? | Technology | explainlikeimfive | {
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"No wire. One end of the clear tube goes into a earpiece in your ear. The other end goes into a box that you clip inside your clothes. A tiny speaker in the box makes sounds, and the sound travels through the tube to your ear where you can hear it. The technique started before tiny earbud speakers were developed, and it remains for some folks, like the Secret Service, because it prevents the discharge of their firearm from deafening them in their earpiece ear.",
"> and it looks like an empty tube. It is an empty tube. Well, more precisely it is full of air. > If that’s the case how does sound just go through the tube like water or is there a invisible wire going through it? It goes through the tube in what should be a more understandable way than it going through a wire: It is sound. Sound is compression waves in air and the tube is full of air. If you push air in one end of the tube it must come out the other, and if you pull air out of one end it must come in the other. The mechanism works then by attaching a speaker sealed to the other end of the tube which will vibrate the air, and the other end of the tube goes into your ear. Effectively it means the speaker might as well be right next to your ear."
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87woj0 | Why can’t Snapchat prevent screenshots in a similar way to Netflix? (It makes the picture black) | Technology | explainlikeimfive | {
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"I don’t think they’d want to block the ability to stop screenshots, they just let the other person know that it was screenshot in case it was a......sensitive snap"
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87wpjw | How can you determine the difference in properties (hardness/toughness/ductility etc) of different steel microstructures? | By microstructures, I'm talking austenite/bainite/martensite/pearlite etc. Taking a materials engineering class, and I don't understand the current office hours explanations. | Technology | explainlikeimfive | {
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"At the 10,000 foot level, basically the smaller the components of the microstructure, the harder, less tough, and less ductile the bulk sample will be. The Hall–Petch relation tells us that smaller grains are associated with increased strength. Toughness and ductility are basically similar parameters, especially when you are talking about a single family of alloys, like steels. And, generally speaking, stronger alloys will be less tough and ductile. The same mechanisms that allow them to resist yield mean that they will break more quickly once they start yielding. Again, this is extremely high level and is not universally true. For various steel microstructures, there is the additional wrinkle that certain microstructures are generally isotropic while some are lamellar. Could you go into more detail about exactly what you aren't getting?"
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87ykob | How has my phone (and other phones belonging to lucky people) survived falling onto hard floor without even a crack? | Technology | explainlikeimfive | {
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"Glass is surprisingly a lot stronger than most people believe. The reason glass shatters or cracks from impacts is usually due to imperfections in the manufacturing process. These imperfections are often too small to see with the naked eye. Depending on how precisely it is made, there will be more or less imperfections. These imperfections give a weak point in the structure so when it receives an impact, that is the first area to fail. Since glass is very brittle, once a single area is compromised, the crack tends to propogate (spread) quickly and even shatter. It's like how something is easier to rip once a notch is cut in it. The force required to propogate a crack is much less than the force required to cause a material to fail on its own. There are very well engineered glass cups that are made to have minimal imperfections that you can easily drop from above your head onto a hard floor without shattering or cracking."
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87ypj4 | What is General Data Protection Regulation (GDPR)? | And why does it matter | Technology | explainlikeimfive | {
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"The GDPR is a europe-wide regulation to make sure your personal data(like e-mail, phone number, address, your phones GPS-location) stays safe. Not being compliant with the GDPR means risking a fine of 4% OR 20 million Euro(whichever is higher), or 2%/10mil, depending on how badly you fucked up. It is enforced from the end of may, that's why currently it's a issue for plenty of companies. It's not just data control, it also enforces a few rights for users: - the right to be forgotten; have your data deleted on your request. - the right to see or change(rectify) your own data. - the right to be notified when a company leaks your data. - the right to object to certain processing of your data(for example, an automated system that doesn't take your full situation into account). - the right to request your data as something that can be read across machines(not necessarily Excel-sheets, but certain standardized formats such as .json, .csv, or .xml files.) Data here can mean anything that leads back to you; e-mail addresses, date of birth, phone number, usernames, GPS-locations, etc. It also means having to click that \"Yes I'm okay with your privacy statement\" every damn time, because saving information about you consenting with a companies' data collection is also part of the GDPR."
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87yr8r | - why do devices perform poorly when they're working with an unstable internet connection? | This happens to cell phones and computers alike, and different devices often with the same internet, or the same device across different unstable internet connections. This can often affect programs that don't use the internet, and even programs that do use internet (like Chrome) will take forever just to load before you get any indication of service. | Technology | explainlikeimfive | {
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"**TL;DR**: *Devices, particularly ones with badly designed programs, are often doing multiple things that require a single communication request with your network to be fully answered before they can finish, and when that doesn't happen due to a bad connection it can clog things up.* - - - Imagine you need to have a long complex conversation with someone with a very serious stutter and is very nervous. The matter is important but you have nothing to write stuff down, so you're limited to asking and answering questions verbally. So you ask your question and, try as they might, they try to answer it, but a combination of their speech challenges and the complexity makes it really difficult to get all the answers, and their anxiety makes it worse. Eventually the communication may become so frustrating at some point that things start getting forgotten or it just gets stuck. The more patience you both have, the better it goes, but even then things can jam up and you're both left hanging. And the more things you have to talk about, the worse it gets. Well, that's kind of how a bad internet connection can work. Internet connections are designed to compensate for such burps and fits and starts. The data that's transferred between your local device, you home's internet router, the equipment and communications lines out there in the internet, and your destination all send information with error-checking and error-correcting stuff built right into them. But that isn't perfect, and the more time the programs on your local device spend error-checking, the less time they spend actually trading information. In some cases, particularly with badly designed programs or ones that rely on other programs, it can be so bad that an unexpected condition can happen and it just plugs up the local device. Sometimes this is because one thing that it's trying to do ends up blocking another thing it's trying to do, and sometimes it's because something completely unpredictable \"breaks\" the program that's trying to handle the communication. So that program \"freezes\" and leaves one of those conversations hanging... while preventing all of the others from finishing too. And then you curse and take the battery out or reboot the router.",
"If a device is on an unstable connection, the delay you experience could be: * the overhead in [re]establishing the connection * the data you are asking for isn't getting to you"
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87z8y0 | Did Apple and Windows both skip the "9th update" coincidentally or is there more to the story? | Technology | explainlikeimfive | {
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"iPhone 9 got explained by different comments, but the actual story behind Windows is far more interesting. It seems due to some sloppy programming, there is a bunch of MS applications which are checking the version of OS by verifying if it begins with '9' (to differentiate between Windows 95/98 and later versions, which have a different architecture). So they had to skip Windows 9 because of the risk it would be accidentally treated as an old Windows version by some apps, causing compatibility issues.",
"I can't speak about Windows, but Apple has been doing this for ages to make their phones seem as advanced as their competitors (chiefly Samsung). There's no iPhone 2, for example; they went directly from the original iPhone to the iPhone 3G. With regards to MS, it would make sense; they did a similar thing with the Xbox (which competed with the PlayStation 2) being followed by the XBox 360 (competing with the PlayStation 3). Of course, then they went full circle with the Xbox One... It's very possible that whoever is in charge of naming things at MicroSoft has no idea how counting works...",
"Coincidence. iPhone 9 still might happen, the X is sort of considered a different line-up versus their numbered series. More likely than not, the next iPhone with a physical home button would be called the 9.",
"A rumour started going around the internet as to why Windows skipped 9, which was some shitty programming to tell if the windows edition started with 9, then run for win 95/98. This is a lie. At Microsofts first Windows 10 briefing they said they wanted to do windows 9, but it was \"too much of a technological leap to just go up one number\". They also considered calling it Windows 1 to fall in line with their other products (Xbox One, OneDrive, OneNote etc) but then they realised Windows 1 already exists so they went with 10.",
"I’m sure their marketing teams have done in depth analysis to determine that the number 9 won’t sell well. Maybe they figure people would rather wait for the 10. I think it’s generally seen as a more significant number, and people might assume there will be a landmark tech leap with it or something.",
"The iPhone X was the 10th anniversary special edition model, not the next iPhone in the regular release sequence after the iPhone 8. [Their regular release schedule is about a year between new models]( URL_0 ) and the X came out about a month and a half after the 8 was released. There will most likely be an iPhone 9 later this year."
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880xic | Why are there thousands of photos of distant galaxies, but few clear shots of planets in our own solar system? | Especially surface shots. With a powerful enough zoom why can we not get any relatively close shots of Venus' surface for example? | Technology | explainlikeimfive | {
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"Galaxies are huge and contain billions or of stars, each of which gives out as much light as our own sun. Planets on the other hand are small and don't give out their own light, they only reflect light from the Sun. Besides, we have plenty of clear pictures of every planet in the solar system. The only exception (which isn't actually a planet) is Pluto because it is so small and far away.",
"Galaxies are fucking massive. Literally unfathomably massive. So massive, that even ones 50,000 light years away are larger than Pluto in relative distance! That basically explains it.",
"Galaxies are very large objects. The planets in our solar system are not, relatively speaking. For an idea of scale, the Andromeda Galaxy, 2,537,497 light years away occupies 3 times more space in the sky than the full Moon, 1.2 light *seconds* away. Additionally, many of the bodies in our solar system are quite dark, while galaxies emit their own light, and as galaxies are much further away, their movement across the sky is less than that of objects in our own solar system.",
"It's all about *apparent sizes*. As you know, objects look smaller when they're far away. Galaxies are much farther away than planets, they're much much much MUCH MUCH bigger. (That's not enough muches, to be honest.) Here, I made you a demonstration: [This picture]( URL_0 ), from Astronomy Picture of the Day, shows how big in the sky the Andromeda Galaxy appears from Earth, compared with the moon. (It's a photoshop, not an actual photo, but the apparent sizes are right.) Mars is just a bit bigger than the Moon, but it's it's hundreds of times farther away. I've edited the photo to add Mars on there too, with the correct apparent size. Do you see it? I put it in an obvious place..."
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883e7b | How works a SysReq key on keyboard? | It should work even if the computer is frozen, right? Which operating systems support this function? Why do modern keyboards still have this button? | Technology | explainlikeimfive | {
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"> It should work even if the computer is frozen, right? Depends on how it's frozen. Some crashes crash the kernel as well. > Which operating systems support this function? [Linux does]( URL_0 ). See the link, which includes a list of things it can do. Windows as far as I know doesn't do anything with it. > Why do modern keyboards still have this button? It's combined with the \"print screen\" key. So long that is there, sysrq is just more text on an existing button. Nothing else is really needed to support the key. Keyboards just send messages like \"Key #20 was pressed\", what that actually does is entirely up to the OS."
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883mhn | what technology did NASA use when sending back pictures from Pluto? | Technology | explainlikeimfive | {
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"New Horizons was the 2015 mission which sent us lots of pictures from Pluto, and it communicated with Earth through high-frequency (7-12GHz compared to Wifi's 2.4GHz or 5GHz) X-band transmitters that sent data at about 1kbit/sec. This was sent to Earth and picked up by NASA's Deep Space Network of satellite dishes in California, Australia, and Spain. Those locations were chosen because they are about 120 degrees apart on the Earth's surface so it can pick up transmissions from anywhere in the Solar System regardless of Earth's rotation. edit: word",
"On earth you need large antennas in the NASA Deep Space Network to receive the signal. The transmitter is 2.1m high gain antenna(highly directional) with a power of 12 W. They uses antennas with dishes that have diameter from 34 to 70 meter to receive the signal. You can read more about it at URL_0",
"There are two big, special parts of the many which make this possible, and they're what really makes it work over such a long distance. ###Directional Antenna Imagine the probe is a flashlight - a Maglight. The bulb is the radio transmitter. A transmitter like an FM radio station puts out signal in all directions - like if you take the top off the Maglight and use it as a lantern. A directional antenna is like putting the end back on the Maglight - now light points only in one direction, but is brighter. The antenna on the Pluto probe is *very* directional - like making the light of a Maglight focus on the head of a pin. All of the signal goes only in one direction. To add to that, the antennas NASA uses on Earth are also directional - they \"listen\" to a very small area of the sky but they listen to it *really hard*. If you had friends living in the country they might have had a TV antenna with a rotator so they could pick up farther away stations in different directions - same idea. ### Error-Correcting Signal The signal the probe sends back to Earth has built-in error correction. It sends the picture back as data, just like looking at a file on Imgur. Because it's so far, it can only do it very slowly, but the data is grouped together with a checksum. A checksum is a number at the end of some data that is not actually part of that data, but is used to make sure what the receiving side gets exactly matches what is sent. It does that by doing some math on the data in that group and then coming up with a resulting number. NASA does the same math, if their number matches then the data is all good. If not, then something was mis-received. If it's not a big change, NASA can guess what part went wrong and re-check to see if everything now matches. Because Pluto is very far away and the amount of data that can be sent at a time is very small, it's likely the Probe also sends data multiple times as well, so if one group is lost or changed too much to correct, NASA gets another chance to receive it. Think of error correction as proof against a game of Telephone - what the first person whispers to the second would be exactly repeated at the end."
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885rna | Why do video games play smoothly in real time but animations can take hours or days to render, even if the game is more graphically pleasing? | Technology | explainlikeimfive | {
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"Games take lots of shortcuts, and will probably never have the level of physics some animated movies get. Disney's movies are insane sometimes. They have crazy accurate physics for snow and even have animated each strand of hair individually for more realistic looks.",
"If a video game is rendering at 60fps, it will be rendering a new frame every 16.67 milliseconds. That's not much time at all. Cinematic-quality rendering is likely to include calculations that take far longer, such as: - Depth of field, which simulates the effect of a camera lens focusing on certain objects in the scene - Global illumination, which calculates light coming from light sources *and* light bouncing around between objects in the scene - Ambient occlusion, which calculates how much each part of each object is exposed to ambient light in the scene - Deeper physics simulation, including cloth and hair, soft body simulation, far more elaborate particle effects, and so on - Reflections, where shiny surfaces allow you to see the reflection of other items in the scene Games do approximate some of those, but they take a lot of shortcuts to save time. If you can afford a few minutes or hours of calculations per frame, you can do all of these things at a much higher level of fidelity.",
"Video games take shortcuts; sometimes heavy on some post processing technique, or other times a \"cheaper\" method to achieve the same effect as the big budget \"takes months to render\" works. It's comparable to something like a weekly comic strip to a book. The weekly comic strip has to work to pump out the material on a pretty fine & rapid schedule - a long running comic might have as much content as a book, but the book might have taken as long/longer to produce that single book compared to a single comic. With video games & animations, it mostly comes down to how high they can crank the quality - a simple analogy is that a video game tends to have limited texture sizes; but the \"takes eternity to render\" animations would have a much higher texture size available. Except this difference in quality applies to pretty much everything (ie: render all the hairs, not just use a few polygons & textures).",
"Basically, to get 60 fps video games cheat, they cheat like a motherfucker, they cheat in every conceivably way No game bothers with calculating the movement of individual hairs, if they have any hair physics at all. Elsa from frozen has 400k hairs. for reference, a human on average has between 150k and 90k depending on hair color, (this is part of why replicating her haircut never quite works out) Water? games hardly bother with water unless its a major focus in the game. rendering a single source of reflection doubles a frame's rendering time, so mirrors frequently don't work, and if you enter an area with many reflective surfaces they only render blurs or cheat with pre-renders Clothing is another good one, almost no video game character has clothing that realistically moves and interacts with the surroundings, it clips all over the place, that's cause calculating on the fly how a dress realistically flaps in the wind is just not feasible",
"Films are mostly ray traced. Ray tracing looks at each pixel in each frame and traces the light ray for each pixel back to its source to figure out what color and how bright that pixel should be. Ray tracing produces the highest quality and most realistic results but at a tremendous computational cost. Last I heard, it's generally accepted that real time ray tracing at high resolution just isn't feasible. GPUs, the specialized hardware that makes games look good, use fancy math and some observations about how we perceive things to cut corners in drawing each frame. This allows games to run at high frame rates at high resolution, but the trade off is... well, reality. For instance, a ray traced mirror requires no special handling, while a GPU handling a mirror might need to be programmed to reflect a player's face, but only when a player is looking at it, and otherwise just make it look shiny. All that said, why one game or animation looks better than the other often comes down to the skill, time and budget of the people putting it together."
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88a0hh | What is rendering in CGI | Technology | explainlikeimfive | {
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"On the computer, the animal is just lines of code. Instructions for generating objects, where those objects are located, and what parts of objects can be seen, and such. For example the information needed to draw a sphere is just two pieces: a point in space plus a radius. Rendering is the act of taking all of that information and actually constructing what the seen looks like (from a certain point of view, with given lighting, etc.) Rendering can take a long time, depending on the complexity of the scene. A movie has 24 frames per second and it can take anywhere from hours to a few days to render a single frame."
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88aa91 | What does it mean when a film is "remastered"? And how do they do it? | Technology | explainlikeimfive | {
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"Remastering a film can include audiophonic, cinematic and/or videographic improvements. The term \"remastering\" typically refers to taking the \"master\" release of a film (the final version intended for end user or audience consumption) and transferring it's elements from an analogue to a digital medium. Digital audio provides a clearer and crisper sound, and allows for the introduction of new sound mixing elements. (A 50's film used a metal sheet to create a thunder sound effect and is remastered to include an actual recording of thunder.) This process can also include adjusting dialogue decibel levels and adding surround sound/immersive audio capability. Cinematic and videographic remastering usually involves scanning the actual film, one frame at a time, at no less than 2K resolution. (More recently films have been remastered at 4K and up.) This allows the use of software to artificially enhance and/or filter lighting, as well as remove any signs of damage that would have been seen on a reel - dust, scratches, oils, etc. Today, the process also allows for addition or subtraction of elements via CGI and animation. See the scene in the 2002 remastered version of Spielberg's E.T. where guns were replaced with radios."
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88az0c | Why do current video games need o be patched/updated constantly? | Technology | explainlikeimfive | {
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"text": [
"Because programming games is hard work and no amount of QA testing will catch every bug and every balancing problem"
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88bwny | Why does the video feed cut out when a Falcon 9 lands on the drone ship? | Does the satellite link get disrupted or does the camera just not tolerate the environmental conditions? | Technology | explainlikeimfive | {
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"text": [
"The satellite link gets disrupted. You have to aim the antenna at the satellite, and that is rather hard when something [this big]( URL_0 ) is landing right on the platform."
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88coll | How do video games know when a bullet hits the opponent? | Technology | explainlikeimfive | {
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"Depends on the game. I believe games such a battlefield actually send a bullet projectile and just record the position of contact on the player. I might be talking shit but that's my best guess.",
"That's dependent on the game as well as the gun in question. In COD for example, all guns are hitscan. There is no bullet drop, no travel time. If your crosshair is on an enemy and you hit fire, the server registers that as a hit. For games like Battlefield, many guns (particularly snipers) have their bullets treated as projectiles. So firing your gun creates a physical entity in game that travels at a set trajectory/speed that, if it collides with an enemy player model, is registered as a hit."
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88dfjq | How can my phone have 6GB of RAM but my PCs 8GB RAM sticks are bigger than my phone? | Technology | explainlikeimfive | {
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"There are different considerations taken in mind when both are manufactured. RAM for your phone has to be small, light, and efficient. PC RAM isn't constrained by those, so it can be bigger - which makes it significantly less expensive - and it can use as much power as it needs to - which makes it faster. That also makes it hotter, so it *has* to be bigger to have more surface area to dissipate heat. Your PC RAM is also interchangeable, since it's not built into the motherboard. It's the same question posed to laptop manufacturers: why is RAM designed for laptops smaller and usually more expensive? Well, smaller makes it more expensive, and it has to be more power efficient. Your phone's RAM is built into the board, it uses more expensive smaller parts, and it isn't as powerful."
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88fvou | How do games run out of memory? I know that Pac Man reaches the kill screen when one half of the board runs out of memory,but how does it happen?? | Technology | explainlikeimfive | {
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"The kill screen in pacman doesn't occur because it runs out of memory, it happens because of an integer overflow. The game keeps the current level stored as a single byte integer. A byte can hold a number between 0 and 255. When it passes level 255 is increments this counter, but instead of reaching 256 it rolls back to 0 - that's what the \"overflow\" means. The game code however doesn't know how to handle \"level 0\" (the code assumes the level number is 1 or larger) which causes it to malfunction. A more in-depth explanation can be found here: URL_0",
"Memory used to be very expensive, even a few kilobytes of RAM would increase the cost of hardware like an arcade cabinet by a lot. The Atari 2600 for example only had 128 bytes of RAM. That 1/8192 of a megabyte. So programmers had to be very stingy and very clever with how they used system memory. So a game like Pac Man only had a single integer (8 bits) allocated to the level counter. Because 2^8 = 256 possibilities ( 0-255 ) is more than enough possibilities for an reasonable game of Pac Man. The problem is what happens when you reach level 256? The counter resets to zero and the game basically crashes because it doesn't know how to handle level 0, and the extra bit that got added (representing 256 in binary requires 9 bits, when only 8 bits are allocated) has to go somewhere so it overwrites something else that's already in the adjacent memory."
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88g70o | How does wifi work with multiple devices? | Is the speed split evenly? is it downloading and sending a certain amount per device like 10kb for you, 10kb for you. Does my streaming a movie slow down others while it focuses on large files, or does it slow it for me as well evenly? Is there a limit to amount of devices? How does it know which device to send the next packet of info to when there are many connected.....so many questions, please ELI5 | Technology | explainlikeimfive | {
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"Imagine wifi like a post office. Each device connected is like a different customer. It has a different name to the others and has its own little box items get sent to and from. There is a team of workers called “Bandwidth” - these guys move the mail to and from the cargo bay, delivering or receiving packages from customers (devices). Now.. depending on how much they’re paid, the Bandwidth team can only move a certain amount of packages at a time. As a default they try to deliver equal amounts of packages to and from each customer. But there are times when the manager (ISP/Admin) tell the Bandwidth team to put a priority focus on certain customers - allowing them to send off and receive packages at a higher pace than others. The manager/depot also decide whether or not, and what, the limit to the amount of customers they can serve at once. This varies by post office though."
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88gc64 | Why does night vision have a greenish tint? | Technology | explainlikeimfive | {
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"text": [
"The image created by night vision is black/white. Human eyes are most sensitive to green light. Since you're in the dark and it takes your eyes time to adjust to light/dark, you only want to make the image as bright as necessary. So the image is given in green to make it more comfortable to view in the dark, possibly for long periods.",
"The human eye is most sensitive to green light. This is why the Bayer pattern used in many cameras has two green pixels, one red pixel, and one blue pixel per quad. Night Vision Goggles amplify low light to appear green so that the user can distinguish as much detail as possible while keeping the luminous flux (light intensity) as low as possible as to preserve their actual night vision."
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88h0y1 | How does a computer program talk to someone over a phone call? | you know the automatic calling system that says "Press 1 to confirm" or "Press 9 for main menu" . How does that read the input I give , over a phone call ? | Technology | explainlikeimfive | {
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"text": [
"Every button you press causes a different combination of tones (beeps) to be sent over the phone line to whoever, or whatever, is listening on the other end. URL_0"
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88h2zs | How do we measure magnetic fields? | E.g. I have a magnetic iPad cover which turns it on every time I open it. How does it know when the cover is opened? | Technology | explainlikeimfive | {
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"The other answers that talk about measuring forces or moving coils around are possible solutions in theory, but not practical in real world applications like the iPad cover. In those devices something called a *hall sensor* is used. This type of sensor uses the fact that electrons that move in a magnetic field are pushed in one direction that is perpedicular to the magnetic field and the motion of the electron (example: electron moves forward, the magnetic field is applied from top to bottom, this means that electron is pushed to the right). This force is know as the *[Lorentz force]( URL_1 )*. The hall sensor itself is a thin metal strip ([sketch]( URL_0 )). We apply a small current to the strip (the direction marked I in the sketch). Since a current is many electrons moving this means that if a magnetic field (arrow B in the sketch) is present they are pushed to the edge of the strip. The electrons get crowded on one side and on the other side are less electrons then usual. A lot of electrons on one spot and less eletrons in another spot is what generates *a voltage* (marked U in the sketch). This voltage is small, but can be amplified and then measured, and gives you an idea if a magnetic field is present and how strong it is. Notes on hall sensors: - they have to be oriented in a way that the magnetic field \"hits\" the metal strip in a steep angle (some angles will not work very well and produce only a small signal). This is not a problem for the iPad use case since Apple can mount the sensor in just the right way. If the strength of the magnetic field is important one can use more than one sensor mounted in different angles to solve that problem since at least one is always getting a good signal. - in application where only the presence of a magnet has to be detected orientation is not that important because you just need to sense \"magnet present\" and \"no magnet present\" and the exact strength of the magnetic field is not that important - in reality hall sensors are a tiny plastic package with all the amplification and other electronics built into them, so that manufacturers like Apple can just put the into their devices like any other IC - hall sensors have a lot of interesting applications like measuring currents (by sensing the magnetic field that is generated by those currents)"
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88hxob | How we can get copyrighted so quickly? | Like just as an example, if I were to put a video on youtube with some music, and if hardly anyone will see the video, yet the audio gets taken down by the company who owns it, like how did they find my video? Surely they don't watch every video that's put on the internet and decide which videos use their music and so on, you know? | Technology | explainlikeimfive | {
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"text": [
"Have you ever used one of those phone apps that listens to the music playing in the background and tells you what it is? YouTube does the same thing. They work with copyright holders & automatically scan new content to see if it infringes on copyrights. There's far too much content uploaded to the site (they claim 300 hours of video every minute) for it to ever be manually reviewed.",
"Anything you create is copyrighted so quickly because most countries adhere to the 1886 Berne Convention. > Under the Berne Convention, copyrights for creative works do not have to be asserted or declared, as they are automatically in force at creation: an author need not \"register\" or \"apply for\" a copyright in countries adhering to the Berne Convention. > [_Wikipedia_, \"Copyright\"]( URL_0 ) What you mean is getting a claim of _infringement of copyright_ very quickly after making the infringement, by uploading something you don't own the copyright for. That is explained in the other answers."
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88i1wg | When a computer game is loading, what’s actually happening? | Technology | explainlikeimfive | {
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"So, computer hard drives and game discs are great for storing lots of data for a long time, but it takes a little while for the device to get the information it needs, especially if other programs are busy with it. If you wanted to spawn a monster in a game, you'd have a hiccup as the game stops everything to go to the hard drive or game disc and create the monster based on the data. And these hiccups would happen every time the game needs to spawn a new monster. To make sure games are always running fast, computers and consoles have RAM. It's stick-shaped piece of hardware with lots of free space, where we can store information that we need to access multiple times, as quickly as possible. So what the game will do is, before starting a level, take all the information it knows it will need for the upcoming level (the types of monsters in it, what the textures are, the music that loops during play, etc.) and copy it from this slower storage space to a much faster one (RAM). That way your game can run stuff and create as many copies of something as it likes without any drop in performance, and your hard drive or game disc is freed up for other uses.",
"Suppose i asked you to dial \"9116644\" on your phone. One way is to look here, \"9\", and press the button. Then see \"1\" and press the button. And \"1\" and press the button. Too slow. Other way is to keep the whole number in mind for a while and just press the fingers one by one. So there's two kinds of storage for data here. The phonebook (or in this case reddit comment itself), and some temporary space in your mind. Phonebook - lookup is slow, but it's pretty much permanent. Temporarily in mind - lookup is instant, but it's volatile, you'll forget after a few seconds Analogously, the \"loading\" in a game, is just the computer loading all the data it requires to show you the game, the music, the 3d models, the algorithms ... Everything, from the hard disk (which is slow but permanent), into its volatile \"in mind\" memory, called the RAM. (There's more levels of memory, actually, so this analogy isn't flexible at all. But it's a start, the principle is the same.)"
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