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bqht4u | - what's the difference between 3G, 4G, and LTE when using mobile data? | Technology | explainlikeimfive | {
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"It is all based on Frequency or speed of the signal. 4G/LTE are at a high frequency/speed, which means more Data per second. This results in the faster speeds. It is more limited by range than 3G. Because 3G has a lower frequency, it can travel further distances albeit at slower data speeds."
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bqmxny | Can someone explain to me ping? The network term. | Technology | explainlikeimfive | {
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"Think of it like a call and response. If I ask the server if it can hear me, how fast does it get back to me? That's what a ping is.",
"The term originally comes from the sonar used on submarines. They would send out a loud pulse of sound (it actually made a 'ping' noise) which would bounce off any nearby large objects. By listening out for echoes, they could determine the range and direction of other submarines / etc. In networking, computers can send out an ICMP ECHO request to another computer, which just means \"Send acknowledgement of this message immediately!\" If you get a response, you know the other computer is alive and reachable. And by measuring the time between sending the message and receiving a response, you can gauge the speed / congestion / distance / hops of the network link between them. In things like online gaming, the game server will send its own version of the ECHO command to the game client, to determine the time delay between the two machines. It can use this information to determine if the player will have a good experience (for instance, connecting to a server halfway round the world could give you a half-second response time, which is far too slow for a 3d shooter to be playable), and it can try to compensate for their specific delay time (known as 'latency') in its calculations.",
"Ping as a verb means to test the connection between your computer and some other computer (or server) on the internet or network. Ping as a noun (as often seen in games, such as 60 ms) is a metric that tells you the round trip time (RTT) from your computer, to the destination, and back.",
"As far as I remember it's essentially the time it takes for you to send data and receive data from a server. The bigger the number the longer it takes for you to send and recieve data. Hence why in gaming people with very high pings have massive lag.",
"The late Mike Muuss wrote the \"ping\" program and named it by analogy to the sound sonar makes for echolocation. The idea is that you would \"ping\" another computer, and you could find out roughly how far away the other computer was based on how long it took for your ping to get a response. Here is his website in which he explains the history of the program, which he coded up in one night: URL_0"
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bqnoqe | How long exposure photography works. | Technology | explainlikeimfive | {
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"Imagine you have a grid of buckets, covered by a retractable roof. If you retract the roof while it's raining, the buckets will fill up with water. Suppose it's only raining over a very small region. Only the buckets under the rain will fill up, while the other buckets won't. Now, consider, what if that small region of rain is moving. If you open and close the roof very quickly, the rain won't have much time to move and only a few buckets will be filled. But if you open it, and leave it open, you'll see all the buckets it passes over will get filled. You'll end up with a trail of full buckets, even though the source was smaller than that area. This is more or less how cameras work, but with light instead of water, and sensors (or film) instead of buckets."
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bqrp45 | Why are Internet and phone companies so closely related? How has their relationship changed over the decades? | Technology | explainlikeimfive | {
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"Over the last 30 years the internet has evolved from using the phone line system to connect homes (dialup), to being offered with cable TV services, to being offered exclusively over cable or fiber-optic. In the same span of time the phone system has gone from connecting every home with dedicated phone lines, to competing with cable services and finally being usurped by cable services. In order for the internet to function, there has to be infrastructure to support it. When the internet was in it’s infancy in the 90’s, using the phone line infrastructure that was already in place made sense. However, the phone line system was never designed to transmit data. Internet modems were developed as a “hack” to convert audio signals to digital signals and vice-versa. As the capacity and capability of the internet grew, the two copper wires designed solely for transmitting one phone call at a time became inadequate and another solution was needed. Cable television providers in the late 90’s realized their infrastructure was far more suitable to provide internet service, despite being designed to transmit video. Cable television has the ability to provide multiple television channels through a single cable, so providing internet service as an additional “channel” was possible with the addition of a cable modem, which could interpret the signal on the internet “channel” as data understandable to a computer. Starting in the mid-2000’s cable television providers began converting their analog cable television systems to digital systems to pack more channels and to provide faster internet service. Around the same time, VoIP (Voice Over IP) services began to crop-up. VoIP services allow audio to be sent over the internet as a digital signal instead of an analog signal on traditional phone line. This spelled the end for traditional phone services for a few reasons. 1) A VoIP service provider does not have to contend with the cost of maintaining phone lines. Their service works as long as you have internet access. 2) VoIP has the ability to transmit several calls simultaneously on the same line. Besides the reduced audio quality (which would be quickly rectified with increasing internet speeds) VoIP could be offered for much cheaper than a traditional phone line. Eventually, cable television providers realized they could develop VoIP software and offer it as a service alongside their cable television and internet packages. With the ability to develop and offer phone service cheaper and bundle it with cable television and/or internet services, dedicated phone lines have become more and more obsolete over the last 10 years. Over the last 20 years, cable service providers have acquired traditional phone systems through buy-outs and mergers. Many lines have been entirely replaced with cable services, but much of the traditional phone system is still maintained in places where cable service are not yet developed."
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bqscvb | What consequences will Huawei Users have now that Google had to revoke their android License? | Technology | explainlikeimfive | {
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"\"Existing Huawei smartphone users will be able to update apps and push through security fixes, as well as update Google Play services. But when Google launches the next version of Android later this year, it may not be available on Huawei devices. Future Huawei devices may no longer have apps such as YouTube and Maps. Huawei can still use the version of the Android operating system available through an open source licence.\" Explanation from bbc news"
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bqw402 | Why do we use teabags but not coffeebags? | Technology | explainlikeimfive | {
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"Ground coffee loses its flavor when exposed to air, while tea does not. If you had a box of 'coffee bags' like you do tea bags, most of the box would taste terrible long before you reached the end. That's why the packaging for ground coffee is designed to seal the product away from air. It's also why coffee enthusiasts often grind their beans on the fly.",
"You can buy ‘coffee bags’ both to stick on your cup and pour coffee over, or to stick in a machine and get cup sized drinks. It isn’t very tasty though. Water needs to flow through coffee grains. If you let it rest too long you get a misbalance of off flavors."
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br22c9 | What is the 0 dB in digital Audio? | Why is it zero if you hear something? | Technology | explainlikeimfive | {
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"dB is a logarithmic scale. Every time you add 10 dB, you make the sound ten times as loud. Every time you subtract 10 dB, you make the sound one tenth as loud. Zero dB is like multiplying the sound by 1: it's just the original, unchanged sound, at it's original volume.",
"dB is telling you how much louder to make something. 0 dB means dont make it any louder. Negative dB means make it quieter."
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br2aiy | Why is latency and bandwith separated? If latency is delay of data, and bandwith is data over time, shouldn't one affect another? If it takes 5s for a car to start, and 10s to reach it's destination, then the average speed would be spread out across the whole 15s. Should this not be the same? | Technology | explainlikeimfive | {
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"Consider conventional mail (via a post office). This a high latency, high bandwidth type of communications. It takes a few days to get a shipment somewhere, but that shipment can contain almost unlimited amounts of data. Contrast this with SMS (text messaging). This is fairly low latency - your text message arrives almost immediately - but low bandwidth (you can't send all that much data). Another way to consider this: Latency is *responsiveness*. It's how long it takes to get a reply once I send a message. Bandwidth is *volume*. It's how much information I can send over time.",
"There are some good explanations here but I’ll add another anyway because it provides a very concrete example. When you connect a hose to the tap and open the valve, the time until water comes out the end of your hose is the latency. Short hose, short latency, long hose, long latency. The thickness of the hose is your bandwidth. Thick hose, higher bandwidth, thinner hose, lower bandwidth. Now, taking a real use case, if you want to fill up a swimming pool what type of hose should you use? Latency doesn’t really matter because you’re only going to incur it once when you turn on the hose. Bandwidth however will make a huge difference to how long the pool takes to fill. Double the bandwidth, halve the time. On the other end of the scale, take a bathroom sink tap. You want to wash your hands. When you turn on the tap, you’d like water now (low latency)! You’re going to incur the latency multiple times a day and it could be a significant portion of total hand washing time if it’s not low. You don’t need much water though to wash your hands, so a relatively thin pipe (low bandwidth) is appropriate."
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br56e0 | How does audio translate into bits in a computer file? | How audio is so unique but when you open an audio file in a hex editor, the audio is comprised of bits. How is that possible? | Technology | explainlikeimfive | {
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"If you think of a digital picture, you essentially have a bunch of tiny, single-color pixels which, when put together, make a pretty good recreation of whatever you take a picture of. The same is true for a digital audio file, it's essentially a ton of tiny \"pictures\" of the audio signal and when you put them together and play them back, it's a fairly accurate and sometimes exact replica of the original audio, depending on the audio format. You have an analog-to-digital converter which takes in the audio as input, and separates it into millions of tiny pieces of sound, often 44,100 times per second. Each of these tiny pieces is an approximate record of the sound of the audio signal during that fraction of a second. When you play an audio file, the computer stitches all these tiny fragments back into a continuous sound which is played by a speaker.",
"Sound is wave, you can imagine it as a line on a graph. Think back to school, you remember that lesson where they drew little rectangles under a curve? They said that the more rectangles you drew the more closer all the rectangles would match the curve. Well digital audio does that. The sounds moves a magnet a tiny bit, they record how far the magnet is pulling. This forms one box under the sound curve. Now they just have to make several tens of thousands of boxes for every second of music. For example, a CD has 44,100 of those boxes for every second. For the human ear that's close enough to the real curve that we recognize it as sound."
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br5khn | What is a bulletproof vest made of & how does that stop a massively fast bullet? | Technology | explainlikeimfive | {
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"To keep it as simple as possible, there are two main types of bulletproof vests; soft and hard. Soft vests are made of woven kevlar. These are tiny strands of extremely strong fabric. They're woven and layered up to create a relatively soft, flexible panel. This stops bullets by slowing them down as they impact the kevlar, losing energy as they rip through the layers of fabric. Think of it like a speeding car plowing into a bunch of buckets filled with water. These soft vests are the type typically worn by police. They're designed to stop most handgun rounds. The second type of bulletproof vest is hard armor. This is typically in the form of steel or ceramic plates. Basically these are just strong enough to withstand the impact of a bullet. Ceramic plates shatter and spread out the force of the impact much like kevlar does, but on a higher level. These type of vests are worn by military. They're designed to stop rifle rounds. Increasingly, police will carry these in their cars as well."
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br6u1x | How does adding 's' to end of 'http' make it protected against hackers? | Technology | explainlikeimfive | {
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"The S stands for \"secure\", specifically it means that the connection between your browser and the website is encrypted using the TLS protocol. The TLS protocol does two things: 1. When you connect to the server, the server sends you a digitally signed certificate. The certificate is used by your browser to validate the server's identity, i.e. make sure that the entity sending you the certificate is indeed reddit and not a hacker pretending to be reddit. 2. After validating the certificate, the client (your browser) and server set up an encrypted connection, so that all the data transmitted between them is encrypted. This means that it is hidden from anyone who intercepts the communication, and that it can't be manipulated.",
"Adding the 's' at the end of 'http' tells your computer to start doing a bunch of anti-hacker things without bothering you. Namely, to start using encryption so the stuff sent is scrambled into a hacker unreadable mess, that both you and the other site can read. Also it checks with another computer your computer really trusts called a Certificate Authority, to make sure the other guy really is who he says he is.",
"Http is giving your friend stuff in a transparent bag, everyone can see what's in the bag. Https the bag is opaque and no one can what's in the bag - it could be anything.",
"Adding \"s\" only tells your computer to use another method in connecting to site if the site set it up. The difference is the connection is encrypted so hackers can't listen in and checks you're connected to the real thing, not hacker sitting on the wire between you and the real thing. There's also an option to check you're really you and not the hacker with your password connecting from another computer, but that is rarely used because it's too much effort for everyone."
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br8riy | Why do some video game and computer program graphical options have to be "applied" manually while others change the instant you change the setting? | Technology | explainlikeimfive | {
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"That mostly depends on game engine's source code. Some are good, some are not so. Usually, resources need reloading when settings changed, and sometimes API requires recreating all objects. Usually when game requires restart to apply some options, that's because game engine need all resources to be reloaded under new settings and it's easier to do it just by restarting than by actual reloading.",
"Think of it like changing settings to your car. Let's say you want to change the pressure of your tires for a rocky road ahead. You would want to stop your car and change the settings of the tires. Other settings like the speed of your windshield wipers you can change while your driving. There are just some things in software that are running so in order to change them you need to stop the program. Edit: Thanks for the silver kind redditor!",
"so much half knowledge in this thread... unbelievable & #x200B; the only valid answer is : Is it possible to do without reloading : YES , always - requires good coding discipline and experienced coders and proper team lead to make sure everyone knows what they need to know. & #x200B; Why is it not done everywhere? : COST - resetting is easier and shorter to code than the \"reset to clean state but leave everything running\"",
"I am no expert so correct me if I am wrong. Certain physical assets such as textures may be loaded from a file so we first remove the old texture and replace it with a new one. Other things are calculated like shadows, so if we apply a more complex algorithm we can get a nicer shadow, we can calculate this on the fly without loading any assets.",
"It mostly depends on how the developer designed the UI to provide a certain experience to the user and also to meet some expectations on how an UI should work. For example if you are changing the style of your character it makes sense to show the change immediately after you made your choice. On the other end if you are changing some settings that require reloading of the interface this might get annoying fast if done at each change so it makes more sense to apply all of them at once and be done with it.",
"It's significantly easier to just shut it down and start everything over. Much less time to program and much easier to avoid bugs.",
"I'm a developer who has programmed a game engine from scratch. The reason some settings can be applied instantly and some need to be \"applied\" is because of how it is coded. It takes extra work to develop a system that is able to change on the fly and still run efficiently. Also like others have said, it is much easier and safer (less likely to create bugs) if everything is wiped from memory and everything is loaded again with new settings.",
"Textures get loaded at full resolution and then downscaled on game load. If you change texture quality settings it has to reload the assets and do it again. Some engines support this well, some don’t.",
"Mostly because of the underlying workings of said settings. Possibly interaction with other settings. Also the different setting could mean a different initialisation value, requiring a full restart. I can give you a simple example that is easy to understand: translations. Some applications can do it on the fly, others require a restart. A common reason for this is that the language stuff is in a dedicated dll with each language on a different dll. Since dlls cannot (or may not) be unloaded it is not (or may not) possible to ditch the resources of the original language.",
"Think of the program like a workplace. Sending out a memo for a price change is easy. You can do that during a workday. That is what it is like to change a simple setting. However, asking all employees to change their uniform to a different one would require a significant logistics planning to perform while everyone is at work. It would require changing rooms, and rotating employees in. Unless you are fine with your business entirely pausing (program freezing) while everyone changes. It is simpler in the second example to just send employees home with a note to come dressed differently tomorrow. Especially if the dress code rarely changes. The clothes are the different variables/functions/resources that would need to be loaded to change an integral setting.",
"Because most game settings are loaded only at the start of the game. If you want to reload new settings again, you must restart the game. P.S I am a game developer.",
"It actually applies to a lot of design of both software and hardware. You'll have some initialization you do on startup. As a designer/engineer/developer, the least amount of additional work needed to support modifying a setting is to just re-run that initialization process. As an added bonus, it's less likely to introduce a bug, since that single initialization process can be tested more thoroughly. Now, if you want to change individual settings and apply them individually, you have to break that initialization up into different sections. You have to pull out all the error checking/handling, all the consistency checks, etc. The amount of development goes up. In short, it's easier to check and apply everything at once. But the user experience is better if you can do things individually and see the results immediately. So there's a tradeoff.",
"lol at some of the answers here it really just depends on how whoever programmed the engine and interface decided to implement them, there's mostly absolutely no constraint sometimes it's more interesting to validate a setting with a function linked to an apply button rather than instantly change whatever variable is linked to the setting ( as sometimes it can mean using a wholly different codepath (switching between different anti-aliasing methods for example, that's an ugly one)) & #x200B; regarding the way people misinterpreted your question (i.e. why sometimes you need to restart the app when changing settings), that's absolutely only due to the programmer being a lazy fuck and not bothering to implement a proper context changing function, so he'd rather write the new config, bail out and reload with the new settings (truly I don't blame them) & #x200B; source: i like writing game engines from scratch",
"It's mainly a user interface design choice. Many graphics settings affect or interact with each other. When adjusting settings, you may need to change several and then apply them all at once to see what the overall effect looks like. If each change was applied independently the instant you made the change, then you wouldn't be able to easily see the difference that your overall selection of changes made. Applying the settings changes all at once makes it really easy to do an A-B comparison between old and new settings. Another reason for the \"Apply Changes\" design choice is that it allows you to easily cancel. The pending changes are staged, and you can easily back out of them without having to reload anything. If the changes were applied the instant you made them, then they would have to be undone in order to \"cancel\" them, and you'd end up reloading twice.",
"The code that actually calculates and runs each of these different effects is quite complex, and they all sit together in even more complex chains. Certain effects can only be calculated after others have been done, and so on. When you fire up a game, it will *generally* only load the code for the effects it needs, and chain them together in the most efficient order, based on what you've got set in the settings. Having the ability to change which effects are loaded once they're loaded, and which order they go in, isn't a simple thing - so some game engines can't do it. Thus, if you go into the settings and change which effects you want, and the game's underlying code isn't smart enough, it'll have to save those settings, and load itself fresh from the start. Other engines are more sophisticated, and the developers have taken the time to allow these chains to be modified after being loaded."
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br98dc | Why is barcode scanning so quick and accurare, but OCR even for digital text is kinda bad? | Technology | explainlikeimfive | {
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"Given the previous answers I have to add the following. & #x200B; Barcodes and QR-codes have been Designed for computers. They have features in place that help with alingnment. Barcodes have built in error checking numbers and QR codes can even have enogh redundancy in them that a computer can compute the correct result from a bad read or a damaged code.",
"Because OCR has to deal not only with different fonts, but also different languages. To further complicate matters, if you're dealing with a camera OCR, you might be holding it at just enough of an angle to distorte it, have a speck on the lens, light might not be good, and so on. Bar code scanners produce light and only have to deal with one style of thing (and even then it can still mess it up and not scan).",
"For barcodes, you're essentially plotting 2 values (black or white) over a line across the bars. Then you \"read\" the information encoded in this string of values. That's an extremely simple task, and there's a convention to the system. OCR on the other hand requires more complex algorithms (ie rules) to recognise patterns in images. Couple that with noise and a large number of different styles/fonts, it makes it more difficult."
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braulx | What exactly are robocalls? Why are they on a surge right now? And why isn’t anything being done to prevent them? | I have a foreign phone number, and live in another country so I don’t deal with it. I don’t understand why it’s such a huge problem in America all of a sudden. | Technology | explainlikeimfive | {
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"Technology has made it inexpensive to build massive call centers in countries that made it difficult to stop with legal actions. The US telecoms are terrible. They have no incentive to provide a good customer experience, so they don't use technology that easily blocks numbers that are masked.",
"Phones and computers both work on signals sent VIA electrical pulses. If you understand how a phone dials a number, you can make a computer program that can hop onto a phone network and do the same thing, in theory. You can also make fake claims as to what your number is if it requests it for Caller ID, so that helps with some of these things. America instituted the \"Do not Call\" list, which unfortunately is now a big public directory of names and numbers. There are laws that enforce this at hoime. People who are physically in another country? That's another matter entirely. We don't have jurisdiction to actually do anything about a lot of it. So all that said: robodialers are almost exactly what they say they are: computers/robots that dial phone numbers. They'll keep calling different numbers until a real person picks up, at which point it will connect to a real person. They will then run some scam or another, trying to steal money."
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brc25s | How does a network connect to other networks over WAN? | I mean in like how do we send a signal that could casted over to the other side of the world. Like do we send it to a satellite then send it back or do we send the signal on earth, I'm confused | Technology | explainlikeimfive | {
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"Intercontinental communications are typically done with undersea fiber optic cables. Satellites are used for this too, but have less bandwidth and reliability; So they're significantly less common, and mostly used for providing internet to remote locations that have no wired connections available. Undersea cables use extremely strong armor and shielding to protect themselves from the elements. They're typically buried slightly underneath the sand at the bottom of the ocean. They're planned in advanced to go through the most shallow points of the ocean.",
"almost all internet backbone traffic is transferred over copper wire or fiber optic cable. Since the days of telegraphy we have been able to lay cables across the ocean floor in order to transfer signals between continents. The distance to send a signal to satellite and back to earth again is almost always greater than the distance to send the signal over a cable, even if you're going halfway around the planet. Most communication satellites orbit at around 22,000 miles, so the round trip distance for a signal is 44,000 miles, while the circumference of the earth is only 24,000 miles.",
"Most of the long haul on an around the world trip will be on fiber optic cables buried underground and on the sea floor. If you have a command line available, type \"traceroute URL_0 \" or to some other destination (except on Windows, it's \"tracert\"), and you'll see a few hops to get to the destination. Each hop is a router that makes a decision on how to get to the destination. Those routers are computers, mostly expensive, specialized computers built just to make those decisions quickly, to keep track of how to reach everything on the Internet, and to do it quickly and reliably. Between each hop is fiber or copper cabling, or wireless links."
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brcuzm | How does a radio prioritize two identical frequencies from two different stations? | Driving into work today, with high dense cloud cover, my preferred radio station was cut in by another radio station of the same frequency. I recognize the cloud cover acted as a dish, and I typically get static through that particular stretch of road, but what makes my radio decide what frequency is dominant of the two? What would be the effect of being in an intersection of multiple stations? | Technology | explainlikeimfive | {
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"text": [
"Cloud cover won't have any impact of note. If it was an AM radio station then the ionosphere, active and reflecting radio waves, was the culprit. If it was an FM radio station most likely there was an unexpected transmitter problem, reducing its power for some period of time. In both cases the decision on which to play is the strength of the incoming signal."
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brcyf6 | Why do Adblock softwares not work on streaming platforms (Hulu, Fox, TNT, etc.) | Technology | explainlikeimfive | {
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"text": [
"the how: its a combination of adblock detecting scripts that then deny you the service, the ads built into the same content delivery system as the service - this makes it so you can't block the ads without blocking the service as well, and lastly unintentional coding errors that happen when you stop the ad from running. & #x200B; the why: hulu isn't free, its paid for by you watching ads or paying for ad-free. their intention is to feed you ads so they're not going to go out of their way to make their site work for people who block the ads.",
"Hulu, Fox, TNT etc have a huge incentive to find out how adblocks work and how to stop them. In comparison YouTube has a similarly huge incentive to stop adblocks, but to the adblocks themselves YouTube and adsense are the largest producers of the ads that their customers see. So adblockers specifically target YouTubes method of delivering ads, and all Hulu has to do to play ads is not play them like YouTube.",
"Because the ad blockers can't tell what's an ad and what's not. On most websites, the ads come from a separate ad-network. So when you load URL_1 , it'll have a little widget owned by URL_0 which will load an ad. Your adblocker sees the page attempt to load something from URL_0 and blocks it. But if the ad and the content come from the same source (included in the same video stream, for example), the adblocker can't tell what's an ad and what's content."
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bre3co | Why does using a chip credit card at the pump take so much less time than using one in the store? | Technology | explainlikeimfive | {
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"text": [
"Transactions at self serve pumps are often offline, so the card will say this person is good for certain amount of money. After you've filled up, the transaction is sent to your bank and taken from your account. Transactions in the store are often online, so a request is sent over the internet to your bank to check if you have available funds. Online transactions have to go through various networks and be processed by software so it takes longer. Source: I implemented a debit card system for a bank."
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brgbhy | How do power lines work? | Recently I saw a power line with 2 wires (hold on). Only one AC power line and one ground wire on top. If I understand power correctly you need at least 2 wires to make a circuit and power stuff. Also another question, which wires on the power line do what? | Technology | explainlikeimfive | {
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"text": [
"Three or 4 wires power lines are 3 phase transmission lines. There is also a thick line that runs under the 3 ones that carry low voltage data like telephone or cable tv."
],
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3
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bri5co | Why aren't foreign radio channels region-locked like their tv counterparts? | As we all know, legal live tv streaming services are usually blocked outside the national territory, with few exceptions. I'm guessing for copyright reasons and maybe public service fees in some cases. & #x200B; How come radio channels never get the same treatment? Surely they must be playing a lot of copyrighted music? I've never ever been blocked from listening to foreign radio. Why tv but not radio? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Just try to catch electromagnetic waves from crossing the border with a net. Technically with digital radio it could be possible, but overall it would be a huge, expensive hassle on both provider and consumer end (and likely easily bypassable anyway) just to block a 20-40km band along the border from listening to your radio."
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8
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brigfu | What makes the Video Player applications different? What is the difference between VLC, QuickTimePlayer and others | Technology | explainlikeimfive | {
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"text": [
"Different interface which gives you different looks/locations of buttons. Different tools (one may give you hotkeys to skip forward/back 1,5,10,30 seconds, slow down the speed, etc.) There are multiple formats for videos, one may not play all of them. Some are free, some aren't. Some have open source code (so you can edit it to your liking if you're savvy) some don't. Some have a more responsive development team and identify/patch bugs in a more timely manner.",
"Mainly two things seperate different video players: the way they look and interact with you (the user interface) aswell as which types of video can be played. The user interface of a video program allows for control of the program. Some programs like VLC offers the user more options and control so they can fulfill the needs of both advanced users aswell as those with simpler needs. It is more flexible but not all users need this flexibility. Another major difference lies in the ability to play different types of video. To play a video on your computer, your video player needs to understand the video. While some video files can be understood by just about any video player, some are made differently and needs a video player with special abilities. These video players have the ability to understand uncommon types of video and can play it for you just fine."
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brin65 | why do some electrical devices call themselves dust proof and what can dust do to non-dust proof devices? | Technology | explainlikeimfive | {
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"text": [
"Dust proof usually means sealed and enough volume inside the case to release heat. Dust in non dust proof devices can jam up fans causing them to overheat or jam up any moving parts."
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4
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brj4dy | How do all servers across the world ensure unique IP addresses? | I could be totally wrong here, but I’ve always been under the impression that IP addresses are unique in that for every address, there is one and only one server/computer, and viceversa. How do you accomplish this given all the different manufacturers, countries’ internet protocols, etc.? | Technology | explainlikeimfive | {
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"text": [
"Others have done a good job covering the basics, so I'll go into more of the technical details. The right to use Public IPs is assigned to companies and groups by organizations like ARIN (North America) and RIPE (Europe). Qualifying organizations (Large companies and ISPs) apply for and pay a fee to use IP address space and are assigned blocks of unique IP addresses that they are free to use as they see fit. This address space is advertised to the rest of the internet using BGP (Border Gateway Protocol) which tells the internet where those IPs are located and how to get there. If you attempt to advertise IP space that doesn't belong to you (effectively stealing IPs) your peering partners (who your WAN network is connected to) will soon recognize that and filter out (block) the advertisements effectively dropping your network off the face of the internet until you fix it. This can cause serious havoc to the internet and is taken very seriously. However the vast majority of organizations and private individuals are too small to warrant having blocks of IPs dedicated to them (the smallest issueable blocks are 256 IPs, while most companies only need 1 or 2). So instead it's more practical for most companies and persons to effectively lease IP addresses from larger organizations (ISPs). When you make a connection via an ISP they lease you a temporary unique IP address which is assigned to your modem. In the case of businesses (for an additional fee) a static or permanent unchanging address(es) can be assigned to the service. These addresses are unique and unchanging and therefore better suited for hosting websites and the like."
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brjp9q | what exactly is being “improved” when we see games graphically improving with time? | I understand that in a game world, we have different graphical features that come together to produce the visuals we see in a game, like lighting, textures, anti aliasing, etc. What I’m wondering is, when we see a company that comes out with the latest, visually mind blowing game in a series (lets take Uncharted as an example) what is involved in making the graphics nicer? What is setting, say Uncharted 4, apart from Uncharted 3? What’s happening under the hood that produces these improved graphics? Are the engineers at the company actually writing new equations or code to model reflections, water, shadows, and things differently? Is this just because hardware is becoming more powerful? Sorry if the question is vaguely worded, it is tricky for me to nail given I am not of a technical background myself. | Technology | explainlikeimfive | {
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"Generally speaking - increases in texture resolution, Instead of using a 100x100 pixel texture you use one thats 500x500 now your model is less blurry, has more detail - Increases in polygon count, more polygons allows more detailed features. go back to N64/PS1 and most characters didn't have distinct fingers due to keeping poly count lower. now you might have a few dozen polys just for a buckle on their uniform. - New lighting techniques, dynamic shadows, HDR bloom effects etc - New shaders and rendering techniques, from Depth of field to bump mapping, reflections etc. Sometimes it's new tech that's more effective at rendering more realistic effects other times it's old tech it just takes more processing power to run. with improvements on the same platform it might be the latter but there's optimization other places to make up for it.",
"Digital Foundry is a great source for details on graphics technologies for video games. They do a lot of comparisons between gaming hardware as well as between different installments of series over time. For example, see the one on [Farcry]( URL_0 ). The tldr is that the improvements are a combination of different techniques for modeling physics, geometry, and lightning, and enhancements to the machines gamers have access to. These factors take turns limiting what a game can look like with few exceptions. One consistent exception is the notorious Crysis, which was designed to take advantage of yet to be developed graphics hardware, and can still be made to bring modern hardware to its knees more than a decade after its initial release. Another trick that comes into play are ways to implement the same old techniques, but in ways that require less effort, freeing up precious resources on graphics hardware to do other work that can make games look even better. A recent example is a feature of new video cards called deep learning super sampling. This feature allows a game to be rendered at lower quality but **image enhanced** using an artificial intelligence trained on extremely high quality renders from the game...renders which no consumer video hardware could produce. By using this technique, a game could use the spare cycles to theoretically render more trees, or other terrain to present the illusion of a more complete world. Finally, the actual substance of games has improved as the promise of returns on investments have driven up the production costs of games. For example, a recent game, Grand Theft Auto 5 was one of the most expensive games produced but ended up making more money than any entertainment product (including TV shows, movies, ...) in it's first 24h...and it keeps making money years after release. Returns like this encourage higher production values for future games. This translates to better voice and motion acting, higher quality modeling of real life architecture, people, materials, and terrain, and better story writing. All of this is why games keep getting better and better. It's part better tech. It's part better hardware in gamers hands to allow past tech to be cranked up. It's part getting more efficient. And the last bit is the fact that games make a lot of money and can therefore justify huge production values."
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brkhqb | How do cameras capture nuclear tests so vividly without succumbing to damage from the blast? | Technology | explainlikeimfive | {
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"The camera sits in a bunker and is aimed at a periscope type setup with mirrors to film the test. [Special high speed cameras]( URL_0 ) use a fast moving mirror to capture incredibly high frame rate footage of the blasts.",
"This video, from Curious Droid, contains a lot of information on how we are able to record such tests from flying tanks shells, rocket launches to nuclear explosions. URL_0 Check it out, it is super interesting :)",
"Related question, what is the most recent footage that we can see of a nuclear explosion?",
"What is the X pattern behind some of the detonation photographs?",
"I was reading about one from Bikini island, where they were photographing the ignition point. They built a long tube that had a clear view of the ignition point, they built a series of super fast closing doors in the tube to protect the camera. If I can find the story, I will link it. I may have read it in this book. How To Photograph an Atomic Bomb [Peter Kuran]",
"Wouldn't the main damage to the camera be the very first pulse of radiation that isn't aborbed by the air? After that, the fireball is just a big glowing ball of superheated plasma (with heightened background radiation), similar to filming the sun. As long as the camera detector/film is kept well-shielded from that initial pulse of xays/EMP/etc, a millisecond later all should be fine. Edit: [example]( URL_0 )"
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brn8jh | What's the digital process of lowering the quality of a photo or video? Also is the opposite process a thing or just movie things? | Technology | explainlikeimfive | {
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"text": [
"Lossy compression. The opposite is largely just a movie thing. Only in the last few years has machine learning-based image interpolation become a practical thing, but it's just *interpolation*, basically an educated guess. It's reasonably good at sharpening some contours on upscaled images or guessing a generic replacement for a missing part of an image from the surroundings, but it's not some magic \"enhance\" that can bring back data lost in compression.",
"The opposite is called super resolution in computer vision. I've used it in an iris recognition system but there's a hard limit to how much information you can extract from a static neighbourhood of pixels in a single image. In the iris recognition system we take say 10 pictures rapidly, each offset from the last by a tenth of a Pixel, and use a fancy algorithm to combine it into a picture 10x the resolution. This let's us zoom in on your eye from a distance and identify who you are from 15-20m away. Scary!",
"Removing information from the file lowers quality, basically. Some things that can be done: switching millions of colors into thousands, blending similar pixels together, removing light beyond the visible spectrum of the eye (but that the camera still captured), compressing audio above or below the threshold of human hearing, etc. All of these tactics can vastly lower quality. Restoring information that isn't there anymore isn't really possible, unless it's saved in the file through a revision history. (See Obama's birth certificate - it was a joke people calm down.) You might be able to smooth out some details or blow things up with a magnifying glass or guess what color something was (black and white colorization does this for old movies, for example). Regardless, you can't read a license plate in a 240p video when the camera never captured it in the first place."
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bro6tx | Why can some video games host 10s of players with no lag while others can't seem to host a lag-free 1-on-1? | Technology | explainlikeimfive | {
"a_id": [
"eofaorr",
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"text": [
"Without even trying to explain what causes lag, the short answer is that some programmers know what they are doing and some don’t.",
"There are too many variables at play here. So I can't give a solid \"This is why\" answer. It can depend on what kind of game it is, what the server situation is like, and your internet connection. Some game companies host their own servers, which are usually well maintained and are on high quality connections. Others allow players to host their servers, which can have questionable quality. Some games are P2P (Peer-to-peer), in which your console/PC connects directly to the other players console/PC, this usually works well, but can lag if one of the players has a poor connection. In all instances, peek hours, when the most people are in-game, can usually result in lag due to high traffic."
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brornt | What causes glitch worlds/levels in video games? | The most famous example of this is the minus world, but I find most older games have this glitch. Where the hex byte(s) support warping to more levels that exist in the game, you can warp to glitchy levels. And there's also those games where if you are able to go out of bounds enough, you can be met with a scrambled mess of blocks and enemies. Example: URL_0 But why does all this happen? I know why you can access them, but what code in these games loads all of these glitchy levels and blocks rather than it going to a black screen? | Technology | explainlikeimfive | {
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"text": [
"The following is *technically incorrect* but *conceptually correct* - simplified for ELI5 purposes. Level data in, for example, a Mario game, looks like this: AAAAAAAA AAAAAAEA AABBAABB AACCAACC AACCAACC DDDDDDDD Where A = empty space, B = top of a pipe, C = vertical pipe, and D = brick ground. E = empty space with a Koopa in it. All 24 letters have some different tile and/or enemy associated with them. (In reality games don't use letters, but might use bytes with 256 values, or 2- or 4-byte pairings etc... but I'm simplifying things here) (Also, obviously most Mario levels are way bigger than 8x6 tiles, but I'm not typing out more than that!) When you enter a new level, the code says \"OK, go to the 38,794th line in the code and read 6 lines starting there to get the level data.\" But sometimes that \"38,794\" gets corrupted by some bug, and instead the program reads \"OK, go to the 12,804th line of code and read 6 lines starting there to get the level data.\" And what do we find at the 12,804th line of code? THE_PRIN CESS_IS_ IN_ANOTH ER_CASTL E.______ WELCOME_ Uh-oh, it's actual text, meant to get displayed in another place. But our level-building routine doesn't know that. It just sees letter-codes for various tiles. So it builds a level using those codes. T is a question block, H is the left side of a cloud, E is empty space with a Koopa... The end result is a nonsensical jumble when viewed as a level.",
"In some games, the 'glitch worlds' are just development worlds. Where the game developers can take the character to easily test certain functions of the game without having to manually get to each part in the normal game world. & #x200B; Some glitch worlds occur due to certain elements of the world being stored in locations where the developers do not expect the character to reach. Others occur because your characters X,Y coordinates, or some other numerical value, exceed the max numerical values and they either go negative, or reset to 0. This can cause older games to glitch out, as they do not run in VM's like modern games to. So the game may start accessing memory blocks it's not supposed to. This can introduce all sorts of weird behavior in the game, such as glitch worlds or the infamous 'Missing No.' in Pokemon."
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brpawd | What is hyper threading and the ZombieLoad vulnerability? | I know hyper threading is used for high workload processes but I have no clue what it is. Should I, an average computer user, be worried? I’m reading that installing the patch could slow my Mac down by up to 40%? | Technology | explainlikeimfive | {
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"text": [
"ZombieLoad is an attack that uses a vulnerability in the so called \"speculative execution\" of a different process running on the same core of the processor. Imagine that the processor running code is a car going down a street. Every once in a while, it comes to an intersection where it has to turn left or right. The car does not yet know this though - it has to look it up first, and until then it's just standing still. With speculative execution, the car will create a ghost car which will guess which direction is right. Once it finds out which direction is right a little bit later, it will either warp to the ghost car, or it'll delete the ghost and start over from the intersection, going in the right direction this time. Hyperthreading allows another car to drive in the same city. They can normally not see each other - but with ZombieLoad, they can see the ghosts. And by observing where these ghosts are going, malware can possibly find out what it's doing and extract sensitive data. > Should I, an average computer user, be worried? I’m reading that installing the patch could slow my Mac down by up to 40%? As far as I know, the vulnerability isn't as problematic for end-users as it is for companies using cloud services such as Microsoft Azure or Amazon Web Services to run their software, possibly with sensitive data. But I'm not a security expert, so I don't want to give you any recomendations about what to do in this case."
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brqi1n | Why do remote controls use infrared light instead of other wavelengths? | Technology | explainlikeimfive | {
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"Very low wavelength bands are already occupied by radios and microwaves and have a lot of noise. Visible light is visible of course. Ultraviolet is too energy intensive to generate, and you definitely don't want to be shooting x-rays around the living room. So the near-IR it is.",
"LEDs are the only practical light source for cheap, everyday remote controls. Red and particularly infrared LEDs were available long before other colours.",
"It is cheap to make and have the advantage that is it line of sight so without adding any complex pair system is it limited to the room and will not control stuff in different room or apartments or even houses that would be the case it you just transmitted for example radio wave. It had the drawback that it is line of sight so stuff like game consoles uses radio waves. But then you need to pair the device and the remote. That add user complexity and radio is a bit more expensive to use. You use IR and not visible light so you can't see the blinking like you can with many digital cameras.",
"IR sensors are cheap and easy to manufacturer and do not require approval from the FCC. Since you'll always be facing the TV, there's no need for an RF remote, as the IR sensor will always be facing you. Also, since IR is mostly limited to line of sight, it's highly unlikely that if your neighbor has the same make and model of TV, that their remote will be able to control your TV if they're very close. Where as with RF, this could be possible, which would make the system more complicated as special encoding methods would be necessary.",
"IR is cheap and energy-efficient. Also, the waves attenuate very quickly and can’t penetrate through material, which is actually very beneficial for TVs. If the waves could over-penetrate, you would have to worry about your neighbor changing your channel. Generally speaking, you’re only going to be using the remote in front of the actual TV, so LOS isn’t an issue. Not only that, but the lack of interference from other TVs makes it easier to program the remote itself, because you don’t need as many complex ID mechanisms to make sure the right remote is interacting with the right TV. You can use much more generic signals because of this, which makes everything cheaper and simpler."
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brr00x | How do scammers send you an email from your own account. | This has been happening for a little bit of time now. I receive an email from my own account and the message says I've been hacked. They also say they've made videos of me jerking off to weird porn and for a payment of several hundred in bitcoin they won't release the video. I just erase the emails because I know its crap, but how do they make it seem to originate from my own account? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Think of receiving an email like getting a letter in the mail. It’s fairly trivial and there’s often nothing enforcing someone from writing whatever name they want as the sender on the envelope. Letters have envelopes, and you can write whatever you want on them. Emails have “headers” that contain information like the sender name/email, the subject, etc, and you can forge information in the headers just the same. Edit: And to continue the envelope analogy, if I mailed you a letter but put your name/address as both the from and to addresses, there would be evidence that you didn’t send yourself the letter: the postmark would be from a different city or state. And the same thing with forged email headers - there is evidence in the headers that will clearly show you it was forged if you know what to look for."
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brr1re | how do radio signals (4G, WiFi etc.) manage to retain their information after passing through trees, buildings and other obstacles? And how are they not mixed up, intertwined? | Technology | explainlikeimfive | {
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"text": [
"They are, the key is there are error correction and detection algorithms that work to counter the problem. In bad environments they don't always work. Also, many newer devices actually utilize the attenuation and reflections to improve signal quality. Take a look into [MIMO]( URL_1 ) technology. They do what is called [beamforming]( URL_0 ) where they vary the signal being output on multiple antennae to create hot spots in the signal at the receiving antenna(e) to improve reception. When multiple devices are connected it will actually change the beam forming per device moment to moment depending on the destination. It's really cool stuff. Edits: Links, typos. Edit 2: Figured I could expand as well. When you're dealing with reflections or other signals that could potentially interfere, they are usually a bit weaker than the main signal. This means that a receiver can filter them out by simply ignoring signals that are weaker than a certain level. This is called the noise floor of the radio. Think of it like being in a room full of people talking and ignoring all the background conversations because they're harder to hear and focusing on your current one. Attenuation of the main signal works similarly. As long as the signal isn't attenuated below the noise floor, it will work. If the operating environment for the radios is bad enough, it may be impossible to get a strong enough signal to overcome the noise floor, and then nothing works.",
"First the not intertwined bit: Different types of radio signals are allocated to certain bands. Some bands are a free for all (like 2.4 GHz for cordless phones, bluetooth and early wifi routers), others are strictly regimented. In the states this is by the FCC. You (as a device manufacturer or a broadcaster) send waves out in a frequency band you aren't supposed to you get slapped big. Fines or even revoke your device licence. Each band of frequency is allocated for specific purposes (this band is UHF old school TV, this band is FM radio channels 97-108), another band is radar, another air traffic control, another is CDMA old school cell, another is 4G EDGE GSM whatever cell traffic. Other countries have same or similar, and have their own FCC and \"spectrum\" allocation which may or may not be similar. So within each band, it may be further broken into channels. Most cell, radio, ATC communication is like this. AM/FM and broadcast TV too. Groups like the FCC make sure that one station on a channel doesn't clobber or cross talk with another by ensuring geographical separation. Two cities may both have a 107.9 FM station, but they won't be geographically near one another... or it is ensured that on most days the broadcast transmitter of one doesn't reach the broadcast area of another. For communication channels, more traffic gets stacked into a single channel using digital multiplexing. There's various ways to do this but its akin to letting phone 1 talk during timeslot 1, phone 2 during timeslot 2 and so on (thats time division multiplexing). Next passing through stuff: Different frequency signals travel through different things to different degrees. Low frequency waves generally travel very far thru stuff, high frequency waves travel shorter distances or are \"attenuated\" more by various mediums. Whales use low frequencies and can hear each other over hundreds of miles. The loudest chipmunk in the world will only be heard a few hundred yards. AM signals are lower than FM signals, thus can be heard hundreds of miles away, only a few dozen miles for FM; given the same height of tower and strength of transmitter (and atmospheric conditions etc. etc.). Now add in error correction etc. - analogue signals travelling through walls, trees etc., well not much you can do to correct that - you get static. Digital signals however, you can use error correction. For broadcast signals, again, you can't ask for the last second to be rebroadcast, but perhaps there is some extra redundant data being sent and you can reconstruct part of the msg that is missing. Or, in the case if digital wifi or cell signals, if you didn't get a msg correctly you can ask for it again. Also don't discount that a lot of these signals can travel through windows and bounce down hallways and around corners. [Here's a map someone did that shows how wifi signals get weaker as you move further away from the router in an apartment.]( URL_0 ) Note that some signal is getting around corners but further and the more corners, less straight line you are the weaker the signal. In wider area networks, this is where devices called repeaters come in. All they do is take the wifi or wireless signal and \"repeat\" it. Like all those relay fires in LoTR, signalling Gondor for aid. Emergency radio networks and public internet and cell networks all use repeaters to deep inside things like tunnels, the subway, really large buildings etc. A bit more on traffic congestion in certain frequency bands: there are some frequency bands where traffic is largely unregulated. The 2.4GHz band is one. Anyone who wants to broadcast there, go right ahead. No FCC van will pull up and give you a fine (within limits). So thats why in this band we have: cordless phones, baby monitors, early wifi routers, bluetooth runs here (I think)... and really cheap microwaves. My wifi would go down everytime I microwaved something. There are \"channels\" that you can change your device to, like your wifi things... if your wifi traffic sucks, try changing your router away from \"auto\" to use a particular wifi channel (0-11), see if it helps."
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brr4ue | How come a foot or two of brick/plaster can stop a cell phone signal but (moderate) hills and densely packed buildings in urban areas do not? | Technology | explainlikeimfive | {
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"Hills and buildings in urban areas do block cell phone signals. A Lot. In cities cell companies put relays on the tops of buildings to spread coverage from the main towers and prevent dead zones. In areas with hills they will but relays or towers on said hills. But in both cases you will have bad coverage in some parts of a city, and you will have hills making dead zones in rural areas.",
"A phone signal (or any EM radiation) is fundamentally the same idea as a flickering light. A light will shine through some materials, and bounce/reflect off and around objects in an otherwise open space. Your phone signal acts similarly."
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bruyez | Why the "black color" in TV screen are not black? | It so disappointing when you watch movie in the dark and you can see that the black color of your TV it's not the same black as the room that you are in, it's looks more like a dark grey. | Technology | explainlikeimfive | {
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"eogpmkv",
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"text": [
"It's because instead of the tv turning off pixels to show black, they are just showing the minimum possible light. You should look into oled panels. They are pricey but should give you what you're looking for",
"One way to create television displays which is very common these days is an LCD, or liquid crystal display. There is a white light behind a series of tiny colored cells (red, green, and blue) which are blocked in varying amounts by a liquid crystal matrix in order to form the desired image. The problem is that the liquid crystals can't ever block *all* the light perfectly so they can't reach a perfect black. The backlight always makes it through a little bit. An older technology of a CRT which uses an electron beam to make the screen glow doesn't have this problem but they are bulky, heavy, and use a good bit of power. Newer technology of OLED displays don't have this problem but they are expensive and subject to wear that can \"burn in\" frequently displayed images. So it is all a trade off."
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bryegg | Why do phones and tablets power on and off with full 100 % brightness regardless of the scree brightness settings? | Technology | explainlikeimfive | {
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"text": [
"There needs to be a program running to control the screen brightness for it to be set to some amount. In those situations, there is no process running for that, as it requires an operating system to run, which isn't running completely at that time. There are ways around it but its not really a necessity for the few seconds it takes for the phone to turn on or off."
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5
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bryftk | What is the difference between a library and a framework? | Technology | explainlikeimfive | {
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"text": [
"A framework is a basic working model of a solution to some problem. For example, when you go out to eat, the basic framework for a meal is: drinks, appetizers, main course, and dessert. Now, you can modify this all you want. Maybe you want dessert wines at the end, or maybe you want to throw in a salad course. The point being is that a framework gives you a starting point from where you can jump from. A library is a working set of tools to solve a specific problem. To keep the restaurant analogy going, when you go to a restaurant, it is likely that they do not physically make their own silverware, instead they go to the store and buy it as a restaurant’s job is to focus on the food, not the utensils. In this case, the library would be utensils as the specific problem they solve is aiding in eating food. At the end of the day, libraries aren’t needed (e.g the restaurant can make their own utensils if they really wanted), but they greatly help increase efficiency. Generally, you use frameworks and libraries together. Say you were to open a restaurant, the basic meal framework would be as outlined above and you would use “libraries” of furniture, silverware, etc to aid in the operations of the restaurant. You could even consider the chef to be a library as he/she solves the problem of making the food if the owner themself isn’t cooking."
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bs0jjw | confusion on ssl certificates | I feel like I have a very flawed understanding on how ssl certificates work here so thought I would explain how I see it here so anyone can correct me. As far as I understand, Bob has a certificate issued by the certificate authority and encrypted with his private key to prove to Alice that she is indeed receiving a message from Bob. However, what is to stop Eve from getting Bob’s encrypted certificate and then when Alive wishes to talk to Bob (although Eve is playing man in the middle - so Is actually talking to Eve) she gets back a certificate that looks like it is from Bob (but actually from Eve) and as far as Alice is aware, is talking to Bob upon decrypting with the certificate public key Am I missing something here? Or is my understanding of it totally wrong - thanks to any replies | Technology | explainlikeimfive | {
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"Slightly simplified, it works like this: An SSL certificate contains a public key and is signed with the CA’s private key. So it looks like: > Bob’s public key is ABCD. < CA signature > Bob sends that to Alice when she connects. Alice has the CA’s public key on her computer, so she can verify the signature when she gets it. Then, Alice generates a random encryption key, encrypts that key with Bob’s public key, and sends it back. Bob decrypts it using his private key and the rest of the conversation is encrypted using that key. Eve can pretend to be Bob and send his certificate to Alice instead, that works fine. However, when Alice sends back the key to be used for the rest of the conversation, Eve can’t decrypt it, so she can’t establish a working connection to Alice.",
"Bob has a public key for his mail adress bob[a]bobinc.xd - he's giving that one out to everyone, to Alice, to Eve, whoever wants it, gets it. When Bob sends a message from bob[a]bobinc.xd, it's using his private key. Only Bob has this one. He didn't give it to anyone. When he sends his message to Alice, her email program looks if it has a public key for bob[a]bobinc.xd. If she does, she can read Bob's message and gets the info that the keys fit. If she doesn't, the mail gets rejected. Since only Bob has his private key, Alice can't pretend to be Bob."
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bs3on8 | What are the main issues with Nuclear Power and why do the majority of people have a problem with it? | Technology | explainlikeimfive | {
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"By far the biggest concern is nuclear waste. There are varying types of nuclear power, and some produce waste that is less dangerous than others, but all produce at least some dangerous waste, and that waste continues to be dangerous for thousands or even millions of years. But realistically, the waste produced find nuclear power plants is far easier to deal with than the waste produced by burning fossil fuels, if for no other reason than there is far less of it and is much easier to contain. So the fears about nuclear power are largely overblown.",
"It's barely a majority who oppose it; polling has consistently shown that a majority of Americans support nuclear power, with only one 2016 poll showing a majority opposition. The drop is almost certainly due to the Fukushima accident - an incredible piece of bad press for nuclear power. Nuclear power is generally safe, but the consequences of an accident are far, far greater (particularly in perception) than other power sources, and the risk is non-zero. Many people who do support the use of nuclear power are opposed to having it in their area; this stance is known as NIMBY (Not In My Back Yard), and is a direct consequence of the perceived safety hazards of nuclear power. Another top concern regarding nuclear power is the risk of terrorist activity. There have been successful attacks and security penetrations at nuclear plants worldwide, including in the United States, and the current climate of fear around terrorism makes this a top concern. Nuclear power also has to compete with wind and solar, both of which have very strong press, government support, and \"curb appeal\" (anyone can put solar panels on their house, it's waste-free, requires no special resources to operate, etc). From an economic point of view, nuclear is far from being the best option when it comes to green energy; throw in the bad press and risks, and it's a low-tier option."
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bs4d3j | Whatsapp video calls | ELI5 So when me and my friend video call each other then when we play music through our phone speakers then we can still hear each others voices but not the music | Technology | explainlikeimfive | {
"a_id": [
"eoisxlv"
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"text": [
"Most phones and devices that can carry sound have what is called \"echo cancellation\". Oversimplified the phone knows what sounds are being played trough the speaker, and can then try to ignore those sounds when the microphone picks them up. Audio is just waves, and you can cancel one wave with it's inverse wave. Phones will play the inverse sound in to the microphone when the speaker plays it, so that the \"bad\" sound cancels out while all other sounds is undisturbed."
],
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bs6jdj | How does Coast Guard monitor multiple radio channels? | We sometimes use a marine radio, and I know that the coast guard is monitoring channel 12, 16, 68, and 72 at minimum. How do they do it? Are there four employees for the four channels? One employee with four ears? A special device that listens to all four and transfers between them? Couldn’t find anything on a google search | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"**Back in my day** we only monitored 16 and maybe 22a. Multiple antennas up and down the coast all to connect to one Coast 'Group' where **a single radioman would monitor** all the static waiting for a call. Some consoles had a light which would indicate which antenna was getting the signal. If we missed it, we would broadcast across all antennas until we figured out where you were at. The radios were fast scanning multiple frequencies off each site. We also monitored 121.5mhz (civilian air distress) and 243mhz (military air distress). CG Cutters also monitor various frequencies on the bridge. Small boat stations may also monitor distress frequencies with local antenna but usually turn the watch over to the Group at night. There used to be larger communications stations that would monitor entire swaths of the world but those only monitored HF and MF. Antennas would be set up all over the place and end up in places like Hawaii, California, Kodiak, Guam, Miami... etc... & #x200B; *^((edited for clarity)**)*"
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bsaoex | Why do guitar amplifiers give off bad feedback? guitars in giant rock concerts don't normally do this, how they can be so loud without feedback? | Technology | explainlikeimfive | {
"a_id": [
"eoktuht"
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"text": [
"The guitar amps/setup at rock concerts are different to your typical bedroom 30watt fender amp. Firstly, at most large concerts, amps are ethier mic'd up on stage, or off stage in an Isolation Cabinet. The musicians will probably have 'in ear monitors' (head phones essentially) for listening to all the audio they need to hear. This essentially means that its much harder for a feedback loop to occur as any amp noise isn't being directed to the guitar. Secondly, a lot of feedback is caused by noise, a few things can remedy this. 1) A noise suppressor - This acts as a gate where low-level noise such as power-hum isn't let through to the amp, as soon as anything louder is detected (for example playing the guitar) the gate is opened and sound is let through to the amp. This makes feedback harder to occur (in simple circumstances) 2) Power conditioners - These help prevent 'noise'. Which i think is commonly referred to as 'ground hum' ? Any large concert will have (high end) noise gates and power conditioners to help prevent unwanted noise/feedback. Note : A lot of musicians will have their 'rig' off stage, however they'll have an amp or speaker on-stage so they can intentionally trigger feedback by walking up to said amp/speaker and dry-humping it with the guitar. This is a very intentional setup which prevents feedback in 99% of the regular performance."
],
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8
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bsg3gb | How does the file compression work? | Technology | explainlikeimfive | {
"a_id": [
"eon14tx"
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"text": [
"* Compressor looks for larger patterns of data inside the file that also repeat a lot. * Compressor makes a list of those patterns. * Compressor searches through the file and replaces each instance of that pattern with a reference to the list. * De-compressor takes the list and searches through the file for references, and replaces them with the full pattern from the list. So even though you are adding a list to the file, because you are replacing the patterns with much smaller references, you end up saving space. & #x200B; Example: Original - \"I once ate dinner with Albert Einstein. Not the real Albert Einstein, but rather a ghost-like version of Albert Einstein. And when I say dinner, I don't be mean me and Albert Einstein's ghost went to a real restaurant, I mean I was dreaming about going to dinner with Albert Einsein's ghost.\" & #x200B; 293 characters & #x200B; Compressed - @ = Albert Einstein \"I once ate dinner with @. Not the real @, but rather a ghost-like version of @. And when I say dinner, I don't be mean me and @'s ghost went to a real restaurant, I mean I was dreaming about going to dinner with @'s ghost.\" & #x200B; 244 characters & #x200B; You can see, even with adding the list of patterns, we still save space compared to the original."
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bshm20 | How have Olympic gymnasts improved so much from back in the day. | I was watching old gymnast clips on YouTube and the routines look extremely simple compared to the level of acrobatics that go on in modern day gymnastics. Why does it seem like now gymnasts are able to do incredible feats that people didn't do before. Thanks | Technology | explainlikeimfive | {
"a_id": [
"eonb8a8"
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"text": [
"Back then people still needed jobs, now they dont and can practice harder for longer. And science helps by showing then methods on improving motions. You cam find cool videos on youtube"
],
"score": [
7
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bsjxlo | How does a Lava Lamp work? | Technology | explainlikeimfive | {
"a_id": [
"eons69r"
],
"text": [
"The “lava” heats up and expands slightly decreasing its density. Which it is already close to the rest of the liquids density. When it becomes lower than the other liquid it starts to float which moves it further from the heat source and then becomes more sense and causing it to fall back down."
],
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bskgk6 | Help me understand why we can't see stars in pictures taken from space. | Technology | explainlikeimfive | {
"a_id": [
"eonwgc8"
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"text": [
"You can see lots of stars in pictures taken from space, that's all the Hubble Space Telescope does. You can see stars in pictures taken from the ISS, as long as the Earth isn't in the picture ([my favorite]( URL_0 )). The Earth is really bright, particularly during the day. Cameras, and eyes for that matter, can't image a really bright thing and a really dim thing at the same exposure. That's why when you look up during the day, you don't see stars. The stars are there, but the sky glow (the blue scattering) is brighter than the stars."
],
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"text_urls": [
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"https://www.nasa.gov/content/milky-way-viewed-from-the-international-space-station"
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bskym4 | with content being created on a daily basis and posted to social media or any other outlet, how is it all stored and managed? Will we ever run out of ‘space’? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"TLDR: Yes, but then they'll just add more. Speaking as a Storage Administrator working in the IT industry, if you give users space they will find a way to fill it. The data stored by web-based apps of this scale are typically in the form of databases and file stores located on dedicated storage appliances rather than individual servers. Think of this as a server rack full of hard drives controlled by a device that allows multiple servers to talk to it simultaneously. We call this a SAN (Storage Area Network) These devices have massive amounts of space, often have built-in compression and de-duplication (replacing multiple copies of the same file with a single instance of that file) and are able to be expanded dynamically. They also include different Tiers of storage, files that are accessed frequently are stored on fast but expensive SSDs (Solid State Drives) and less used archived data is storage on slower but significantly cheaper spinning disk hard drives. Basically you can buy another tray full of hard drives and click it in as you need it.",
"All content on the internet is stored on computers not unlike the one you have at home, but with a lot more hard disk space and usually more processing power as well. These are your web servers. Companies maintain huge rooms full of servers and sell access to that storage to other companies. Since engineers are coming up with more efficient storage all the time, you can have a huge amount of data storage in a very small physical space. It is ridiculously cheap to store data nowadays. So no, the chance of running out of space is relatively low. A bigger concern is the durability of the data. Hard drives can degrade over time and are susceptible to data loss from physical disturbances (say, an earthquake or simply dropping it). That means a good data center is built with redundancy in mind, maintaining multiple copies of the data and even copying it to analog storage medium like tape. Edit: Software also keeps getting better at storing more information with less \"data units\", i.e. bytes thanks to clever compression algorithms. So the space you need to store a high-resolution image today is a lot less than what you would have needed 10 years ago."
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bsnagp | How did physicists figure out the structure of an atom at a time when it was impossible to observe them? | Especially, the 3 main parts of the atom - electron, proton and neutron and the fact that electron whirled around the nucleus and that the nucleus had proton and neutrons, etc. It's a complex structure and I am struggling to understand how they were able to hypothesize it. | Technology | explainlikeimfive | {
"a_id": [
"eooiigt",
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"text": [
"The first experiment was done by Geiger, Marsden, and Rutherford. Basically, they shot alpha particles (a helium nucleus, so 2 protons/2neutrons bound together) at pieces of very thin gold foil. The idea is that charged particles like the alpha particle should get deflected based on the electric force with other charged particles. The particles get deflected in a way that suggested a positive core, and a cloud of electrons. Basically, most of them did nothing, which tells you they \"missed\", but when they did deflect, it was for a pretty large value. At the time, the dominant theory was actually a smeared mush, the 'plum pudding' model. Neutrons came later- they were harder since they don't have a charge. But we knew something was up, because the protons didn't immediately repel each other. At first, people thought there must be electrons in the nucleus to handle things, but it didn't match up with data. It was discovered by Chadwick in 1932, where radiation experiments he did had nuclei that ejected neutrons (which are chargeless, but still have mass etc, so they're detectable). > when it was impossible to observe them? In most cases, we don't observe them like you would normally think of them. We use similar techniques to the Rutherford experiment, just a lot more refined, and then reconstruct an image from it. A lot of small scale physics works roughly on this idea. If you want to study something tiny, you find something roughly the same size and hit them against each other. Then try to back your way out of a reasonable model",
"Well, it was an iterative process. There was no one experiment or theory that definitively showed how atoms are; it was a number of iterative discoveries and false starts made over many years. A brief window of this process: when electrons were discovered, it was theorized that atoms consisted of electrons in a cloud of positive charge. However, an experiment consisting of bombarding thin gold foil with positively charged particles revealed that this wasn't the case. If the previous \"plum pudding\" model were accurate, the particles would be slightly deflected as they passed through the foil. But instead, the particles were observed to sometimes pass through the foil with almost no deflection at all, while some bounced right off. This indicated that instead of a cloud of positive charge, there was a tiny nugget of strong positive charge; the nucleus."
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bsndny | How do they turn black and white shows into color? | Technology | explainlikeimfive | {
"a_id": [
"eopnf0n"
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"text": [
"1. Take a colourfully vibrant picture. 2. Turn it to grayscale 3. note which colour turns to which shade of grey 4. apply it in reverse to an originally grayscale picture 5. profit"
],
"score": [
3
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bsoi7m | The difference between old landline phone calls, cellphone calls, VoIP and calls made through social media sites | Technology | explainlikeimfive | {
"a_id": [
"eop154o"
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"text": [
"I'll give it a shot. Back in the day old landline calls came to your house over dedicated copper wires. These even ran a little bit of current which would ring the phone, which was why hard phones like that could work without electricity - they had a little bit of electricity to them already. Old phones had microphones and speakers which worked with electromagnets to produce analog signals that came over the copper wire. Cellphones are essentially two way radios that work from local cellular towers. Network speeds like 2G, 3G etc. refer to the frequencies that are used to transmit the signals through the air. Your cell phone connects to a nearby cell tower, and as you move around your signal gets handed off from tower to tower (which explains why calls get dropped.) VOIP are straight up digital calls over the internet. Your voice gets converted into digital packets and routed over the internet. You can use a VOIP \"box\" like Vonage which may plug a regular phone into it for at home use. Or you can even use a VOIP app on your phone. This app would place calls using a WiFi network on your phone, or if you were out and about, it could even use your phone's data network. In this case, though, the VOIP app on your phone would encode the audio into digital data before sending it onwards. I'm not sure what social media sites you're referring to, but most likely those are also simply VOIP calls just with a dedicated client."
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bspy8m | Why do larger capacity SSDs have better read and write speeds than smaller ones? | Technology | explainlikeimfive | {
"a_id": [
"eop7fli"
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"text": [
"Higher capacity SSDs are very similiar to lower capacity SSDs (for the same model), but have more flash chips to store data. The controllers in SSDs can access these chips in parallel, at the same time, and so can transfer more *total* data to more chips in the same amount of time, than they could with any chip individually."
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bss5dn | Why has split screen gaming disappeared? | Supply and demand seems to have failed here. History has shown a huge market for split screen gaming (Halo, early CoD, years and years of N64 including Goldeneye, etc). Split screen gaming is amazing for young siblings, sleepovers, and college dorm rooms. Why the lack of supply? | Technology | explainlikeimfive | {
"a_id": [
"eoppvb2",
"eoptd7f",
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"text": [
"Because Internet. You can just play games online and be able to see the whole screen. Many times you don't need to be huddled around a game console with your buddies playing split screen.",
"Split screen is just too intensive on the systems. To do a proper split screen the system essentially has to render 2-4 separate players. That takes a lot of system resources and with the new graphically intensive games coming out, that becomes increasingly harder to do. Consoles are also restrictive in how much resource can be included because to actually sell they have to stay in an ideal size parameter and cost worthy to the average user while still turning a profit for the developers. Studies have proven that more then $500 for a new release console will discourage many people from buying them as well as being to bulky and hard to move. Ps3 had a really rough launch because it violated both of those parameters and they tried to climb to $600 new release for a really big heavy system that recieved huge back lash and killed the sales of the system. There is definitely some financial motivation as well to the daying days of split screen but it's more technology sound that it's just not feasible to pack that much power into something and still come out cost worthy.",
"One of the issues that hasn't been mentioned is that FFA deathmatch and small game modes like 2v2 have also fallen out of favor. By far the most popular games are team based shooters or wide open battle royale games where 4 players are far less fun."
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bst0hd | How touch technology works? | Technology | explainlikeimfive | {
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"Conductivity. There's an electric field across the whole screen. Your fingers are conductive, so when you touch the screen, some of that electricity drains away. The device has sensors all around and so can tell how far across and how far up that screen that happened. That tells the computer exactly where the touch happened.",
"Also, there's resistive sensors. They have something like two webs of conductors separated by an isolator. When you press on their surface, you short-circuit small wires inside that sensor and the device will detect current and, based on which wires the current is, will determine where you pressed it. Unlike conductive sensors, resistive sensor can work even when you're wearing gloves or underwater or in dirty environment. But they interfere with display quality (they are slightly opaque), they are somewhat unreliable and not as precise as conductive sensors."
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bswxfi | OS (C:) vs DATA (D:) | Hi everyone. What is the difference between the OS (C:) vs DATA (D:) drives on a laptop. Are they for different things? Can D not be used for games and things like C? Why is D so much larger? | Technology | explainlikeimfive | {
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"It's just two separate drives. The separation can be physical (i.e. The drives are two physically separate drives) or it can be logical (there's only one actual physical drive, split into two partitions). If the separation is logical, then it's entirely up to whoever installed the machine. It's common to make a smaller partition for the operating systems and some of the installed software, and a larger partition for all the data - documents, pictures, videos and such. That way you can easily delete the entire system partition without touching the data partition (for example if you want to reinstall your operating system from scratch) However this separation isn't required - it's also possible to have just one drive with just one partition which holds everything, both the programs and the data. Nowadays computers often come with two drives - an SSD (solid state drive) and an HDD (hard disk drive). SSDs are faster but smaller and more expensive than HDDs, so you usually have a small SSD for the operating system and programs (which benefit from fast access to the drive) and a large HDD for the data (which doesn't need to be as fast).",
"In the old days, computer manufacturers didn't have a way to easily name drives the nice descriptive names that they do now, so they used letters. * Typically \"A\" was for floppies. * Then \"B\" was for a second floppy, or backups. * When hard drives became common, \"C\" became common for hard drives. * When CDs became common, \"D\" was used for the type of drive that could read CDs. Et cetera, et cetera. By default, Windows will just use the next available letter after \"C\" for any new drive it sees, but nowadays, you can assign other drive letters if you don't want to use the defaults.",
"It is just tradition. If your computer has a C: and a D: drive you usually use a small fast drive for the OS as C: and a larger slower one for the data. Even if you just have one physical drive, it might make sense to partition it up into a drive for the OS and one for data so that the data drive ending up full due for some reason doesn't stop the OS from working."
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bswz2p | Image sizes. If the camera settings stays the same and the image is stored as a set of pixel values, why does the image size change? | On my smartphone, the largest image is around 8mb and the smallest in the same camera settings is around 2mb (images of different objects though). Why is there such a huge difference in image size? | Technology | explainlikeimfive | {
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"The images are likely being compressed. Say for example you take a picture of someone in front of a flat white wall. Uncompressed the photo file would have to explicitly store that every single individual pixel of the wall is white, while a compressed file would store “all the pixels between *here* and *here* is white. Uncompressed: 1, white 2, white 3, white 4, white... Compressed 1 - 4, white. Photos of highly varied and colorful scenes can’t be compressed as much and therefore the file is larger."
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bsy8z0 | How do the saws used to remove casts not break skin? | Technology | explainlikeimfive | {
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"It doesn’t actually rotate, it just vibrates back and forth, it ‘cuts’ through the cast because its hard and sturdy, when it hits your skin it does no damage as your skin actually moves with it due to its flexibility.",
"Chances are that it was actually an oscillating saw even if it had a round blade. Those just swing back and forth a little bit. That makes them good at cutting hard things and bad at cutting soft things.",
"When I was a PA student in my clinical rotations, I was tasked with removing a cast from a child with said cast roving saw. He was terrified so I said \"look, it doesn't hurt me\" and touched it to my palm. Yup, sliced right through like butter. Sadly, I wasn't allowed to practice my suturing skills on myself... Or remove casts. Poor kid'l never be the same.",
"The saw blade moves back and forward very quickly and only cuts an object that has some solidness to it. The cast being rigid can be cut but human skin moves with the teeth so can't be. Source: medical engineer and had the exact same thought about a month ago. Tested it out, while it doesn't cut you prolonged pressure does give you a nasty friction burn",
"The tool used is called \"oscillating saw\", or as popular in actual trade tools, a \"multitool\". It vibrates back and forth, thus being able to saw through rigid materials, but not really able to di anything to flexible and malleable skin. They are also known to be nearly useless for anything but plaster in the trades, so...",
"Oh, one I know! It uses vibration instead of a chain. The cast can’t vibrate so it breaks. Skin can, so if it hits skin it just feels vibration."
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bsz3qp | How do random glitches happen on computers and smart phones when the code is perfectly fine? | Technology | explainlikeimfive | {
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"They happen because the code is never perfectly fine. There are errors in any software. The code just mostly works, while in a stable situation. Once in a while something unexpected happens - like a network loss, or a hardware problem, or some weird user input - and the software might not be ready for this kind of scenario. This is when you see a glitch.",
"Imagine building a bridge. Now imagine building another bridge on top of that one. Now imagine ANOTHER bridge on top. Repeat ad nauseam. Your foundations become more unstable the more you pile on. Think of the game of Jenga as a good real world example. Even if every one of those bridges worked “perfectly fine” they were not designed with other bridges in mind. The more bridges you have to deal with, the higher the chance that parts no longer work together. Even if some of those bridges were designed with other in mind, they weren’t designed for ALL other bridges. Then there is the issue of timing. Even if there’s only one bridge, delays can cause errors that in a normal situation would never happen. If one piece of software requires the information from another piece of software, then an exception can occur if they don’t get that information fast enough. An extension of this is when you have two pieces of software both waiting on each other, resulting in a never ending loop of waiting until the system runs out of memory and crashes."
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bszz8y | how can we hear people’s voices through a phone? How can our voices travel across the world through a mobile? | Technology | explainlikeimfive | {
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"Voices are sound waves. A sound wave is a change in air pressure, and you can describe all the information in a sound wave by describing the change in pressure over time. To make voices into electricity in your phone, you put a diaphragm near an electromagnet. When you talk, the air pressure makes the diaphragm move, and that makes electricity in the electromagnet. Now, instead of a change in pressure over time, we are dealing with a change in voltage over time. If you hook the electromagnet up to wires, and hook those wires up to a computer, you can convert the changing voltage into a series of numbers. This is a better way of recording sound, because once you have numbers, you can design error-correction techniques to ensure you don't lose any data. If you have trouble connecting one computer to another, you can store the numbers and resend them later, etc. Putting it in numbers gives you flexibility. Now that you have the voice recorded in numbers, you need to convert it again: this time, into a radio wave. This is also voltage over time, but instead of electrons in a wire, it is electromagnetic waves through space. Those waves go from your phone to a cell tower and are converted back into numbers. Then they may be converted into waves again, or put back over a wire. Either way, the numbers are broken up into groups called packets and put back together once they get to their destination. This is so each packet can choose the best route to the destination, instead of the whole message having to follow the same route. This makes things faster. At the destination, the whole process runs in reverse: radio waves or voltage on a wire back into numbers again. Then numbers back into radio waves from another cell tower, which are picked up by the other person's phone, and turned back into voltage on a wire. The voltage on a wire is hooked up to a diaphragm next to an electromagnet - it looks a lot like the microphone you spoke into, but is designed a little differently. This time, the electromagnet moves the diaphragm, and the diaphragm pushes on the air to replicate the sound of your voice."
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bt22wo | When you load a new website how can we trust the website is legitmate? Is the ssl certificate downloaded in browser or perhaps we verify signed certficate with the CA immediately? | Technology | explainlikeimfive | {
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"the SSL certificate is sent by the webserver to you, which is valid only for each connection you make to the webserver (as it is part of the encryption). You (or your browser) check the legitimacy of that certificate by checking that some trusting agent has signed that certificate. An attacker could have sent his own (false) SSL certificate, but then it won't be signed by some trusting agent. Unless the attacker has also compromised the trusting agent, in which case your browser (and everyone else in the world) should ignore the signatures from that agency."
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bt2d5s | During commercial breaks, why do they sometimes play half a second of one commercial before switching to another? | Technology | explainlikeimfive | {
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"Saw this from a guy who scheduled TV commercials Every hour of television, there are two local breaks, one minute each. If your local cable company sells that time, a local ad will run. If your local cable company does not sell that time, it defaults to whatever the network chose, usually a specific type of ad called \"Direct Response.\" Sometimes the Networks center and the Cable Company's center are not in synch. Watch FX, it's off by about 5 seconds. Most networks it's no more than 1 second."
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bt3h3t | How people move bionic limbs with their thoughts like normal limbs? | Technology | explainlikeimfive | {
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"The advanced prosthetics that work this way are very rare. They use electrodes connected to the nerves that used to control muscles. When they detect electrical signals in the nerves, they move the arm. The user \"learns\" to control the limb just like how a baby learns to control their limbs. You make random signals and the arm responds randomly. The brain is very good at learning in this sort of situation, where there is visual feedback. It's not as good as when there is sense of self, but it's pretty good.",
"They don’t, not yet anyway. Currently most powered artificial limbs have electrodes or other switches that sit on still present muscles. When that muscle is moved, it corresponds to a movement in the prosthetic."
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bt4iwy | How are game replay files so small? | To give a concrete example, I play this game called world of tanks blitz. They have a replay system where the replay file itself is < 1MB and can be imported into the game client to view the entire game footage. So my question is how do these replay files store the entire state of a complex game like this with many factors in < 1mb? | Technology | explainlikeimfive | {
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"It's because it's not rendered into a 3d video file. It's just instructions for the system to re-simulate the player movements in the preloaded 'map'. Hope that makes sense",
"Not exactly sure how world of tanks works but all the file has to contain is what object is where facing what at what time. Say the game runs at a rate of 60 refreshes per second, in 3 dimensions, another 2 dimensions per object for which way it faces assuming facing is always up, + number for model type. Say each number is 4 bytes, game length is 5 minutes, that is 4 bytes * ( 3 dimensions + 2 directions + 1 player number) * 60 refreshes per second * 60 seconds per minute * 5 minutes * 10 players is approximately 4 million bytes, or 4 megabytes. Toss on some compression and me probably being wrong in places, that number can be taken down a little more. The key thing is that it doesn't have to store a video from all perspectives or anything, or any of the player models, as those are already in each client. The client itself generates the video based off this data."
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bt4t1f | how a amputee controls a bionic arm. | Technology | explainlikeimfive | {
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"There’s electronics that picks up the signals sent to the remainder of the arm and translates this to movement. When you tell a muscle to contract you send a very weak electric signal. The bionic arm will have EMG sensors that pick up the potential difference between a reference point and the signal source (usually the head of a muscle). Data from multiple sources is used to detect the desired movement.",
"There are actually a bunch of different ways to control a prosthesis! The prosthetist (doctor or engineer who specializes in replacement limbs) selects from a bunch of different systems depending on what the patient needs. The arm could contain a sensor that detects the motion of the arm and translates it into actions. For example, turning your wrist clockwise could close your fingers, and turning it counterclockwise could open them. This is a very common way to control bionics, since it's reliable, cheap, and works well with many different medical conditions and body shapes. Some arms use EMG sensors (electromyographics). The chemical reactions that power your muscles have an electrical signal, which can be detected and amplified. These are often given to patients with wrist amputations - the muscles that bend their fingers still work, but aren't connected to anything. The prosthesis detects these muscles flexing and converts it to finger motion. These arms are more complex - the sensors need to be placed just right, and the computer needs to be recalibrated often to detect the right muscle motion. Some arms directly connect to the nerves that control muscles or the brain itself. These are the most complex prosthetics - the truth is that our current technology, science, and medical knowledge isn't good enough to make these work very well. We know how the brain communicates with muscles, but not well enough to directly connect a computer to them. We've built some nerve-interfaced prostheses, but they're not really better than the alternatives yet. That said, there are a ton of discoveries to make and problems to solve. The most sophisticated modern prostheses combine EMG, neuroscience, and neurosurgery. The doctor gives the patient drugs and treatments to cause the nerves in the arm to grow longer. They then surgically \"rewire\" the nerves into the patient's chest, so they flex different parts of the pectoral muscle instead of fingers and the wrist. The prosthetic's EMG sensors detect these flexes and control the arm. This way, even if a patient's arm is totally missing, they can still control individual fingers.",
"When you want to move your arm, your brains sends an electrical signal to the appropriate muscle. So in a bionic arm these signals are picked up and move based on what nerve the signal was sent to. Eg if the forearms nerve moves the forearms, the bionic arm connect to this nerve moves when it detects something."
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bt6ejz | Why is the race to 5G such a big deal. USA, China and South Korea seems to all being doing well and are all nearing 5G. Why is it a big deal who does it "first" | Technology | explainlikeimfive | {
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"There isn’t really a race. It’s just political pandering and news sensationilization. There are benefits to having 5G connectivity, so each country is pursuing the technology independently. But there’s no huge prize to getting it first, as the USA should have learnt with LTE. URL_0",
"It also requires (in most markets) an entire overhaul of the existing networks. Most companies who offer internet services (Telecom included) frankly don't know what they have. An extremely large portion of cable is unknown and even what they do know if they may not know how many individual fibers/copper pairs are being used. 5G requires a fiber network in order to achieve the speed they advertise and a large amount of fibers (depending on the architecture). This is the main bottleneck right now as the Telecom companies are focusing on dense cities first and often times building in these locations is a nightmare and getting true 100% coverage is an extremely large, multi-year project. Source: currently working on a 5G build in the city of Chicago.",
"It’s because the US has done well in 3G and 4G patent licensing via Qualcomm’s efforts. If they lose to China in this patent war, it’ll cause a massive shift in economy towards the East. [Further reading]( URL_0 )",
"There is a concept of [ First Mover Advantage]( URL_0 ) basically the pioneer of a new market has certain benefits by being the first things like defining the standards and protocols that everyone else has to follow.",
"From what I understand the big difference between 5G and the internet as we currently know it is wavelengths. 5G requires a lot more accessible infrastructure (think street lights becoming hot spots) and once this is done then you’ll have super high speed internet everywhere and anywhere evidently 5G can hit fiber speeds wirelessly or so I’m told. So, I’d imagine the bureaucratic rat race is over who develops and owns that infrastructure to deliver the service. A lot of companies are seeing the government try and own it so they can own the next World Wide Web infrastructure. I’m sure China v USA falls in line w this vein of thinking.",
"There is an idea that 5G will allow to sprout a lot of new type of businesses. 4G was all about that broadband speed for us consumers. It appears that the consumer market is being saturated - there not that much profit to be made by drastically increasing speeds. The idea is to make mobile internet more reliable for so called - real-time and energy efficient applications (radio drains a lot of battery in our devices). These new applications will allow 5G network to be used for device communications in factories, warehouses. Previously businesses if they needed reliable wireless communication in their facilities had to order custom solutions. With 5G they will be able to just rent wireless radio from operator without big investments in infrastructure or hardware. The 5G standard is being developed in such a general way, that a lot of possibilities of entrepreneurs open up - therefore, a lot of new profit to be made. Also, whoever does it first can dictate what hardware will become standard for everyone else.",
"Nothing, I also work for a top tier carrier. It's all about money and hype. 5G is better than 4G so pay more for it. Technically the 3GPP (the governing standards body who determines the standards that all carriers follow) standards for 5G are not even complete yet. They won't be completed until the next standards release 1 to 2 years from now. What we have now is pre 5G standards or the beginning of 5G but carriers are marketing it as true 5G but it's not.",
"The issue here is not just 5G, is that China companies are starting to lead technology development in all areas (quantummechanics, telecommunications, security, space technologies... Basically everything). They already uncontestabily lead economic growth, and industrial production and are about to catch EEUU in most powerful army (on papper, still have to match EEUU army readiness). The point here is: EEUU has 2 options. Stop them now or let them lead the world. The extension, significanse and consecuences of \"stoping them now\" depends on a lot of factors."
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bt6fl1 | Why can’t I take a photo with my flash on at museums or historical locations? | Technology | explainlikeimfive | {
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"text": [
"It disturbs other people, and the harsh light can damage historical items such as old fabrics."
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bt7ut0 | Why do most video games only run on Windows and not Mac OS? | Technology | explainlikeimfive | {
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"The install base of Mac OS is incredibly small compared to Windows. The developers would have to do a lot more coding in order to make the game run on both operating systems, and that would cost money. The ROI would be far lower. Mac OS also isn't really optimized for gaming, so gamers don't tend to use it.",
"Because almost 90% of all computers use Windows. Most developers don't want to bother making games that less than 10% of computers can run. [Desktop OS Market Share]( URL_0 )",
"Eli5.. Consider a game like a cake. It's great but it takes effort to make the cake. You need specific ingredients and need to something to bake it in,like an oven. To make a windows cake, you use a specific ingredient and a specific oven. However a Mac cake would require different ingredients and possibly a different oven. Not every game maker has time or resources to fully develop a recipe for both a windows cake aswell as a Mac cake so they make the most popular cake: Windows."
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bt9kb0 | Why do flatscreen/LCD monitors display random colours and bizzare shapes or patterns upon being cracked? | Technology | explainlikeimfive | {
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"text": [
"Like others have mentioned, it can be the glass breaking and causing rainbows (from diffraction). You asked specially about Liquid Crystal Displays, the liquid can flow around when the display is (more accurately, the pixels are) broken. “Flatscreen” is a physical shape and not a method of building a display - these can have many methods. LCD is one type, the others will have different reasons for weird behaviors when they break."
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btak8k | Why does car window tinting only work one way, and maybe similarly, how do one-way mirrors work? | Technology | explainlikeimfive | {
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"text": [
"Both tinting and mirroring work both ways. The only difference is that if there is a significant difference in illumination in one side against the other the transmitted image intensity outweighs the reflected or vice versa. If you are outside on a sunny day, it's very hard to see into an unlit room through an ordinary glass window, but it's crazy to see out. At night with the room lights on you can see in but people I side don't see much out of the window. In a car with tinted windows, the illumination inside is usually light coming in from outside through the tint. So things inside are not strongly illuminated and are dimmer than reflections in the windows of things outside.",
"Both window tinting and \"one-way\" mirrors actually work in both directions - the difference is in the relative light levels on either side of the glass. Say you have a one-way mirror which reflects 90% of the light that hits it, letting 10% through. On one side of the glass you have an interrogation room with a light level of 100 units, and on the other, a darkened observation room with a light level of 10. Ignoring the glass, people on either side can see fairly well, because the human eye adapts extremely well to a very wide range of light intensities. The light from the interrogation room hits the mirror. 90% of it is reflected back - that's 90 units. 10%, 10 units, goes through to the observation room. The light from the observation follows the same rules. 90% (9 units) is reflected back, and 10% (just 1 unit) goes through to the interrogation room. Someone standing in the interrogation room sees 90 units of reflected light from the mirror, and only 1 unit of transmitted light from the observation room. The reflected light is so much stronger than the transmitted light that they basically only see their reflection. At the same time, someone standing in the observation room sees 9 units of reflected light, and 10 units of transmitted light from the interrogation room, meaning they can see the interrogation room pretty clearly. --- Tinted glass works the same way, it just absorbs light instead of reflecting it. Because the inside of a car is usually darker than the sunlight outside, the view through the glass from outzide is too dim to make anything out, while the brighter light on the outside can make its way inside perfectly fine. If you open a door and let direct sunlight inside the car, you can see how the tinting becomes much less effective! (Sorry for the maths, I did my best to minimise it)."
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btf8fp | How does the voice of performers like Michael Buble come across so evenly despite the varying distance between the microphone and his mouth? | I imagine some of this is done in post-production (for recorded video), but what about live? He is constantly moving his microphone all over the place. Happens a few times during this song, plus lots of his other performances. [ URL_0 ]( URL_0 ) | Technology | explainlikeimfive | {
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"Great vocalists have impeccable mic technique. When he’s pulling the microphone away his voice is louder. And when it is closer his voice is softer.",
"I used to do live audio for events and we are diligently paying attention to volume levels so we can adjust the output very quickly to make it as even as possible. I imagine for something like this, they would have very well trained soundboard operators to make sure the audio was clean"
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bthytz | Why does pressing harder on a TV remote with near flat batteries, seem to work better? | Technology | explainlikeimfive | {
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"As the batteries die, they push out lower voltage. The buttons are basically conductive dots that bridge a contact under the button and complete a circuit, making the led flash in a certain way to tell the TV what to do. Pushing harder can make a better contact, allowing the led to light up \\ flash brighter when the batteries are low."
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btiawf | How are amputees able to control and move prosthetic limbs right out of the box? | Technology | explainlikeimfive | {
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"There are two kinds of prosthetics. They both have different goals in mind. For example, a cosmetic prosthetic limb, called a cosmesis, is designed with appearance in mind rather than controllability. Advanced plastics and pigments uniquely matched to the patient's own skin tone allow a modern day cosmesis to take on an amazingly life-like appearance. Even details such as freckles, hair and fingerprints can be included, bringing the cosmesis to the point where it's nearly indistinguishable from the original missing arm or leg. Other prosthetics are designed to actually be somewhat of a replacement in functionallity for the amputee. I think your question aimed at the prosthetics that aren't body powered and appear to have a mind of their own. These devices actually listen to muscles remaining in the residual limb that the patient can still contract. Because muscles generate small electrical signals when they contract, electrodes placed on the surface of the skin can measure muscle movements. Although no buttons are physically pressed by the muscles in this case, their contractions are detected by the electrodes and then used to control the prosthetic limb. Scientific term is myoelectric prosthetics;) I hope my answer could help. Have a good day!"
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btiurv | Why do videos from the early internet have such weird audio quality? | Why is it that some media (early Homestar Runner, most Neopets stuff, the old BIC games, etc.) have such weird audio? I can't really explain it but it's like sort of echoed, kind of muted and super sharp at the same time, and sort of digitized. | Technology | explainlikeimfive | {
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"Bad, early file compression algorithms. Back in the day average internet speeds were very slow compared to today, and the need for small file sizes combined with early compression algorithms, leading to a serious loss of detail."
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btj5jk | what determines the type of batteries an electronic is assigned to? AAA, AA, the circle ones, etc | Technology | explainlikeimfive | {
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"Two factors are in play: 1) The form factor of the device being powered. 2) The power requirements of the device. AA, AAA, AAAA, C and D are all 1.5 volt regardless of their size. CR2032 (the circular button shaped battery) outputs 3V and 9V doesn’t need explanation. If you have a remote control that requires 6V to power the electronics inside of it. You’ll need to use 4 A-D batteries (1.5V + 1.5V + 1.5V + 1.5V = 6V). D and C batteries are too big for remote controls, but A type batteries are just the right size. Whether the remote uses AA or AAA or AAAA depends on the shape of the remote, but it can be an arbitrary decision in many cases. If you are powering a flashlight, you might opt for C or D batteries since form-factor is less of an issue. Four D batteries in sequence will output 6V, just as four AA/AAA batteries do. However, because D batteries are bulkier they have more juice. This will makes them last longer inside a flashlight as opposed to 4 AAA batteries, which would also fit inside a flashlight and power it, but not for very long.",
"They look at how much power the device needs to consume, and try to pick a battery big enough to power it for a conveniently long time, but small enough to avoid making the device too big/heavy."
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btjyom | How do those machines at Disneyland that write your name on the mouse-ear hats work? | Technology | explainlikeimfive | {
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"Magic! Just kidding. It’s an electronic embroidery machine. They can embroider anything, like even logos. They aren’t unique to Disney World. In regards to the cursive, the software probably has all of the letter transitions programmed in.",
"Some fonts have 'ligatures', special glyphs for particular combinations of two letters. E.g. classically for 'fi', the dot of the i might be swallowed up by the end of the curve of the f. It sounds like the font they use has a ligature for 'id'."
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btkdo1 | Durag, is it just a fashion accessory or does it have function? | Technology | explainlikeimfive | {
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"text": [
"**Waves** are a hairstyle for curly hair in which the curls are brushed and/or combed and flattened out, creating a ripple-like pattern. The hairstyle begins with a short-cropped haircut and frequent brushing and/or combing of the curls, which trains the curls to flatten out. Pomades and moisturizers can help hold the hair in place while preventing the hair from getting too dry. A durag is worn to preserve moisture while compressing the hair and holding it in place."
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btn8sz | How does a transformer work? | Edit: I meant this [one]( URL_0 ) | Technology | explainlikeimfive | {
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"When you move a wire though an electromagnetic field you can induce a current in the wire... The same works the other way where if you \"move\" the electric or magnetic field relative to the wire it can induce a current in the wire. As well, a current going through a wire will create its own electric and magnetic fields. Using alternating current (where the direction of the current will flip proportional to its frequency... So if its 60hz then it will change direction 120 times per second) you can create a changing electromagnetic field, if you have 2 wires close together you can induce an alternating current in the other wire. To better induce such a current you add coils. Edit: wrote this really early in the morning local time"
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bto39d | How does making the '8' sign in Google Maps improves the compass accuracy? | Technology | explainlikeimfive | {
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"The compass in the phone does not work the same way as the old whiskey compass. Both are trying to locate the direction of the magnetic field but where a whiskey compass will have a needle that spins around until it points in the right way the phone compass is stuck in place and can only measure the magnetic field in two directions. The problem is that there may be different factors that changes the readings of the magnetic field. So in order to really be able to find out what direction you are pointing it needs to compare the current reading with the readings in all directions. When you spin the phone around it can take readings from multiple directions. So that if there was an offset in one sensor making it read a stronger magnetic field then there really is it can see that it is not affected by where you point the device and can therefore ignore that offset."
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btrs6n | How did large congregations of people hear speeches (i.e. Lincoln's address, and countless other older speeches) without the use of microphones? | Technology | explainlikeimfive | {
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"If people are quiet, and there is no traffic or other sources of noise nearby, the voice of a single shouting man can be clearly heard for quite a long way away. In addition the large congregations were usually held at big amphitheaters which are specifically designed to help the sound from the stage carry outwards. The stages usually had reflectors and resonators at strategic places to make this happen. Where there were problems hearing the people speaking they would use megaphones. These are large cones that a speaker could shout into in order for his voice to become louder and more directed so that more people could hear them. Popular speeches would also be written down or memorized so they could be retold. A lot of the people attending political congregations would be campaigners who would go back to their home towns and recite the speech word for word so that even more would be able to hear it.",
"We’ve actually known about audio engineering for quite a while. Understanding that audio waves bounce is why medieval cathedrals were constructed the way they were, to maximize the echo. If everyone agrees to be quiet, the echoes amplify sound. A really cool American version of this is at the Old South Meeting House in historic Boston. In the 1700s, they were able to understand echoes well enough to come up with a manual amplifier, namely a solid disk over the lectern.",
"I've forgotten the actual name of the thing, but I once stood as a tourist in the back of an enormous Mormon meeting hall in Salt Lake City and was able to clearly hear a person speaking from the podium in a normal tone of voice without amplification. It was very impressive architecture.",
"Some people have powerful voices, and politicians and orators would practice and take lessons to speak in a way to be heard by crowds. Benjamin Franklin did an experiment in which he kept backing away from a preacher addressing an outdoor gathering. When he got as far away as he could, and still hear the speaker, he calculated how many people could stand in a circle that big. It turned out a speaker could address a crowd of 5000 or more without amplification. There are early recordings of singers and orators who were used to theaters and auditoriums without amplification, you can hear that they are belting it out in a way you don't hear anymore.",
"There were almost no machines. A person in a field could yell a message for many KMs. Everyone at Gettysburg respected Lincoln, so they all shut up.",
"I always get a giggle out of those pre-battle scenes where the hero/commander rides up and down the front line, encouraging the troops with a perfectly written charismatic speech. Men are lined up 100 rows deep and 1000 columns wide. But nobody can hear him beyond row three and since he's riding up and down the line, all soldiers in row 1 can hear is garbled: \"Men! Today we... hacked to death but... they cannot take... Forgotten!\"",
"So I know of old churches that have \"speaking stones\" they were stone slabs that hung over the speaker to reflect their voice to give more clarity and volume to the audience. Humans have found lots of ways to amplify sounds beyond microphone/speaker technology.",
"A combination of ways. First off, you pick a venue with great accoustics. We've known since the middle ages how to design spaces in such a way as to make what is being said/sung in one spot easily audible throughout. I've sung unmiced in cathdrals older than the western world and been heard fine. Also training. My background is in music, and as a vocalist, I have trained myself to enunciate clearly and project the sound. Someone making speeches would recieve similar training."
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bts4a5 | How does a simple, cheap sensor light know how long to stay on? | I installed a cheap motion sensor LED light in our fridge and wondered how it was "programmed" to stay on for one minute after sensing motion and whether this time could be changed when it only has a motion switch and on/off switch. | Technology | explainlikeimfive | {
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"A design like that today likely use a simple micro controller that is a very simple computer in a single chip. The can be as cheap as 3 cents each for as small orders as 100 controlled for example [here]( URL_0 ). They can only be programmed once so you cant change what they do. It could be som dedicated timer chip that is used where it is the values of other components on the board that determine the time it is on like a classic 555 timer that you can get for 6c [here]( URL_1 ) Then you could change it by replacing resistors and capacitors or even just bypass it to only light up when motion is detected. IT is in theory possible that some more advance microelectronic is used that can be programmable. It can even be a dedicated chip that is just for that purpose that cant be changes. & #x200B; So the answer is it depends but I would be surprised if it could be done without replace some components on the board. So you would need to know hot to solder surface mounted components. I would say that if you need to answer the question here how it can be done you do not have enough knowledge to do iy yourself without learning about electronics. But then you likely could changed or just replaced some part and add your own control logic after you purchased the equipment. But if you would like the change the functionality time simplest and cheapest way is to look for a motion actives light that you can timing setting for and by that"
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bttjop | How do hackers use brute force attacks like dictionary attacks if I get locked out of my account after 3 failed attempts? | Technology | explainlikeimfive | {
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"Usually they do this either on systems that don't have such lockouts (to prevent just those kinds of attacks) or they steal an encrypted database and can try those attacks on them at their own leasure.",
"Those systems have been put into place to prevent brute force attacks, they aren't everywhere. Also, websites frequently store passwords, etc, in an encrypted database. This is supposed to stay private to their servers, but sometimes those databases get stolen. Once the database is stolen, it is just a file -- the hackers have a copy on *their* computer, so they don't put any rate-limits into *their* software, which they use to attack the database. This is where they can really go crazy with the brute-forcing.",
"They can use proxies to make the entries appear from a completely different system, or sometimes abuse different login methods to that website. For example, awhile back, while Twitter itself DID lock you after multiple failed attempts, you could attempt to login via TweetDeck or Mobile Web Twitter an unlimited amount of times."
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btuzxe | Twitter is rampant with bots, how do they get past the whole "Are you a Robot" section? Does this make "Are you a Robot" questions useless? | Technology | explainlikeimfive | {
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"Twitter has several programs, called clients, that can send, like, delete, retweet posts, and do most of the things you can do on the site. The official ones are written by Twitter and include the website, and apps for mobile phones. However, the company allows others to make clients; someone wanting to make a client just needs to fill in a survey explaining why they want to make their own Twitter client. This survey is reviewed and is either approved or rejected. Twitter clients communicate with Twitter using something called an application programming interface (or API). When you ask Twitter about making a new client, if they approve your request, you'll get a unique username (key) for this API. Since the API is designed for programs, there's no \"are you a robot,\" check. Instead, Twitter uses various techniques to detect when a computer on the internet, a Twitter user, or a custom Twitter client (regardless of computer or user) is doing suspicious things. In response to suspiciousness, Twitter may reject a portion of requests until the suspiciousness stops. For example, if Twitter got a blast of likes from a user, or a large blast from certain machine on the internet, or an even large blast from a specific Twitter client, it'll start rejecting a portion of the like requests until the suspiciousness stops. If I was a mad haxor, happened to have the credentials to a lot of Twitter clients, had control over a lot of Twitter users, and had access to a lot of different looking machines on the internet, and distributed like requests across all of these, it may be difficult for Twitter to see these as suspicious: The posts I'm liking using this technique may actually be like-worthy. This is one of the ways bots circumvent Twitter's defences. Other less sophisticated ways involve old fashion approaches like getting a large number of humans to log into Twitter and carry on fake conversations and other interactions. Humans using the official Twitter clients may get \"are you human,\" challenges, but...they're human.",
"Twitter doesn't want to end all automated posting, scheduled postage, auto replies, etc. A lot of it is essential to running business online, but there's a fine line between automation and spam, so people who sell the tools to automate this stuff have to abide by twitters rules and api or risk being specifically blocked by them."
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btvtvg | How does voice recognition work? | Technology | explainlikeimfive | {
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"it Essentially breaks down the sound recording into very tiny pieces and compares each piece with a known sound or phonemes (sounds you make when saying specific letters like p or t). It then tries to match up these sounds into words and sentences that make sense in the context it was used.",
"In present days it's mostly like it happens in our brains: flow of sounds separated into set of different frequencies, then it's feeded to neural network, which remembers how each word sounds like (or, to be specific, how it's looks like a sequence of sets of frequencies). Neural network can compress, scale or transform sounds, so it can recognize words even if there's some noise on record, or if it's said with different pitch characteristic to person's voice, or with different tempo."
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bty4ke | Why isn't solar energy widely used? | Technology | explainlikeimfive | {
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"Solar cells, while the operating principle is simple, are very expensive and difficult to manufacture because of the ceramic materials required. (source: studying materials science and advanced functional materials at university.)",
"It's a combination of factors: 1. As a consumer: In the long term panels will save you on your bills but as an initial cost you need a massive capital outlay to install them. 2. As a power company, traditional fuel stations are more profitable. 3. The panels are considered ugly, a lot of people dont want them on their house 4. Historically they have not been particularly efficient. The panel needs a battery to be truly efficient and these are not easy to obtain on the open market (in the UK theres a company called social energy that has just started doing them in the past couple of years, prior to that..nothing) as you often need energy at a time when the sun isn't out. Theres some other stuff but that's the stretch of my memory for the moment",
"Power density is one reason why. To put out the same power as a fossil plant, the solar farm has a larger footprint.",
"Several reasons Solar panel can be expensive. Their efficiency depend on their location. ( [ URL_0 ]( URL_0 ) ) Here you can see that a solar panel in Scotland will produce about 40% of the energy produce by the same planel in some region of California. So even if it could potential be economically viable in California, it probably won't be in Scotland. & #x200B; But one of the two biggest problem is that it's that you can't control the production during the day. When you produce electricity you need to produce about the same amount as people consume, you can't produce much more and much less, otherwise you start to have problem in your system, blackout can happen, etc. So you need to be able to modulate your production and that something that solar can't achieve. & #x200B; When you look at the demand of electricity you see 2 peak demand, which is in the morning (between 6 and 9AM) and in the evening (between 4 and 8 PM). During those period the demand in electricity is higher than other time period. But if you look at the production of electricity by solar panel it's obvious that the peak production will around 12AM when the sun is at Zenith. So you basically produce more electricity in a period when you need less. To counter that there is several solutions. 1) You gonna need to pay company to use your electricity during you peak production. So for example a company that demand a lot of energy could receive subsides if they do their work mostly around 12AM. And you also gonna need to pay someone else to produce you energy during your peak demand since you don't have the capacity to do so. 2) You can build another more controllable power plant that you use to compensate you need during peak demand, but reduce their production around 12AM so that only solar power remain. This difference between 12AM and peak demand can be really high 3) You have enough battery to accumulate energy during peak production and use that energy during peak demand. When I'm talking about battery, he can't be a potential battery, which is use the energy to pump water in a reservoir and then use gravity pull that water through a turbine to produce energy. If an electric battery the price would be stupidly absurd, we are talking about several time the amount of battery currently in the country. If we are talking about potential battery then we are still adding a huge cost on top of the already expensive solar panel. & #x200B; Finally the last big problem is the unreliability of the system. It's not always sunny and you can't leave people in blackout every time there is a storm or a cloudy day. So again you gonna need to build more power plant that are only there in case there is not much Sun and you solar power production drop drastically. A solution is to put solar mostly in dry region. Take Las Vegas for example, it got a pretty good solar potential and it got about 292 days per year that are Sunny, that's about 80% of the time, which isn't too bad. This wouldn't solve the problem completely, but it would mitigate it a lot. & #x200B; Bottom line is that for several reason some that can be fixed, some other that can't, the price of solar power is just too high compare to other source of energy. The best indicator of that is LCOE or Levelized Cost of Electricity, which is basically the average cost per MW of energy produce and this cost include everything from construction to end of life. According to the US EIA ( [ URL_2 ]( URL_1 ) ) you can see that Solar power can have a decent cost. With a minimum of 40$/MW that's on par with some of the best natural gas power plant design, hydroelectricity or geothermal. The problem is that Solar price vary greatly depending on where you are. If you look at the average you can start to see that solar start to fall behind. At 60$/MW it can't compete with the average for some Natural gas design at 41-46$/MW or hydroelectricity at 39$/MW or geothermal at 41$/MW. But it's still better than several older natural gas technology, coal or nuclear power. The problem is that when you look at the maximal price solar start to fall even more behind. At 106$/MW it can't compete with some natural gas design at 48-55$/MW, but also nuclear at 82$/MW become more economic. & #x200B; The region where Solar is the most economic also tend to be the region will the less population. People live in humid region where agriculture flourish, which isn't the best places for solar energy. And putting a lot of solar power plant in Nevada to produce the electricity that New York will use isn't a really good plan, because you lose energy the longer you have to make it travel."
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btyct2 | How does an artificial neural network function? | Technology | explainlikeimfive | {
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"To build a neural network, you'd need some neurons, right? Well, the neurons we use are artificial neurons. They are mathematical machines that add up everything that comes in the back, and send it out to everything connected to the front. But when sending things out the front, they 'weight' each connection - in other words, they multiply it by some value. This allows each neuron to be different. If you connect them together, you get a neural network. If you have more than one 'layer' of neurons, you get a deep neural network, which can do more complicated things. If you have a loop in your network, you have a recurrent neural network, which can 'remember' things. To actually get it to do what you want, you take a network, but don't put in any of the weights. You then use an error function, that takes the set of weights for the network, tries them, and produces an 'error value' - basically scoring the network on how it performs. You can then use calculus to find the set of weights that produces the lowest error value. It turns out, if you choose the right shaped network for the right job, you get a pretty good neural network."
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btyend | Why does mobile signal fluctuate like this? | I'll be sitting in the same place with 5/5 signal and 4G internet. Then suddenly no signal at all. Then 2/5 signal and no internet. Then 1/5 signal and E internet. All within 10 minutes while sitting in the exact same spot. Why? Why does this happen? Thanks! | Technology | explainlikeimfive | {
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"The signal from the antenna isn't just a steady stream. It comes in waves, your signal depends on what those waves hit on the way to your phone and back again. Even moving your phone slighty can cause the signal to need going through a brick wall which will weaken the signal. There's alot of things that can cause it to weaken on the way",
"Phones also use algorithms to maintain signal but also to regulate battery usage. If signal is high in the area, they keep transmission boosting low. If the signal is low, it will consume more power.",
"You are constantly in between multiple cell sites. On average they are only a few miles apart. 1. If you happen to be in an area where the local site is too busy, you might get kicked off that particular tower so that they can service more voice traffic. 2. The local tower may be experiencing problems 3. There may be interference near the local tower, making you connect to a more distant tower."
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bu1enp | if every light emmiting diode is also a solar panel, why dont smartphones have the ability to charge via the sun? | Technology | explainlikeimfive | {
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"Mainly because they aren’t very efficient being used that way. It’s the same issue with microphones and speakers. They technically can be used interchangeably but a microphone makes a terrible speaker and a speaker makes a terrible microphone. LEDs are just better at emitting light. Also, solar panels are so bad at emitting light that the light they do emit isn’t even visible."
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bu1f06 | Why do diesel engines seem to outlast gasoline engines? Shouldn't they be built with the same stress safety factors built in and fail at around the same rate? | Edit: Specifically referring to passenger vehicles and consumer trucks, not commercial vehicles that i assume would be built to go much longer anyway. | Technology | explainlikeimfive | {
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"Gasoline engines usually operate at 25-50% higher RPM and have longer piston strokes further increasing piston speed which causes increased wear on pistons and cylinders as well as stress on the connecting rods. Both rods and pistons also have to be lighter to accommodate the higher speed. Diesel engines on the other hand have to be built stronger to allow higher compression ratios that can auto-ignite the fuel. That being said I doubt you will see very significant differences in lifespans of modern engines that are properly maintained. Maintenance is probably the biggest factor that increases lifespan of commercial vehicles that have to regularly undergo it while passenger vehicles don't necessarily do so. And this is probably where the greater robustness of diesel engines might allow them to better cope with lousy maintenance.",
"They actually operate at higher pressures and stresses. In some ways, this contributes to reliability because weak parts can't be used. It also makes them heavier. The reduced complexity of not having spark plugs and spark timing eliminates one set of failure modes.",
"Engine speed is a big factor. Cosworth built a 22,000 RPM F1 engine (that never saw a race because of regulation), but these engines only last for 2 races and they are SHOT. The friction, heat, and forces on the materials are insane. These pistons only have a 1.6\" stroke, OR LESS, and yet their titanium connecting rods will stretch and compress a 1/4\" per stroke. Metal fatigue, it's an explosive disassembling bitch. The stresses on diesel components is a factor compensated for by beefier construction of these engines. The steel is just thicker. And heat is compensated for by building them to looser tolerances, so the metal has more room to expand. In fact, it's very important diesels get up to operating temperature before undergoing their full duty cycle. & #x200B; So lower engine speeds have more favorable wear factors on engines. This coincides with diesel fuel - which is slow burning. Most diesels on the planet don't run beyond 1,300 rpm, and 5,000 rpm is just about as fast as you can go, because any faster, and you'd be dumping still-burning fuel out the exhaust ports. & #x200B; The biggest failure of a gasoline engine vs. a diesel is compression loss. Eventually, the wear between the piston and the cylinder wall will allow gas pressure to blow past and into the crankcase. This loss of pressure is a loss of power and an avenue to both burn oil and contaminate the lubricating properties of the oil. Gasoline engines have simple piston rings designed to be cheap. Gasoline engines in production cars just aren't worth it, when the rest of the car is also expected to rust and rot out. If your engine outlasts the rest of the car, you've over-engineered the engine and wasted all that money. & #x200B; A diesel, on the other hand, out of pure necessity, has a top piston ring that is 2 or 3 pieces, and is designed to compensate for all the soot buildup. The thing has a side effect that it can compensate for pressure loss from a compromised piston or cylinder wall by expanding into the fault and capturing the pressure. This has a huge, positive consequence toward the long term reliability of a diesel that just isn't factored into a gasoline engine. & #x200B; Commercial diesels aren't anything more special than consumer grade, what makes them last longer is that they're run MORE. A semi tractor pulling trailers across country put on miles and miles and miles and miles, running at regular, constant speeds. Engines like it when they run very consistently. It's stopping and going, starting and stopping, heating and cooling, and constantly changing loads and engine speeds that put the most wear on an engine. Making a quick stop to the grocery store and back puts more wear on your cars engine than a diesel that drives 900 miles non-stop. Notice if you take a road trip all the trucks in the oasis for the night that none of them have even shut off their engines.",
"I worked with British Austin and Morris cars when I started in the auto industry in the 1960's. The 1500cc \"B Series\" engines were worn out at 50-60k miles. Bore was elliptical, Timing chains, rod bearings, main bearings EVERYTHING had to be bored, ground, resurfaced etc. Datsun (now known as Nissan) licensed the design and I became familiar with it again in the 1970's usually in their 620 model pickup. It now ran to well over 200k miles with nothing but oil changes. IMHO it's all in material quality.",
"Diesel engines operate on simpler engine design than gasoline engines. They also run at lower RPM's since the fuel has more energy. So the main reasons small diesel engines typically outlast their gasoline counterparts is that they **run at lower RPM's and do not have spark plugs or complex timing mechanisms**. However, maintenance is key to a long lasting engine. Most diesel engines have turbo's, and that can often be the weakest link in a poor maintenance scenario. A turbo replacement can cost thousands of dollars. But if it triggers a runaway engine before you can replace it, then you'll be replacing the entire engine (A runaway diesel is caused by oil leaking from the turbo into the intake, and causing the engine to run on its own oil. The only way to stop it is to cut off the air intake)."
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bu7iw3 | Why is Starlink internet supposed to be good, when all current satellite internet is hot garbage? | Technology | explainlikeimfive | {
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"Current i tenet satellites are at 22,000 miles above the planet in orbit. Starlinks will be at 823 miles. Much less transmission time.",
"Because StarLink is going to be a constellation of low orbit, low latency, high bandwidth mesh networked satellites that will provide low ping high speed Internet everywhere in the world;. Current satellite internet is high orbit, high latency, low bandwidth point to point to point networking that is only available in fixed locations that a limited number of geostationary satellites can reach. The only things they have in common are they both involve satellites and they both provide some degree of access to the Internet."
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bu7kfb | In animation, what is rendering and why does it take so long? | Technology | explainlikeimfive | {
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"A lot of animation is done using wireframe and low-detail figures to sort of rough out the picture, to which high-quality details like lighting are applied. The process of applying those high-quality details is called \"rendering,\" and it involves a ridiculous amount of math and calculating all the effects at every point in a picture... and that has to happen for each frame. The process can take a very long time because of the sheer amount of data that the renderer needs to churn through.",
"Follow up question: what is the difference between movie animation vs video game animation?"
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buafn6 | How did old timey torches work? How did they burn for so long? How did the fire not just burn down the stick? | Technology | explainlikeimfive | {
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"text": [
"They were often wrapped in a cloth soaked in some sort of oil or pitch. Tar was common, so was tree pitch. Inuit cultures and Norwegians used seal and whale fat. It burned an extremely long time but didnt actually burn down the torch itself"
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budadx | How does a computer chip store data? | Technology | explainlikeimfive | {
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"text": [
"The chip itself only stores a very limited amount of data in what’s called a “cache” (there are typically multiple “layers” of this cache: L1, L2, and L3). These caches are used for data that needs to be accessed really quickly and frequently. Data can and will be removed from this cache if it’s not being used and new, needed data will be loaded in. You then have the more spacious reserves for data like RAM and disk. The same concept applies here. RAM is used for data that needs to be accessed quickly (but not as quickly as the data in the cache). Old/unneeded data will be revoked and more important data will be loaded in to replace it. Disk is the lowest layer and stores everything else. The lower down you go in these layers the longer it takes for data to be retrieved but the more space you have to store the data. The chip manages the finding/loading of data from these different sources and then does the necessary processing on said data. Hope that makes sense. Happy to answer follow up Qs."
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bue0w8 | What does it mean if 'secure boot keys are self-signed'? | I have spent close to two days trying to understand this and I just can't. | Technology | explainlikeimfive | {
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"In public key infrastructure (PKI), people will publish public keys that others are supposed to use if they wish to communicate securely with the individual. The problem is, how can you tell that a public key is valid? One way is that a central Certificate Authority (CA) will \"sign\" the certificate and attest to its validity. The rational is this: you don't have to trust me directly if we both trust a third party and that third party has signed off on us. The CA is that trusted \"third party.\" & #x200B; A \"self-signed\" certificate is one that is signed, not by a trusted third party, but by the same person who issued it. It's basically the person putting out their own public key and saying, \"trust me.\" This doesn't necessarily mean it is an invalid key, or that the person is not to be trusted, but there is that risk."
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buf7a5 | Why is is necessary to put phones into flight mode during a flight? What makes it critical during take off and landing? | Technology | explainlikeimfive | {
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"It's a complex issue. The FAA does **not** prohibit cellphone use on aircraft. They do however encourage companies to use their discretion and enforce policies that dictate usage of known safe devices. However, with thousands of different devices it's quite difficult to test all of them against the systems used by aircraft and determine, maintain and enforce usage of only those known to be safe. So it's pretty much individual airlines creating policies on the grounds of \"We can't verify every specific device and whether it interferes with the instruments on an aircraft or not, so we will blanket-ban them instead\". Most modern cellphones do not interfere with most modern aircraft. But the fact that it leaves the door open that some might interfere and create a safety issue, they simply ban them all.",
"> Was this also necessary before 9/11? Yes... but back then, cell phones just made calls and they were expensive per minute, so people had a very different mentality around cell phones and their use. The issue with phones/laptops at takeoff isn't so much a single device, but that if the rules allowed for use then you might have to deal with a high concentration of hundreds of phones on board that might interfere with signals or sensors."
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bugd5t | Why do the lights in aircrafts have to be turned off during take off and landing? | Technology | explainlikeimfive | {
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"epbry49"
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"text": [
"Because take off and landing are the most dangerous parts of a flight and most likely for a crash to happen. The lights have to be off and blinds up so your eyes are adjusted to the outside brightness/darkness aiding the speed and safety of a possible evacuation"
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buhvo8 | How do glass companies know how to mold an hourglass to have the sand fall precisely? | Technology | explainlikeimfive | {
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"They don't need to. They mold the hourglass to have sand fall approximately, add sand, wait the hour, dump the extra out and seal the glass. Its WAY easier to calibrate the sand than to calibrate the neck.",
"They don't. They manufacture one and figure out how much sand it needs for they time they want, once that is settled they can mass produce exact copies of the hourglass and use the same amount of sand in each. Minor variations will exist of course from minor variations in manufacturing or even the granules of sand.",
"I wonder if the more use an hour glass gets, the more out of time it gets. considering the sand is always getting smaller and finer, the more you shake it up, or mix it, turn it over, the (ever so slightly) more bits of sand rub up against each other and smooth off the edges, making each part smaller. also, the hole might get bigger too?",
"Wow I was legit just thinking this question in my head on the way to work this morning. Are we all thinking about it due to Aladdin being out in cinemas?",
"Related question: How are hourglasses made? Is it one piece of glass that is blown? Or two pieces that are joined in the middle/the choke point? When does the sand get added and through what opening (at the end or at the chokepoint)? Does anyone have a video how they are produced?",
"Bonus question with answer: Q: How do thermometer manufacturers know how to blow glass so that the alcohol or mercury expands perfectly to tell you the temperature? A: They don't. They get it close, then put the thermometer in fluids at a two different known temperatures then mark the glass. Then they pick the correct pre-made stencil to fit those two markings and paint the rest. (More or less) Bonus video: URL_0 You can rewind it to watch the whole manufacturing process.",
"These answers are probably right in practice, but you absolutely can model the sand as a fluid flow and determine flow rate based upon neck size. Then you can scale very easily to any time or glass size.",
"The answers are so often a thought experiment about how it could be done, rather than a definitive statement about how it is done.",
"Hourglasses have been very well studied over the last couple thousand years. Originally, there was a lot of trial and error as time-keeping became more and more precise, but now, you just have to look at what is already known. Companies don't have to reinvent the wheel when it comes to ancient inventions."
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buiebf | What makes burner/trap phones untraceable by the police? | Technology | explainlikeimfive | {
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"The phone is easy to trace, the person using the phone is not. There is nothing magical about the phones specifically, it's how they are used. Burner phones are bought by companies in huge batches, and don't require any plan or contract to use. So there's not a great way to know who is using that particular phone. They are also cheap enough to throw away and \"burn\" every so often to keep a pattern of use from being determined. Even if you could narrow down the phone was purchased at Walmart on a certain date, there wouldn't be a great way to know which one of the hundred that were sold that day is your suspect.",
"You want to know how to make them untraceable? (Well, super-not-likely-ever at least) 1) Walk to a raunchy gas station and pay a smoker you don’t know $5 to get you a prepaid card. Avoid cameras, avoid a gas station you commonly go to. If they ask questions instead of just doing it after a little chit chat, move on to another mark. 2) Grab a WiFi enabled device with no cellular that doesn’t have any information on it. Just wipe an old phone or whatever. Props if you buy a separate hard drive for a laptop to do it. 3) Head to a McDonalds or likewise store with limited or no cameras outside but decent connectivity. Just sit outside and smoke or enjoy the sunshine. Peak hours obscure traffic slightly better. Use that prepaid to get a VPN and bitcoins. 4) Go to the darknet (hundreds of guides online) and get a burner phone prepaid with minutes. Limited GPS capability, no camera (You can break it if it’s comes with one. Not hard) You can buy whatever else there too. Do not use an online name you have on the surface web, a password you had before, or any other information that reveals yourself. 5) Have it sent to an abandoned house or likewise address not connected to you. Easy way to check if they receive mail still is to send a fake hospital bill (rehab). Super available online. 6) When you receive the phone, reset it to factory defaults and ensure the SIM card is what the seller detailed. Be cautious, it’s best to buy very basic phones so you can tell if it’s been tampered. 7) Phone address book in a safe place when you switch phones. Don’t save numbers, don’t save texts, don’t take long calls. No calls if your situation allows. Never use names. Disable all extra features. Don’t use WiFi on that phone. 8) Be a decent dirtbag and wipe the phone, then smash and burn it. Dump it off in a construction site dumpster mostly likely at twilight hours (when people are most likely not to be there.) Switching phones monthly seems to work ok. Your situation may differ. If you need any more help PM me. Having privacy is a respectable endeavor for everybody.",
"They are traceable, but your name isn't associated to it anywhere. You don't have to sign anything to anyone, so even if they track the number or the gps signal, they still don't know who it belongs to.",
"The phone is bought at a physical location for cash. There is, therefore, no record of who bought the phone or who currently owns it. The phones are pre-paid with a number of minutes of talk time that is included in the sales price, so they already have a number and available air time(they can also have their minutes recharged, but that's more for people who legitimately buy them as a cheap option to have a phone when they can't afford something better- which is the intended use of such phones). While a phone's location can be tracked by cell towers (it's pretty simple, but not going to get in to how that works) the phone has to be turned on, so a smart user will also only turn the phone on when they are going to be placing a call, and will not place a call from a location that can be easily tied to themselves nor reuse locations with any sort of pattern that could be determined, or just throw the phone away and get a new one after one or two uses (this last being why it's called a burner phone- you use it and 'burn' it)."
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buieq9 | How do surgeons prevent you from bleeding out during surgery? | Technology | explainlikeimfive | {
"a_id": [
"epcknt6"
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"text": [
"Depends really. Aside from major vessels, not much blood is lost during a surgery. Tourniquets for limbs and careful positioning of incisions for more general stuff. Hollow organs, the major vessels, and scalp stuff all can involve a lot of bleeding if not done right. There's packing agents, clamps, and creating pressure that all help too. I've had people lose more blood from me putting in a breathing tube (accidental damage to a tonsil) than lost in some surgeries."
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bul2dc | Does leaving a phone screen idle save more battery then flipping it on/off? | Technology | explainlikeimfive | {
"a_id": [
"epe8wcw"
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"text": [
"The screen is typically the most battery intensive thing your phone does. The more time it's on, the more battery drains. Every second it's turned off saves battery."
],
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7
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buouwd | Why are most street lights and car lights orangish yellow and not white? | Technology | explainlikeimfive | {
"a_id": [
"epf50ui"
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"text": [
"Many street lights were/are sodium vapor lights. It’s a highly efficient light that just produces a warmer light as the byproduct. URL_0"
],
"score": [
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bur31f | What's the difference between a router and a wireless access point? | Technology | explainlikeimfive | {
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"text": [
"A wireless access point is a hub of a Wi-Fi network. It allows Wi-Fi capable machines to connect to that network. A router connects multiple networks together and routes messages between networks. For instance, it allows users on the Wi-Fi network to send messages to an ISP and out onto the wider Internet. Consumer networks are generally very simply laid out, so consumer APs generally combine both in one device. Commercial or institutional networks will more often benefit from separating them. For instance, if you have to have a large office space connected by Wi-Fi, you'll likely have multiple access points connected by wire to a single router.",
"Lots really. A wireless access point only connects devices wirelessly. It does generally not have a firewall or the ability to control traffic etc. A router is what connects a wifi network to the internet so it has a lot of functionality built in to protect the internal network from the internet. It also routes all the traffic between your house / office and the internet including hiding your internal IP range through a process called NAT (Network Address Translation). A router will be more expensive and this is due to the added functions.",
"To be clear, what you're likely referring to as a 'router' is actually a wireless router. & #x200B; **Router:** A network device that *routes* network traffic. It is usually connected directly to the modem or gateway that connects the network to the internet. It will determine if traffic needs to go to the internet or somewhere else on the local network, it also usually has some firewall features (It blocks unwanted or dangerous traffic). & #x200B; **Network switch:** A device that connects several wired network devices together. It is able to learn what devices are connected to each port and properly direct traffic to the correct destination port. & #x200B; **Access Point:** A device that allows wireless devices to connect to the wired network. & #x200B; **Wireless Router:** Typically a consumer network device that combines all of the above features. It is a network switch, router and access point all-in-one. These will sometimes also include modems."
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burok1 | How are games 'ported' to different platforms like PC, Xbox or PS? | Technology | explainlikeimfive | {
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"text": [
"Most of a game's code and assets are the same between platforms. The main things that have to be different are the bits that interact with the hardware or OS. Take graphics for example. On PC and Xbox you use the DirectX API to give instructions to the GPU. But PlayStation has its own API for that. So if you need to convert an Xbox game to PlayStation, you have to rewrite that code. Typically the code for a game is organised so the platform specific stuff is separated from the non-specific stuff. That way it's easier to work on a game for multiple platforms at once."
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