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ioqr2k | What are APIs and how do they work?, | I've read multiple articles and watched multiple videos but i don't quite understand how this works exactly Edit: Thanks for the explanations! | Technology | explainlikeimfive | {
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"APIs are like a phrasebook two different programs use to talk to each other. Each API is a phrasebook for a different program e.g. the Facebook API tells other programs how to talk to Facebook. Each program has its own phrasebook as you ask it different things than you'd ask another program. E.g. The Facebook API will tell you how to retrieve posts on Facebook; the Twitter API doesn't need a phrase for that as that's not something Twitter does. However, both phrasebooks will have a phrase to say \"I'm logged in as x account\" as both use account login systems. There are different kinds of phrasebook that use the same kind of protocol - REST or SOAP. This is like a shared grammar structure between the phrasebooks; the words might be different but the way you put them together is the same if they use the same protocol. For instance, REST APIs all use http protocols like GET, POST, PUT and use query headers and parameters. This is like how in English, we always have an order for putting nouns and verbs into sentences. The words we put in the sentence are different, but the way we organise the words stays the same.",
"Bob builds and sells lots of cars. John makes special tires that drive on sand. John will sell a lot of tires, if he can make them fit on Bob’s cars. Bob also has the opportunity to sell more cars to people who want to drive on the beach. So John asks for information about Bob’s cars- the size of the wheel well, the number of lugs on the wheel hub, etc. Bob is happy to give that information, because it would help both of them sell more stuff. The specs for Bob’s cars is an API- a set of proprietary rules, which third parties can use to interface with a product. I used a physical analogy, but APIs are specific to ~~the web~~ software. It’s what allows you to sign into Spotify using Facebook, etc.",
"An application programming interface (API) is a set of rules or instructions that can be used by a developer of another piece of software to interface (exchange information) with the primary software. Each one works differently and will use different programming languages but information is commonly exchanged in XML or CSV formats."
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iorhdl | How do touchscreens work? | Technology | explainlikeimfive | {
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"You're looking at two different types of touchscreens here. * Resistive touch: this is what your 3ds uses. In a resistive touchscreen, you have two flexible sheets coated with a resistive material, separated by an air gap, with a voltage applied to one of them. When you press the two together, the voltage is used to register where you're pressing. This is the reason you can use just about anything to press on a resistive touchscreen, because what you're using doesn't matter. * Your phone, on the other hand, uses a capacitive touchscreen, which relies on the fact that the human body generates a very slight electric field. When you bring your finger (or some types of styli or gloves) in contact with a capacitive screen, the combination of the voltage on the underside, the glass, and your finger forms something called a *capacitor,* and the phone can determine where that capacitor is, and therefore where you touched. This type of screen must be used with the correct kind of interface, which is why your 3DS stylus won't work with it."
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iorsx1 | How do password crackers minimize time spent shifting through symbol types? | I assume that the program starts with one type for all, finishes all possibilities, replaces one and repeats till its solved (1111 - > 9999 - > 111a..... till solved). By that logic a combination of the last listed/least common chars would take the longest. (which would be a known password to check earlier?) Is that just accepted and its better to use later listed/less common characters for a password or do they get around that somehow? | Technology | explainlikeimfive | {
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"Even when brute forcing passwords, you would almost never just start from some sequence and count upwards from there. If passwords were assigned completely randomly then that might work as a tactic, but passwords are often not assigned randomly they are made by people who follow very common patterns when assigning passwords. Most of the time you are cracking passwords you don't care about any individual account, you just want to compromise a maximum number of accounts for you to later use or sell. If you try a list of the most common passwords then you'll get a significant number of them. From there trying common English words with some variations will get you many more. If you're in the situation were you do care about one particular password, and it was set by someone competent in choosing random strong passwords then you are very unlikely to be able to brute force the solution.",
"So assuming that someone uses really simple brute force as you describe, then password consisting of the highest possible character (etc. 'zzzzz') would take the longest time to crack. But that's not a useful strategy, because such attacks are super rare and not very effective. Its much better to try to use some common passwords and its variations. Also if you can get many user logins, then you can take very common password (such as 'password'), and check it for all users. Some accounts will be cracked. Then you take second most popular and so on. Its good to remember that usually user is the weakest element of any system, and targeting users, instead of system will yield the best results."
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ios5i6 | ; what is a particle accelerator and how does it work | I'm watching the Flash for like the fourth time and i searched it up apparently its a real thing, but i don't understand what it is and how it works | Technology | explainlikeimfive | {
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"1. Take some particles with an electric charge (protons, electrons, some ions or such) 2. Use a whole lot of electromagnets to give them a big YEET along a channel or a ring 3. You accelerated a particle It's useful for slamming tiny, atom-sized stuff real hard into other stuff. Subatomic particle research (\"What comes out if we smash two electrons together *real* hard?\"), cancer treatment (\"Pew pew\"), semiconductor manufacture (\"Let's smoosh this stuff into that silicon crystal *real* hard so it sticks!\")",
"If you throw a drinking glass against a wall, it will shatter. The harder you throw it, the more pieces it will break into and the smaller these pieces will be. Replace a glass with a particle. A particle thrown against a wall at a ridiculous speed will break down into smaller and smaller particles. These smaller particles are building blocks. They are the ingredients inside stuff that we can't normally see. The particle accelerator is the thing throwing the particles. What scientists are looking for when they smash these particles is what the really really really small ingredients are.",
"It’s like a tunnel (a circular one) where they accelerate particles using magnetism to very VERY high speeds to eventually collide them, so that they can read the behaviour and contents those particles are made of.",
"Particle accelerators use magnetic fields to make subatomic particles travel at very high speeds. Like how a magnetic train track propels a bullet train, but on a sub-atomic scale. They often use this technique to make these particles collide. This allows them to study the behavior of certain particles and attempt to discover new particles like quirks."
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iougft | Why do speakers smoke when they blow out | I was watching videos about speaker blow outs and in almost all of them there was smoke coming from the speaker. | Technology | explainlikeimfive | {
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"The insulation in the speaker driver (electromagnet) is burning up. When a speaker blows out it's usually the driver that's given up; that's the part that's actually taking in electrical power and moving the speaker cone. In order to get as much wire in as possible (maximum power in minimum space) the wire insulation is thin. If it gets too hot it starts to burn up...smoke. And now you have a short in the coil, which means it pulls more power, which means more smoke. The whole thing quickly gives up.",
"Before the speaker blows the coil which drives the speaker diaphragm will be getting very hot due to the excessive electrical current flowing through it. That heat will continue, and eventually burn through the coating that insulates the wire. Smoke is generated by that material burning, but there is a second-order effect: after the coating on the coil wires has burned away, the coil becomes electrically shorted, effectively shortening the coil and drastically reducing its electrical resistance. As a result, the current in the wire spikes even higher, increasing the heating even further. This is a vicious cycle that continues until the wire itself melts, and basically all of the insulation is burned away. Smoke smoke smoke."
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iout4n | How does checking the “I am not a robot” box let the computer know that you’re actually not a robot? | Technology | explainlikeimfive | {
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"The I am not a robot box monitors how the mouse behaves. A robot would move the mouse in a perfectly straight line, while a human would move it in a less than perfectly straight line to the button. There would also be a difference in how quickly the mouse moves, and how quickly you click the button once the mouse is in location. If any of these comes out a little too robotic it can pull up a more complex check, like \"click all the pictures that have a car.\"",
"* The server checks a bunch of things about how you check that box like: * How long it takes you to check it. * The pathway your mouse takes from where it was to where the box is. * Was that path straight or did it curve? * Where exactly in the box you click. * Did you scroll at all first? * Eventually bots will get better at mimicking how humans click those boxes and something new will have to be used.",
"Simple answer: we don't know. ReCaptcha is owned and run by google and they (obviously) don't publish what data exactly is used to determine whether you're human or not. We can take some likely candidates such as browsing history, cookies mouse movement and keystroke behaviour, but no one except the google engineers know exactly. The likely answer is that they just take **all** the date they legally can about your behaviour and internet history, chuck into big 'ol machine learning algorithm, and then that thing spits out a number how likely it thinks that you're a bot",
"When you check the box it looks at a ton of signals to see if you've been acting lack a sack of meat. Scrolling, typing, moving the mouse, etc. Also, robots don't \"move the mouse in a straight line\". The whole \"robot\" thing is meant to be cutesy and funny for the sacks of meat, it's not a literal robot. It guards against bots that try to automate filling in the form. A bot would just mark the box as checked, not actually move the mouse, or even simulate moving the mouse.",
"also maybe we are just being fooled into helping to feed a machine learning for self-driving cars by helping them identify objects because computer-vision requires millions of tagged images to use as examples for artificial intelligence"
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ip2mm0 | How does an air fryer work? | I always see people use this but I have always been curious about it... | Technology | explainlikeimfive | {
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"It's just a convection oven, which is just an oven with a fan in it to circulate air. No they do not actually fry food (nor do I think the food that comes out of them tastes as good as fried)"
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ip7jz1 | How did people navigate when it was cloudy and you couldn’t see the stars? | Technology | explainlikeimfive | {
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"It was called dead reckoning. You took your last known position, estimated speed and course and plotted your new position. When the weather allowed you plotted a corrected position"
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ip7vv2 | what does a compressor (in audio production) do? | i’ve been working with DAWs and producing my own music for years, but i have honestly never gotten a straight comprehendable answer as to what a compressor does. | Technology | explainlikeimfive | {
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"A compressor evens out the output volume level of an input device such as a microphone or guitar. Screaming into a microphone and whispering will come out at the same volume when compression is added. This is particularly important when making live music as the singer's heads do not stay a steady distance from the microphone. The more compression added to a signal the more the output is evened out.",
"Okay. So. A compressor takes the amplitude (think volume) of a wave and reduces it, thus having the effect of making the loud parts a little bit softer. It has four basic factors. Threshold, Ratio, Knee/delay, and Gain. Threshold is the minimum volume it will pay attention to. Anything below that it doesn't touch. Ratio is the slope of the line that determines the amount of reduction. So a high ratio means that loud stuff is made quiet, but REALLY LOUD stuff is made just-slightly-over-quiet. Knee is basically hard or soft. A soft knee is just a smoother transition at the threshold, and the delay is how long it takes for the threshold to kick in. And finally raising the Gain raises the volume going into the entire process, which makes everything loud, then compresses the loudest bits, so the end result is that the quiet stuff is medium and the loud stuff is medium. Whew. So the short answer is that it squashes the dynamic range of volumes so that loud and soft are both closer to medium. Why use this? Lots of reasons, including improving the sustain on your electric guitar, helping push vocals to the front of a mix, and fixing the drums so a kick isn't too boomy."
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ip8kvz | How do they keep making faster cellular networks (4g, 5g, etc.)? | Technology | explainlikeimfive | {
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"Higher frequency wavelengths transmkt more information in a smaller time frame. But they go less distance and get obstructed easier. So we develop better stronger transmitters to go a proper distance. And we develop better transmitters in phones to accept the signal.",
"5g is 5th generation. Every carrier owns or rents a spot on its countries bandwidth platform. They all name their new technology 5g but in reality they're all using different transmitters/receivers that are able to talk to one another using a protocol and industry standards. 5th generation cellular is just a name to give a bunch of standards that 5th generation should hold up to. It is different from your 5g wifi. Not the same at all although it's confusing to someone that does not know. Cellular transmits over a much broader area of the wave spectrum and is similar to 5ghz wifi in name only. Just as coding for computers advances so does the way cellular talks over radio waves. Some of the 4th generstion transmitters are being updated to 4.7-4.8 capabilities by updating software and a few components but will be called 5g but not really be 5g. They are fake 5g and lobbied the Gov't to give them the right to use the name because to them it's close enough. You will see this in the suburbs more often like we saw happen during the 3rd gen to 4th gen rollover about 10 years ago and the HSPA+ standard. In 10 years from now they will start rolling out 6th generation cellular because they need the next 5 or 6yrs to lay the foundations to what is needed and how to do it. Then it's up to private companies to figure out a way of talking. Industries all just keep moving forward based on competition and the desire for need/want."
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ip8tq0 | How can a 256gb sd card have more storage capacity than a 16gb sd card even though both sd cards height and width are identical? | Technology | explainlikeimfive | {
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"TLDR: a 16GB card is the same as the 256GB with enough flaws that only 16GB are usable. --- Basically, when we make flash memory (like on a USB flash drive, or an SD card), we make it on a silicon chip. This silicon is an artificial crystal grown in a lab, but the bigger the chip the more likely there's a flaw in it somewhere. Flash memory tends to be cheap, so we're already not using the expensive crystals, so there's a lot of flaws. This means that if you make a 256GB card, there's a good chance that it won't work. But if you're clever, and turns out computer engineers usually are, you can still use *some* of it. So you take all your 256GB drives, and you test them, and any that aren't perfect you say are now 128GB and lock off the faulty sections. Then you take the 128GB drives, and you test those, and any that fail you say are 64GB, and so on and so forth until you get down to the smallest size you want to make. This makes for a pretty efficient process because you're not throwing away many chips, because it's pretty rare that you'll get a chip so broken it doesn't work at all.",
"Basically, we've gotten better at making SD cards, found tricks to add more information density, used tech not available when the 16gb was first made. [It's kind of an application of Moore's Law.]( URL_0 ) We make them the same size so as to be compatible with SD card readers.",
"It also comes down to the size of the actual components inside the sd card. The SD shape is standardized, but the inside of the card isn't. Some just have a little tiny board, others have a larger board. Some of that comes down to the year when it was made. If you crack open two 16gb cards, one brand new and one 10 years old, they're going to be different inside. Most likely the new one has empty physical space.",
"Imagine you invented a new Thing. What your new invention does is, you write a number on it, then plug it into a machine, and the machine knows what you wrote on it, and displays it, the same way that a computer does! We will call your new invention: The Writer-inator! Hopefully lots of people will like it and buy it from you, and you can make lots of money to do whatever you want with, if that's what you want! But hold on!... Now, you have a new problem: Because your Writer-inator is such a brand new invention, it's so new that computers and machines don't even know what it is yet! There's no way for you to even be able to plug your brand new Writer-inator invention into a machine or computer yet! So you have to also invent a way for your Writer-inator to be able to plug in to another machine or computer! Think of it this way: When you plug machines at home into the wall, like your vacuum cleaner, or your can opener, or even your computer, they all have plugs at the end with metal sticks that stick out from the plug that you hold in your hand. Have you ever noticed how they all look mostly the same? Sure, some of them just have 2 flat metal sticks sticking out, sometimes they have 3 metal sticks, when there are 2 flat ones and a third rounder stick. But think about where they plug into on the wall. They almost always fit, no matter how many sticks are sticking out! The plug-holes are perfectly matched up to the plugs! There are 2 flat holes for the flat sticks, and most of the time on the top or the bottom there is also a rounder hole for the third stick to slide into. But wait! What if you or someone else builds a new plug, and it is bigger or smaller or in a different shape than the ones you normally use? Well then it won't fit in that normal plug hole anymore, will it? You will have to build a new kind of plug hole for your new plug to plug into, right? What happens if many, many people build many, many new machines, and all of them have different kinds of plug holes? Everybody's new plugs can't fit in anybody else's new plug holes, can they? No, they can't! But if you wanted to use these new machines, you would have to have at least one of each new plug holes for each of these new machines! That would take up the whole wall, maybe even the whole house! Imagine that! All the walls in your whole house, completely full of those plugs and plug holes! Where would you hang your pictures? Any furniture and bookcases would have to be moved over and over again because they're always in front of another plug that you need to use for another machine! (Just in case you are thinking of using the plug holes to hold nails in for holding pictures: Bad Idea! Don't Do It! That could give you a very nasty ElEcTrIc ShOcK!!! Never stick anything else into a plug, even if it's not metal!!!) So, if you don't want to have your whole house full of walls that are all full of plugs and plug holes everywhere, what are you supposed to do? Why, the same thing that you already have today, of course! You can pick just one of those plugs and plug holes, and make a new rule that says all new machines that have to plug into the wall, MUST be shaped in a way that will fit into this ONE plug hole that you chose! That way, you can have just a few plugs on the wall in a room, holding all the plugs from the many machines, instead of many, many machines all going into many, many different plugs holes all over the walls. Now, with just ONE plug chosen, you have room to hang your pictures, and you won't have to move your furniture and bookcases over and over again! You know that rule you made, about choosing ONE plug hole, and about how ALL plugs must fit it? Those kinds of rules are called \"standards\". Standards are a very good thing to have! They help us avoid all kinds of problems very much like the ones about having plugs all over all of your walls! They also make sure things will work the way they are supposed to! Now, remember that new invention you made, the Writer-inator? Remember how it's so new, that machines and computers don't even know what it is yet? They don't even have a way for you to plug in your Writer-inator! So what you do is, you make a standard! You make a new plug on machines and computers for your brand new Writer-inator to be able to fit and plug into! OR you can decide to make your Writer-inator to be able to plug into a plug-hole that is already there! You then decide to make it a rule for all the Writer-inators that will ever be made, must all be made to have the same size plug, so they can all use the same kinds of plug holes, without putting brand new plug holes all over your computers and machines. TaDaaa! Now it works! You write on your Writer-inator, you plug your Writer-inator into a machine or computer, and it shows you what you wrote! After a while, you discover a new problem with your Writer-inator. What is the problem? You can only write 1 letter or number at a time! There's not a lot of space on your Writer-inator. You can't make your Writer-inator bigger, because they're supposed to fit into these plug holes, remember? If you made them a different size, they would not fit anymore. You do not really want to make a new one with a different size, and different holes to plug into, or else you start running into the same problems as before: you'll have too many plug holes all over, and too many plugs to plug into them! It's much better to have as few different kinds of plug holes as possible, so if you invent a brand new kind of Writer-inator, you should keep using the same plug holes that you have been using. So what do you do if you want to write more than 1 letter or number at a time on your Writer-inator? You think about it for a while, and you finally come up with the solution! All you have to do is to write smaller on your Writer-inator! Imagine if at first you used to write letters and numbers # THIS BIG! Now, you only have to write them THIS BIG! This is half the size of the first one! You can fit 2 letters and numbers on your Writer-inator now! Of course, over time, you'll come to think, \"2 letters and numbers still isn't enough! I need to be able to fit even MORE onto my Writer-inator! I'll have to figure out how to write even SMALLER! And then after a while, you start writing on your Writer-inator using letters and numbers only ^(THIS BIG!) That is pretty small, only half the size of the last one! That means you can now fit 4 letters and numbers at once! Where you used to only be able to write one letter at a time like this: # A You now can write 4 letters at a time like this!: ^(AZ09) But that's still only 4 letters! So you keep thinking and figuring out how to write smaller, and smaller, and smaller, and smaller, and even smaller... until finally you've figured out how to write 256 gigabytes of information on the SAME SIZE Writer-inator that you started out writing only 1 letter or number at a time on!!! You still have your old Writer-inators that can only write 1, 2, or 4 letters at a time. Sometimes people decide that they don't really need to be able to write 256 GB, they'd be willing to just stay with 16 GB. All the Writer-inators are still in the same size and shape so that they can fit into the machines and computers that are reading them. That's why SD cards stay the same size even though the newer ones can hold more data. Some will hold only 16gb, some will hold much more. But they all plug into the same thing , so they all have to stay the same size and shape."
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ip9gxg | Why is color calibration so important/extra cost for monitors yet never seems to be mentioned with TVs that are solely meant for consuming media? | It just doesn’t make sense that such a selling point of monitors lately has to do with color calibration to ensure what you’re creating/viewing is “how it’s intended to be viewed” yet no mention ever seems to happen in regards to the screens a majority of people view content on such as TVs or even phones/tablets? | Technology | explainlikeimfive | {
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"The problem can be users expectations in printing. They view a document in their monitor, and want to simply press print and have matching colours on the output. A calibrated monitor is useless without a calibrated, postscript, pantone enabled printer, with the output profile of the calibrated monitor stored in the print driver. Then again, near enough is good enough for most users.",
"It’s a good question. it’s sort of the same principle as audio: if you can make your mix sound good on sonically-flat reference monitors, chances are, it’ll sound pretty decent on everything else. You’re basically starting from such a “neutral“ place, that once various makes and models inevitably shift in various directions visually or sonically, it’s not being pulled to such an extreme that the media then degrades. This is why we have commercial loudness and brightness standards for example. Since we CAN’T account for every make and model out there, which are often more “colored“ in both senses than professional equipment, the safest thing is to just make something that’s sort of a “triangulated(?) happy medium” between all of it."
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ipa1o1 | How do fire extinguishers work? | What’s in them? Do they have a propellant like aerosol cans? Are the chemicals in them bad for the environment? | Technology | explainlikeimfive | {
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"It depends what they're meant to put out. And yes, almost all have propellant in them. Super basic: contain water, which you pump. I remember my elementary school having these but I haven't seen one like this in a long time. Downside - if you spray this on an oil fire, you just smear burning oil around because of the oil-and-water-don't-mix thing. Downside - if you spray this in a typical building, now you have puddles near live wires. Better: carbon dioxide. This is heavier than air so it settles to the ground and smothers the fire. Downside - if there are casualties lying on the ground, it can smother them too. Better: dry chemical. These spray powder all over, and when the powder gets hot it releases inert gases that smother the fire. Better: AFFF, aqueous film-forming foam. Used for oil fires, it creates a skin on top of the oil that keeps oxygen from getting to it. Downside - the puddles and live wires thing. Airports use AFFF because it actually has a hope of working on a jet-fuel fire and there aren't too many live wires on runways. Better: Halon. This is a stable, heavier-than-air gas that snuffs out fires. I'm not exactly sure how these are better than carbon dioxide, but there must be something because they're expensive but they still get used. Halon's definitely not great for the environment - it's a CFC. I'm not sure about the dry chemicals or AFFF."
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ipbndt | Why is an MRI machine so big and take so long to complete? | Technology | explainlikeimfive | {
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"It's big and noisy because it needs giant magnets and coils. MRI scans take a long time because you can only gather data from one frequency at a time. It's like if you are trying to record some speech. A CT/X-ray scan is like a microphone. It listens to all frequencies simultaneously and is therefore very quick. But an MRI must first listen to one frequency, and then another, and then another, until you have enough frequencies to recombine them into the final soundwave.",
"An MRI machine creates a powerful magnetic field that will cause the proton within hydrogen atoms to resonate at a specific frequency. This resonation will release radio waves which can be detected. By carefully varying the magnetic field gradient across the body the relative concentration of hydrogen atoms can be mapped and with it an image of interior structures of the body. It is so big because the mechanisms to do this miraculous feat of engineering take up space. It is like taking a wrapped Christmas present under the tree and by shaking it reading the card attached to the gift from how it rattles. You are asking why that takes a while to complete."
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ipbrvg | where does Captcha come from? | Do they have a database of pics to reuse? What about text-based images? Who picks out any of these? Are there employees specifically taking blurry photos of trucks, traffic lights, old textbooks w/ misspelled words etc. to be used in Captcha tests? Who even runs the whole thing? | Technology | explainlikeimfive | {
"a_id": [
"g4j0o4j"
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"text": [
"The car/road related pics are made by cars and you're teaching a self driving car AI when you're filling in a captcha"
],
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8
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ipbvcx | What are network ports and how do they work? | Technology | explainlikeimfive | {
"a_id": [
"g4j1ljc"
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"text": [
"If you think of your computer as an apartment building, you can think of ports as the apartment numbers. You order a package (data) to the building (your IP), it needs to know which apartment it goes to (200). It gets more complicated. Like some apartment are designated (by default) to receive certain things like pizza, strippergrams, and bouquets of flowers. While others send out random letters to pen pals with the full address so, when they respond, your prison buddy knows where to send it. Edit: to clarify, your router acts like a door person and keeps tracks of which apartment# sends out which package, so this is where the instances where some things use a random port"
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ipcp7d | Why is Windows forcing the user to update itself all the time, even though nothing is really changing? | Why Windows forces its users to update the software all the time? It takes like an hour or two of my computer being completely useless when this happens. With every subsequent update I can notice my computer working considerably slower, yet I do not see any changes whatsoever. Why is that a thing? Any answer, that a technological moron like me would comprehend, would be very much appreciated. | Technology | explainlikeimfive | {
"a_id": [
"g4j5b6l",
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"text": [
"Most of the time a bad guy has figured out a bug in windows that they can use to do bad things to a computer. Microsoft found a way to stop that, and they're changing Windows so it doesn't happen. (Security Update) Other times a problem other people had got fixed, and rather than having to ask everyone what everything is, they give everyone the fix. (Bugfix Update) Some times they add new things to Windows. You just might not be able to notice it, or you might not be using it. (Feature Update)",
"> Why Windows forces its users to update the software all the time? Because back when it was optional and voluntary, a whole lot of people didn't update, and Windows was more full of security holes than a swiss cheese. So in the end they decided \"screw it, we'll make it mandatory\" > It takes like an hour or two of my computer being completely useless when this happens. With every subsequent update I can notice my computer working considerably slower Sounds either very old, or very low end. What are your specs? > yet I do not see any changes whatsoever. The vast majority of updates fix small problems that you may not personally run into. Issues like \"when you do this very particular thing, this particular program crashes\". If you don't do that thing, or don't use that program, you're not going to notice the difference. Changes that are visibly very different are rare. > Why is that a thing? Because it's a bad practice to change a lot at once. If you're trying to improve your car, the smart way is to change one component at a time, and test after each, rather than installing 20 different mods all at once, then having to figure out which one is causing a problem. In the same way, Microsoft does small, incremental changes so that if something does go wrong they have a much easier time narrowing down the problem."
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ipd247 | When your phone recommends "smart replies" based off of what you typed in a message, does that mean that Google (or whatever company) is reading all your messages and mails? | Technology | explainlikeimfive | {
"a_id": [
"g4j6xz9",
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"text": [
"No, it's an algorithm (a bit like autocomplete) that remembers which words you often use in succession recommends them to you. Tinfoilhat=ON this doesn't mean that Google or whoever *doesn't* read your messages",
"Yes, and no. Think about spell check. Does that mean that someone is reading what you type? The program you are using is aware of the words you are typing, but it is not gathering information from your document beyond trying to figure out if you mean to type \"read\" or \"reed.\" Auto replies work the same way, but are contextually influenced. If you're replying to someone's \"Thanks!\" it's not hard for the program to suggest that the most likely response starting with \"y\" is going to be \"you're welcome,\" instead of \"yellow submarine.\" Some programs can learn and build a suggestive vocabulary based on your personal word usage, but no one is reading what you are typing.",
"Yes. It probably doesn't mean Google/Apple is reading your messages in realtime on a central server - rather, the messaging app has a bit of logic where it reads the last message locally, and goes \"I was told by my programmer that the most likely response is one of these three, so I will offer them up\". It's all happening locally on your phone, so it's not really a huge privacy/security issue.",
"Nowadays they can read it on device. So the algorithm can read and come up with replies locally. Doesn’t need to send back to central server. It’s becoming more common too as the phones get more and more powerful. For example, with iPhones you’ll notice when you change devices the autocorrect on new phone doesn’t remember your old patterns. It takes some time to relearn them. That’s cuz apple does autocorrect is on device only. Even if you backup/restore files from old to new phone it won’t bring across your autocorrect patterns. It will have to relearn them. Some find it nice cuz of privacy, some find it annoying that it has to take time to relearn."
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ipdh8t | How do credit cards work when they use the phone lines vs. someone using the embossing machine? When are things submitted? | Technology | explainlikeimfive | {
"a_id": [
"g4j9cbc"
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"text": [
"The credit card systems is using the same procedures as before but we have just automated it. So instead of humans doing the work we now have automated machines who do the same thing. A credit card terminal does the same thing as when people call the bank to verify a transaction. When you swipe the card the terminal will read the numbers of the magnetic stripe. It then calls the bank and sends over the card information and the details of the transaction. The bank may then challenge for a pin code that have to be entered by the cardholder. When the bank is confident that the transaction is legit it will confirm this with the terminal and they both log the transaction as completed. The money is then transfered after having completed lots of other verifications offline, some of which require that the banks wait for more information so it can take up to two months for the money to finally arrive. If you are using a chip and pin the process is slightly different. The chip in the card is actually a small computer and it does not hand over the card information as easily. Instead the terminal will send the transaction to the card who might then ask for the pin. It then creates a digital signature of the transaction and the terminal will go on to send the signature and the transaction to the bank for verification and logging like in the example before."
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ipef2r | Why do factory lights make that distinct "bum" noise when you turn them on/off? | Technology | explainlikeimfive | {
"a_id": [
"g4je706"
],
"text": [
"What you're hearing is the ballast that's regulating the current going into the lamp. Electrical ballasts use a magnetic field to manage the current going into the lamp- as the current would otherwise increase until the lamp was destroyed or a circuit breaker tripped. A side effect of this is a buzzing sound that can occur from the interaction of the magnetic field and the ballast's ferrite core. It's known as magnetostriction and can be more pronounced as the ballast ages."
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ipeq2i | What's the difference between a first party, second party and third party game developer/publisher? | Technology | explainlikeimfive | {
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"g4jfj4w",
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"text": [
"First party is the same company that manufactures the videogame console, such as Nintendo, Sony and Microsoft. Second party is a company that signed a contact with the console maker to develop games for that console, such as Game Freak (Pokemon) and Bungie (Halo). Third party is any other company which develops games for that console.",
"A first party game developer is the same company that manufactures the console. For instance, Mario Odyssey or Breath of the Wild for Nintendo. A second party game developer has a contract to explicitly make titles for that console. Think of it as a console maker contracting out their first-party game development. That company still gets to brand their games, and after their contract is up can ride on that reputation. A third party game developer is one with no official ties to any specific console. They can choose to develop for a single console or make a cross-platform game.",
"The term comes from contracts in general. A contract is between two parties. Usually the first party is the one who writes the first contract proposal and the second party is the one who signs it. A third party would be anyone who might be mentioned in the contract but not actually one of the signatories. The use of terms to describe the different parties instead of mentioning them by name is because a lot of contracts are first written as a template before anyone knows who the specific party is. It is then easier to just insert a line at the begining of the contact saying who is the first and second party of the contract as then you only have to ever change the first page of the template to reflect who the parties is. Quite ofte the third party is also unknown at the time the contract is signed so this is the most common term that might appear. In video game development the contact in question is usually between the developer and the publisher. The bigger of these parties is the ones who usually have the contract template as they have to sign contracts with lots of people. So publishers is usually the first party. The second party would then be the developer and any others who are mentioned in the contract is refered to as third party."
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iph2yj | why and how do oled screens burn ? | Technology | explainlikeimfive | {
"a_id": [
"g4jt5hw"
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"text": [
"OLED pixels produce light. Over time, the heat that's produced leads to reduced brightness. The \"burn in\" effect was named way back in the phosphor CRT days, when a completely different process was in play."
],
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7
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ipjn0x | Why can't my phone camera capture the moon, just the way i see it ? | Why are camera in able to capture the moon images, the way in which my eyes are seeing it? | Technology | explainlikeimfive | {
"a_id": [
"g4k8zxx",
"g4krqio"
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"text": [
"From my understanding of it. Your phone camera is set up to have decent quality for things like 10 to 50 feet in front of you, while capturing a bit of the surrounding areas. So with the moon being so far away it always looks tiny in pictures. Unless you get one of those super fancy DSLR cameras with basically a telescope in front of the lens, its always just going to look like a little bright ball on a bunch of black",
"In short - your eyes are better than you think, your phone camera is worse, and the moon is actually really tiny. If you hold your thumb out at arm's length, it can easily cover the moon. If you compare that to other things in your surroundings, it's like trying to photograph something like a spool of thread from across your living room. Your cell phone camera couldn't do a good job of that either, because it's designed mostly for photographing people at short distances and wide location shots. The moon often \\*seems\\* bigger though because our eyes are pretty awesome! We can make out very small details in things small and far away, and deal pretty easily with the brightness of the moon compared to the dark night sky."
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ipm3hb | What is actually happening within your computer when it freezes? | Technology | explainlikeimfive | {
"a_id": [
"g4klp2o"
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"text": [
"Everything in a computer boils down to bits (zeroes and ones) and simple math on those bits. Things like addition and substraction, or just storing a number and then retrieving it. All the complex stuff you do with a computer, boils down to thousands or even millions of those small operations. So when a computer freezes, it's because the computer is trying to do the math and it has so much to do, it stops updating the screen while it tries to do the math faster."
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ipvudf | What is inside an Etch-a-Sketch that allows it to draw when nobs are turned, but erase when it is shaken? | Technology | explainlikeimfive | {
"a_id": [
"g4me0ai"
],
"text": [
"Its a type of sand. When you move the knobs it cleans the sand off the screen. When you shake it you re-cover the clean parts of the screen and start a new drawing."
],
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5
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ipz38e | How so law enforcement officials and agencies trace the identities of those who circulate child pornography/ rape/ universally objectionable content especially on WhatsApp, given its end to end encryption? | Technology | explainlikeimfive | {
"a_id": [
"g4n0z7v"
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"text": [
"As far as I know in these cases, it's usually not a matter of breaking the encryption, it's a matter of compromising one of the endpoint devices. If you can install some spy code on the computer/phone *running* whatsapp, then the encryption doesn't matter. Sometimes law enforcement has the means, through a phone manufacturer or network provider, to get software pushed to a phone so that it can be monitored. And sometimes it can be installed by exploiting insecure software or hardware in the phone."
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iq0n9h | Why do two phones in the same room make weird sounds when on a live call? | Sometimes even if only one of the phones’ mic is on. | Technology | explainlikeimfive | {
"a_id": [
"g4nhnrr",
"g4ni5qa",
"g4nik0t"
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"text": [
"This is called feedback and is similar to what happens if you put live microphone near a speaker connected to it. Microphone on one phone picks up a sound, then the other phone plays that sound and the first phone picks it up again and amplifies it in an continuous loop ultimately causing a high pitched noise.",
"Feedback. The same soundsource is „heard“ and „played“ at the same time. The same issue occurs when the microphone is getting too close to the speaker. It’s a feedbackloop. The sound from the speakers go into the mic and come out of the speakers and go into the mic again...",
"The weird sounds are a result of feedback. When a sound is made nearby two phones that are on speaker, phone one is producing a sound (output) and its being received by the second phones input. The second phone then reproduces the sound through its output which is then received by the first phones input. The cycles continues in a feedback loop, as each output reproduced increases the amplitude of the signal. The signal is broken when the sound either is too quiet to be picked up by an input or if any part in the loop (input, output, input, output, etc.) is broken."
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iq19xk | What is a 'Flick' when it comes to movies? | Technology | explainlikeimfive | {
"a_id": [
"g4no0ys",
"g4o6bl6"
],
"text": [
"Flick is just another word for a movie. It comes from the word \"flicker\" because of how they look on the screen (it's a not consistent brightness lighting up the movie on the big screen, it changes rapidly)",
"* For decades movies were shown on film projectors. * These devices rapidly show a series of still images imprinted onto a film strip that is run through the projector. * For each frame of this film strip, the projector grabs the frame and holds it still for just a moment. * Then a shutter blocks the light while the frame is released and the next frame is moved into place. * Then the shutter is removed and the new frame creates a projection on the screen. * This constant blocking and unblocking of the light from the projector creates a flickering light, especially in the back of the theater where the projector is."
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iq1ftl | How is something digitally unduplicatable? | Not a programmer and don't have much knowledge of code but... In the physical world though there are ways of duplicating things, i.e moulds in a factory, but most things are unique and not easily duplicatable. In the digital world, I would presume it's the opposite, most things are easily 'duplicatable' because you can just copy and paste code. How are things in the digital world made 'unduplicatble?' Is it just a case of hiding the code? Therefore it is just difficult to duplicate not impossible. | Technology | explainlikeimfive | {
"a_id": [
"g4nrhoo",
"g4ntl7n"
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"text": [
"Basically yes. Code can easily be copied and pasted. That's why companies execute important code at their own servers (the backend) and not on the client side. And applications that run only on the computer (client), like photoshop have their code obfuscated and turned into an executable ( a binary file that only a computer can read). There are programms that try to reverse this process, but the code still won't be good to read. So you can't modify it easily and then they hide code to verify that the programm wasn't modified and has an active license, while on the other hand \"hackers\" try to bypass said functionality.",
"This is the problem with DRM and copy protection... How do you protect something against unauthorized duplication and tampering while at the same time giving it to the user in such as way that you can't control what they do with it? The answer is you can make it very difficult, but you can't make it impossible against a suitably motivated and skilled adversary. For example software can phone home via the internet to confirm the user bought it, but someone could simply edit the software to remove that check... you can check if the software has been tampered with, but that's still just more software that can be tampered with. You can issue an update that changes how copy protection works, but I can just not update and keep the old version. You can escalate this a long way, but it can't go on indefinitely."
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iq5fun | What is NVMe in Solid State Drives? | I tried reading the description on Tom's Hardware website, but I didn't understand what I was reading. | Technology | explainlikeimfive | {
"a_id": [
"g4p53eh",
"g4p84m2"
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"text": [
"It's an interface (special connector with a specific algorithm) that allows SSDs to access to it's data way faster than the older protocols used for the old hard drives and old SSDs. Quick summary on how: Old hard drives have a disk that rotates and a \"needle\" that reads a position of the disk in order to retrieve data (kinda like vinyls, yeah). This allows only to obtain 1 piece of data at the same time. SSDs are a bunch of chips that retrieve the memory position they are asked, with no moving parts, so the limitation of 1 piece of data at a time shouldn't exist. However, first SSDs are designed to be compatible with the old HDs and hence only support obtaining 1 data at a time, but faster than the HDs. NVMe just change that \"one piece data at a time\" to allow several search operations to be performed in parallel.",
"NVMe is a faster equivalent to SATA for connecting the drive to the system SATA was built for old HDDs which are relatively slow and can't respond to very many requests in a timely manner. NVMe was designed explicitly for SSDs, specifically those little ones that go in that narrow M.2 slot on the motherboard. NVMe using 4 PCIe 3.0 lanes will manage about 32 Gb/s while SATA 3 will manage just 6 Gb/s giving NVMe a peak throughput that's 5x higher, but real performance can be even higher. Old hard drives are ludicrously slow compared to the CPU taking millions of clock cycles so requests were punted out and checked on a couple eons later, but modern SSDs are only a couple orders of magnitude slower than RAM(tens of thousands of clock cycles) and it can read multiple blocks at the same time so NVMe increased the amount of different requested datablocks that can be queued up for the SSD since it can get to them in a timely manner, this means that more of the SSD is busy at any given moment so you lose less time waiting between reads. Having a 32 Gb/s bandwidth doesn't help if you spend 75% of your time waiting for the next thing to read so the deeper queue helps significantly."
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iq60vq | how does Sirius starlight provide on demand content | I can’t wrap my brain around how I can choose content and stream it to me with millions of customers at times doing the same thing. How does this work? TYpo in title Satellite not starlight.... ugh | Technology | explainlikeimfive | {
"a_id": [
"g4pa9c3"
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"text": [
"The Sirius On Demand library is only offered through the Sirus app on your mobile device. So its not using the Satellites. As for how that works, it works not much differently than Netflix, Amazon Prime, Spotify etc. If you have a landline or wireless data connection, it works. You may have Sirius On Demand in your car, but that's because your car receiver is using a wireless cell connection (like OnStar does). (rarely mentioned tho is that Sirius has ground based transmitters in urban areas to augment the two satellites that your receiver is listening to, in case of building interference etc., I thought that was neat)."
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iqa3ur | How do fans cool down the air that goes through them? | I get that spinning the propellers in a circle very fast would propel the air towards whatever the fan was pointed at, but how does making it move cool the air down? Especially when it's hot outside, shouldn't you just have hot air blowing in your face? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"It doesn't. It makes sweat on your skin evaporate, which cools you down. Water usually must change temperature or atmospheric pressure to change state from liquid to gas",
"It doesn't. In fact, the friction between the blades on the fan and the air actually heat up the air very very slightly. Fans don't do anything really except move air. If you have a room that is sitting at 80 degrees, and you have 100 fans in it blowing air all over the place, the room will never cool down if no external forces start introducing cold air. It will gradually heat up. However, if we as humans (and other animals) stand in front of the air that the fans are blowing, it will feel cooler to use, because it's moving past our skin faster. The more air that moves past our skin the more our skin can shed heat, so it makes us feel cooler. But fans do not cool down air at all.",
"Everyone is referring to the cooling effect a fan has on our skin via evaporation. But if you're asking how a fan can cool a PC for example, as others have said it doesnt actually cool the air it comes into contact with. It instead moves a portion of the air away to be replaced by a new volume of air. So when a PC's motherboard heats up air around it, the fan continuously moves new air into place."
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iqc33r | If computers can process millions of instructions why does it take a couple minutes for my laptop to boot? Are there really that many instructions to process? | Technology | explainlikeimfive | {
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"text": [
"> Are there really that many instructions to process? Yes. There is also times when the processor can't do anything because it is waiting for data from the just-spooling drives or the network port that is still negotiating with the upstream switch/router.",
"The problem likely is not the CPU, the problem is the hard drive. The instructions to boot and for the operating system to run have to come from somewhere and they come from the hard drive. And hard drives are slow unfortunately. It is likely spending much of that time waiting for the hard drive to give it the data it needs. This is why most newer computers come with something called an SSD, solid state storage. This uses different storage technology than a hard drive and is much faster. While it is a little more expensive, prices have gone down a lot in recent years. My computer boots in 5 or 6 seconds as a result of this.",
"It doesn't do processing of instructions all the time. To process anything it should be readed from the disk into memory. Disks are very slow as compared to processors. Also, one instruction is something pretty simple as basic arithmetic operations.",
"There is a whole set up process that occurs when you boot up. To use a crude analogy, you have to unpack the lumber, build the house, wire it, install the plumbing, move in the furniture —- and then you can move the people into the house. And if the people try to do things in the house before it is dine being built, it gets messy. There are a couple of different ways you can “build the house” as it were: you can build the entire house all at once, build the foundation, then the lumber, then the wiring and plumbing, etc etc etc. and then turn the house over once the entire house is done. Then there is another way: do the foundation first and then build the entire entry way before anything else - lumber, wring, lights. And let the people into the entryway. And then start building the living room next, release the living room to the people and move onto the kitchen. It gets minimum functionality quickly, but you don’t get the whole house any faster. Yes, this is a crude analogy."
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iqf7cv | What causes internet speeds in the same location to fluctuate while downloading something? | Technology | explainlikeimfive | {
"a_id": [
"g4rr6p2"
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"text": [
"Think of your internet connection as a highway. Think of data as the cars. The more cars you have trying to go down the same road at the same time will have variances in speed, maybe you got a clear opening on the left and that guys going super fast. Then you have someone taking their time on the right and someone slowing down for a passing cop lol. And they’re all going to the same place and they all have to put a big puzzle together at the end."
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iqhshs | How do computers interpret new programming software? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Because all software engineering packages ultimately compile the software down into code that the computers can understand. Think of it as an interpreter. You, as a developer, writes code in whatever language you know. The computer understands it's language. The programming software translates your code from the programming language to a language the computer understands."
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iqifen | how is internet speed different than internet bandwidth? | I recently upgraded my internet plan from 150Mbps to 1Gbps. After being dissapointed that my PC was only picking up 1/4 of the speed through wifi, I bought a long Ethernet cable and ran it through my living room into my bedroom. Now my PC is getting \~800Mbps upload and download. But I am still not getting very good ping when I play online games. My friend said its because my good speed doesn't mean I have good bandwidth. I googled it but I can't seem to find an easy to understand article about why I'm still lagging with such good speed. | Technology | explainlikeimfive | {
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"I'm currently learning this sort of stuff for my new job. From what I understand so far, its easiest to look at it as a roadway. Bandwidth would be like a highway, the more bandwidth you have(the wider your highway), the more data (cars) you can fit on it at once. Speed would be how long it takes for your data to get from the server/source to you. Please, anyone correct me if I'm wrong!",
"Now I'm not the best to explain this, but I'll give it a shot. Internet speed and ping are two completely different measurements. Think of speed like a highway, the more speed you have, the more lanes you put on the highway. Ping on the other hand is the amount of time it takes for your \"car\" to travel to your target server and back, hence why it's measured in (ms) milliseconds. For instance, I sadly have Satellite internet. What this means is that my \"car\" needs to travel 22,000 miles to a satellite, then 22,000 miles back down to earth... That's just half the trip as I still need the data to come back to me. This leads me to ping between 700 milliseconds and 1600 milliseconds. If you don't have satellite internet then I'd highly recommend learning how to ping a server and seeing if your \"car\" is taking a roundabout way to its destination, which can be common with certain ISP. If it is, switching to another server or I think using a vpn can fix this but am unsure as I've never had this problem."
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iqiu6b | Advantage of medical experiments conducted on ISS | So I know that the ISS has made a lot of contributions to the field of medicine and pharmaceuticals.What I want to know is that how and why does microgravity play a role in this field as I guess it's the only variable that's changed by testing it in space; everything else can more or less be simulated on earth. | Technology | explainlikeimfive | {
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"Things get weird in microgravity. We can do some experiments in microgravity if they’re less than a few minutes long. But if someone wanted to see how a biological process worked for more than 10 minutes without gravity, they’d need the ISS. Sometimes, they’ll find that microgravity has no effect, other experiments find that it does affect the results. Why will vary based on the specific experiment. For example, a few diseases are much more virulent in space because the microgravity makes them want to reproduce faster than they usually do.",
"Microgravity can also influence sedimentation behavior. On earth, dense things sink. In space, they don't. That means if you have a biological process that creates some product, there's no natural method for pushing it away. Hot air doesn't rise, and cool water doesn't sink. If you put algae suspended in water and let it create oxygen, it'll just create a bubble around it. The bubble won't float to the surface. I'm part of a project working on developing watering systems for plants. On earth, water flows down in the soil because of gravity. Roots can hunt down and find the depth with just the right amount of water for them. In space, the water wants to blob up (its flow is controlled by surface tension), and you don't get that nice smooth transition in the soil from wet to dry. You get soaked or dry."
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iqix2i | why does google chrome use a lot of RAM? | Technology | explainlikeimfive | {
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"Chrome splits each tab and extension into its own process, so if one thing crashes it won't bring down your entire browser. The trade off is extreme RAM inefficiency."
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iqoier | How does fps work? Does it interpolate between frames? | More precisely in animation. Like there’s the same number of still images, yet increasing the fps rate somehow makes the animation more smooth. | Technology | explainlikeimfive | {
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"Modern tools that increase FPS in preexisting videos and animations use neural networks to interpolate between frames, essentially drawing additional images based on the existing ones.",
"Well if it was the same number of still images and you increased the fps, it would make the video faster. You would need more frames along with higher fps to have the right timing to get the video to look smoother.",
"Well, most of the time. Generally there are three major \"methods\" 1. There aren't the same number of frames. If you double the framerate the artist will draw twice as many images so that the animation gets smoother. 60fps? Well, someone literally drew 60 images for every frame of the action. This, as you might expect, is quite labor intensive. 2. You're correct: the system will interpolate between frames. Generally what happens is that the artist will draw/animate a few special poses called \"key frames\" which define major points of the animation, and define some parameters like speed or timing. The system doing the drawing will then take those keyframes and settings and for every frame \"in between\" where it doesn't have a keyframe it will draw an \"in-between\" frame where the animated thing will transition from the last keyframe to the next. This is much easier and cost effective, but can seem stiff if the parameters are incorrect. 3. They simply play some frames twice so that while the framerate is \"double\" the animation is effectively playing at the exact same speed.",
"In 1878, there was an argument about whether or not a horse lifted all of its feet off the ground when it was running. Some said no, that it always had at least one foot on the ground, that it had to have at least one foot off the ground, while others said it momentarily lift all four up as it ran. To settle this, they set up a series of cameras on a race track, and ran a string across the track. As the horse moved passed the camera, it broke the string which triggered the camera. They created a series of images, proving once and for all that a horse does, indeed, lift all four feet off the ground. In studying the images produced, Eadweard Muybridge created his zoopraxiscope, a disk that had all the images upon it, that when spun up, created an animation effect - just a few images/second tricking the eye into seeing a horse in motion. It had just a few frames -- each a different picture of the horse in motion -- passing by the eye at a set rate: frames per second. [ URL_1 ]( URL_1 ) [ URL_0 ]( URL_0 ) & #x200B; #"
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iqppk3 | Why does turning something off and on again seem to fix so many tech problems? | Technology | explainlikeimfive | {
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"Maybe a true ELI5: Imagine the computer being thousands of little workers. When the computer starts, all workers go to their starting position, where they have their tools and their instructions. Then they start working and moving around. Now while working one of them looses it's instructions. One of them looses it's tools. Now imagine that happening to a bunch of workers who work at the same spot, say the graphics card. And also they don't know who to speak to about that. So they basicly wander around being lost. Turning the pc off and on again now makes all workers return to their starting position where they get their instructions and their needed tools again. And now they can properly go to work again. Grossly simplified and probably not the best metaphors but here you go, an eli5 explanation.",
"It is very hard to troubleshoot and bug fix weird problems that occur after many hours of uptime and many hours of random events occurring, especially on home consumer devices. However, turning the system off clears any weird values in memory that were causing these errors and returns you to a clean state, where the large majority of testing was done from."
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iqraua | Is it actually dangerous to unplug a hard drive without "safely removing hardware"? | I understand there could be background processes that are happening, but there are definitely times where things don't seem to be happening at all (even when you use a program to detect which processes are running) and a hard drive will still say "it's in use". Can physically unplugging the drive really destroy the drive? | Technology | explainlikeimfive | {
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"It doesn’t cause any physical damage to the drive itself, but if a program is saving a file to the drive and you unplug it it cannot save the file and you lose the data, and if you do it while the operating system is saving the file allocation table, you can lose everything, the files are still recoverable, but the operating system cannot read the data form the drive, this actually happened to me one time",
"If you move a magnetic hard drive during operation you can cause the heads to hit the spinning plates inside, physically destroying it. But that's usually not what safe removal is for. Hard drives have a small volatile cache that will be lost when it's unpowered, any data just present in that cache that has not been written will be lost. The drive could also be in the progress of writing a longer sequence of data that will be left incomplete, corrupting either the file or the whole file system, making your data unreadable until restored.",
"A mechanical hard drive operates by having a read/write head on the end of a mechanical arm skimming across the surface of the platters of one or more rotating disks. Those heads are kept from hitting the surface by the air dragged along with the platter by its rotation, skimming just a few nanometers above. At that distance they could collide with an obstacle as small as a fingerprint or a single particle of smoke. If you unplug the drive while in use it cuts power to the drive while the heads are out on the platters. In the milliseconds before electrical charge fully fades from the circuits the drive must move the arms and heads to safely park them before they crash into the surface of the disk rotating at thousands of revolutions per second, damaging or destroying themselves and data in the process. Maybe it can do it, maybe not. Going through the proper removal process will prevent that emergency."
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iqs6kq | How exactly does a computer make sense of binary (1s and 0s)? | Technology | explainlikeimfive | {
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"Binary is just a representation of voltages on circuits. Those circuits do basic binary arithmetic (AND, OR, NOT, NAND, NOR, XOR), and produce new voltages out the other end accordingly. You line up a lot of those and it looks like you've taught a rock to think using electricity. Binary is just how we represent whether we're putting positive voltage on the line or not."
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iquiso | Why is it that you can keep a house phone on it's charging dock for years and it doesn't destroy the battery where as a cellphone will eventually wither over just a couple years if you charge it for too long everyday? | Technology | explainlikeimfive | {
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"It's not the continuous charging that damages modern cellphones. Modern smart phones have smart charging causing them to switch to a trickle charge that keeps the battery topped off without over charging. There is some truth that keeping a cellphones batter near 100% often will damage the cells, but it's not because of overcharging. The reason cellphone batteries weaken overtime is just wear and tear at the atomic level. Overtime as the battery charges and discharges the materials inside get worn and degrade and just don't work as well so they drain faster. Things that accelerate this wearing of cells are things like: * Letting the lithium battery fully drain before charging * Constantly charging to 100% * Excess heat builup * Freezing cold temperatures. The above puts extra strain on the cells and makes them degrade faster. If you avoid these things the cells will still degrade from everyday charging, but not nearly as fast. You also have to consider the phone is doing more work overtime as things update. As software/apps update they become more power/resource hungry. Your phone is going to drain the battery faster as it uses more processing power to handle the new software giving the illusion that your battery is going bad. Same idea as your computer is slowing down after a couple of years. It's the same speed, the games are just more demanding. Comparing this to a portable house phone isn't really accurate. Your house phone most likely has the same problem with a worn out battery, You just don't use it for hours on end. If you have an old portable phone it may very well only last 10 minutes these days where when it was new it would last hours.",
"Edit: ELI5 version. The batteries are different types on the inside. The cell phone type gets hurt at 100% charge and the cordless house phone type lasts longer at 100%, plus the house phone type is much cheaper and easier to replace (so even if it doesn’t last super long, it’s not a big deal). Edit2: ELI20 now features more ELI20-like-explanations In parentheses. I've worked in the battery biz for 10 years. Most commercial li-ion batteries don't handle high state of charge (battery % shown on your device) very well as the oxidation rate (how fast the liquid inside is getting used up) of the electrolyte is high at this state, so you lose lithium ions rapidly (battery can’t store as much charge.) This causes loss of capacity (runtime). The internal resistance (resistance is the phenomenon that reduces battery power) of the battery goes up at the same time, and it can't charge/discharge as quickly anymore, so the end effect is it can't perform well in the device (the device needs a certain amount of power, which the battery will eventually struggle to deliver) and this actually accelerates the capacity fade even more. (Battery loss of runtime will get worse each day) Most household phones are Ni-MH chemistry which is much lower energy density (heavier and less sexy) but handles high state of charge much better. They used to put Ni-MH in cell phones in the mid-to-late 90s, they were big, bulky, and didn't have a lot of talk time. Li-ion was better in every way for cell phones. For household phones this isn't really a problem, and Ni-MH is much cheaper to implement, plus they are more easily customer replaceable (they don’t catch on fire, and are widely available) You can get a much longer lifetime out of lithium-ion batteries by implementing lower maximum voltage, for example 4.1V max charging voltage instead of 4.2V. This is called derating and is used in more high-end applications like Teslas (4.1V is normal charging mode, 4.2V is \"extended range\" mode which you shouldn't use if you don't have to). \"Regular\" lithium-ion batteries are usually charged to 4.2V and the device makers don't give a shit about the long term longevity, they just want to advertise longer runtime on a single charge at beginning of life.",
"When a battery is fully charged the power doesn't go to the battery it just skips it and makes sure it just retains its full charge and only rarely uses its battery. A cellphone/mobile phone constantly drains and recharges. This constant discharge and recharge is what damages batteries. If you kept your cellphone on charge 24/7 it would be the same as the house phone. Additional: while batteries do degrade over time when on charge continously, trickle charging reduces battery performance by a very negligible amount that you wouldn't notice it over a 12-18 month period at all upon taking it off charge plus if its always on charge its not like it matters. There are external factors which will impact the performance more than trickle charging such as heat.",
"In addition to the other answer about not constantly discharging it, the chances are that you rarely use the house phone for an extended period of time. If the battery can last a few hours when the phone is new, even if it loses half its capacity over a couple of years, you'll never notice the decrease if you only use it for 10-20 minutes at a time.",
"I think there are three effects at play here: 1. You don’t really notice that your cordless house phone’s battery only has 40% of the capacity it started with. 1. Keeping a battery charged is not really damaging. They do age over time and at least for Li-Ion batteries apparently it’s best to store them at ~60% and relatively cool temperatures. But simply being plugged in and kept at 100% isn’t really bad. 1. Deep discharge is harmful for most rechargable batteries. You probably only discharge your house phone by a few percent, then immediately charge it again. 1. Cell phone manufacturers try to put as much charge as possible into the battery. This means charging to high voltages and discharging to very low voltages. They are also charged much more quickly and get hot a lot more. This is bad for battery life. A properly cooled and carefully charged battery (like in electric vehicles) will live longer.",
"When I had home cordless phones with batteries, I’d have to change the batteries every couple years on those, too, or else they’d only have a few minutes of talk time.",
"> a cellphone will eventually wither over just a couple years if you charge it for too long everyday? I think you began with a misconception. Your phone's battery does not become weaker over time if you charge it too often. In fact quite the opposite, if you don't charge it enough, areas of the cell can crystallize and stop acting as battery capacity. URL_0",
"House phone batteries are low amps, low voltage, and very simple. They don't need to run a fairly powerful CPU, Memory and huge, bright touchscreen, 4G internet transmitter/receiver, and all the other gadgets in a smartphone. So the batteries are much less powerful and complex, and the phone itself can tolerate a greater loss in performance from the battery before it's noticable. Ontop of that, cellphones batteries are almost or completely discharged regularly, which is the main cause of battery life decreasing. Home phone batteries are very rarely completely discharged, or even go below 75%",
"I came here thinking that the OP was talking about corded house phones which do not have a battery and are powered by the low voltage of the telephone line; totally forgot about cordless phones. We had to change the batteries on the cordless phones every so often as well, this usually meant a trip to the local Radio Shack with the battery in hand to get the right one. Every now and then the replacement battery was just as much as a new cordless phone which we would return with a new home phone and spend the next few hours programming in the auto-dials, which would also result in an argument as to which family member was in which position on the auto-dial.",
"It doesn't, and the supposed \"battery expert\" currently at top comment is regurgitating shit that hasn't been true since 2005. You're not \"charging it too long\" it's just normal wear and tear.",
"I watched a video from an MIT professor and he said keeping it 100 all the time is probably the best. Batteries don't display it's real charge. They don't ever go to 0% nor do they go to 100% it's a non linear graph. When you charge closer to full, the voltage and amp goes down slowing the rate of charging. Charging from 0 to 100 is different and more damaging to the battery than charging from 60 to 90 a few times. It is also in relation to the temperature of the battery. Short charging time equals small increase in temperature. I always charged my old phone in short cycles for over 3 yrs and it never had battery issues. I do the same with my current phone as well. Some people still think you have to let it go all the way to 0 before charging. That's bad because you have to wait longer for the phone and does more damage to the battery.",
"My experience with wireless house phones is contrary to your very premise. All batteries decay.",
"What you're describing isn't a thing. Hasn't been for decades actually, it doesn't apply to li-ion",
"I love how all the explanations skip right over the question. What's the difference between old cordless phone batteries that last for more years than cell phone batteries?",
"House phone = Nimh battery Cell phone = Lithium Ion Two different chemistries. LI ion holds more energy but is less stable. NiMh holds less energy but is more forgiving and stable."
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iqxss9 | why do most 1080p+ HD webcams/nanny cams look terrible, but a DSLR streaming at 720p or less looks amazing by comparison? | Technology | explainlikeimfive | {
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"Dslrs have much better lenses and sensors than webcams. Resolution (also megapixels for phones) doesn't matter too much past a certain point.",
"It isn’t about the pixel resolution. It’s about the lens. A webcam lens is the size of a fingernail. A dslr lens is the size of a cup of coffee. The larger lens allows for a more professional looking depth of field, not to mention that the camera will have more control and capability for exposure, focus, aperture, iso, etc. Basically, pixel resolution is actually not a big factor in whether something looks pro."
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ir1p1r | Why is the default position for a 3-D model a T pose? | Technology | explainlikeimfive | {
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"It tends to make things easier when animating. For example, if a model's default pose was just A Normal Person Standing With Their Arms At Their Sides, the animators would have trouble making that model lift their arms without the armpits looking janky and weird. Putting the model into a T-pose makes the shoulders, some of the most maneuverable joints on the human body, easier to animate no matter which direction the arms need to go. It's also part of why the legs tend to just Be There. Most of the time, the legs just need to walk. They don't go doing the splits for every day-to-day activity, so they don't need to get splayed out like the arms do."
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ir5610 | How do they take the bones out of chicken and other boneless meat? | Technology | explainlikeimfive | {
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"They use knives, to make boneless chicken thighs or the like. When something is marketed as \"boneless\", they are marketing the work the butcher did, not the source product the butcher worked on.",
"Boneless chicken wings are just pre dipped chicken nuggets. The rest are achieved through knife work. Wings can be deboned but require a lot of skill. There is a chinese recipe where all but the bones in the tips are removed, and then stuffed with fried rice and deep fried."
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ir6dw5 | How do computer bugs affect two people with the exact same set up differently? | My brother and I almost always have the same tech. Whenever we play games together there are times when one of our game HUDs would disappear or our character would stop moving all of a sudden. | Technology | explainlikeimfive | {
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"Bugs can pop up as a result of specific actions you take in the game, and sometimes random things that happen outside your control. Even though you have the same tech, you aren't taking exactly the same actions at all times, so you can get different results."
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ir7v5f | how do pictures and stills from video have motion blur if it’s capturing one isolated moment in time? | Technology | explainlikeimfive | {
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"It’s not actually capturing a moment in time. It’s taking in light just long enough to see the image then closing the shutter again. For example the darker it is the more light it take to capture a picture and the easier it is to blur an image. The brighter it is the easier it is to avoid blur."
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ira3wm | When you type in an incorrect password, and you want to reset it, why does it say that your new password cannot be your old password? | Basiccaly, this scenario happens quite often. When I type in my password, it is incorrect. However, when I try to reset it, they say that my new password cannot be my old password. Does anyone know why this happens? | Technology | explainlikeimfive | {
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"It could be a few different things, 1)could be that you cant use any old password so your using an older password. 2) this is common one for me, your typing it incorrectly on the 1st screen. When your setting a new password you get to see the rules. 1 capital letter,1 symbol,no spaces and 2 numbers So when you can see the rules you know what password you would normally use to meet those requirements"
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irbn4h | What's the difference between a $350 DSLR camera with 24 megapixels and my $250 phone with 48 megapixels. | Technology | explainlikeimfive | {
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"Megapixel is not a measure of quality, it just measures resolution, sure low resolution looks bad, but anything above 2 MP can look great, it just depends on the camera. Just adding more pixels doesn’t make the image look better, really anything above 12 MP or so doesn’t really matter for cell phone cameras, since the lens and sensor aren’t really large enough to capture enough detail, the pixels are smaller than the maximum resolution of the optics. A DSLR has a much larger sensor and higher quality optics that really make a large difference to image quality, and 24 MP is plenty enough resolution",
"There are three main physical factors affecting image quality. Lens size, sensor size and pixel count. Generally these should scale up together. A high megapixel count without a meaningful increase in the sensor size just means your pixels are smaller. Smaller pixels mean the sensor sensitivity suffers. Think how much light (photons) a square inch gets vs a quarter inch now divide that by the pixel count. Also at the very high resolutions you run into the limitations of the resolution of visible light itself."
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ircvv6 | How do electronic devices accurately keep track of how much time has passed while it is completely powered off, without access to an internet connection? When they power back on, the date/time is told accurately, as if the device was never turned off. | Especially things like smartphones that aren't connected to the internet when they power back on after being depleted for a long while | Technology | explainlikeimfive | {
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"It is because you never turn them off completely. Motherboards, for example, have small button-shape rechargeable battery, which holds time even if computer's power cord is disconnected.",
"So the way that devices in general keep track of time is using a \"clock\" within the device. This \"clock\" doesn't work the same way that a mechanical clock does, it keep tracks of time by counting the number of pulses out of a component known as a \"crystal oscillator\". The device knows exactly what frequency the crystal pulses at, so by counting the pulses out it is able to precisely tell the amount of time that has passed. When your phone or device dies, it doesn't *completely* die, it just reaches a predetermined setpoint that will shut down basic operation of the device. The remaining battery charge will be used (simplified) to keep track of time and volatile memory. This is also why there is an internal battery in game cartridges that allow you to save your progress."
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irfd65 | Why can't 911 operators increase the volume of an emergency call to hear the victim better? | I dip into true crime every now and then and it always made me wonder why 911 operators can't just boost the volume on their end instead of asking a victim to speak louder especially in situations where the suspect is beside or near them or they are hiding. The amount of time wasted on asking the victim to speak up or "hold on I can't hear you... can you repeat that"x4 as they are bleeding or whatever seems not insignificant. Is the technology not there yet? | Technology | explainlikeimfive | {
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"There is a difference between someone speaking too quietly, and someone speaking unclearly. In 99% of cases it's going to be the second one. Phones are notoriously unclear and fuzzy sounding, and when you speak quietly you are easily overpowered by ambient noise. Increasing the volume will not help in those cirumstances, you will just get a louder jumbled mess. When they say to speak louder they are asking you to overpower the ambient noise and poor quality of the line so they can understand you, not purely a volume problem."
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irff54 | How do scientists know the composition of a planet? | I have always read that the core of the earth is white-hot magma, but at the same time nobody has reached a fraction of that distance. | Technology | explainlikeimfive | {
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"g4xz3d5",
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"text": [
"Radiowaves and other kinds of detective System that go through solid objects. Each object has a different pattern and waves go through them differently. So knowing how a wave acts on each type of solid or liquid, they know what the wave went throu and now they know whats under the earth's crust.",
"You know Pink Floyd's Dark Side Of The Moon cover? It's a prism that breaks up the light that passes through it. If you use a more precise instrument to break up sunlight you will notice the light spectrum is in fact not complete, there's an absence of certain wavelengths (-colors). This is caused by gaseous elements in the sun's atmosphere that absorb those wavelengths (thus those wavelengths will not be included in the light that is emitted by the sun). Every element will absorb unique wavelengths so by breaking up the emitted light and looking at the missing wavelengths it is possible to determine the composition of the light source. Edit: The core of the earth is a different story of course"
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irgpa2 | Why do some devices need batteries to be placed facing the opposite way but others have batteries both facing the same way | Technology | explainlikeimfive | {
"a_id": [
"g4y9cy3"
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"text": [
"Generally it's a matter of wiring. If you wire two batteries in series (+ of one battery connects to the - of the next) then the voltage that is provided across the ends of that chain is the sum of the voltages of the individual batteries. Normally that's the batteries placed the opposite way, or multiple batteries the same way in a line (like a flashlight that takes 4 \"D\" batteries. Batteries facing the same way is usually an indication of them being wired in parallel (all of the + are connected together, as are all of the negatives). That provides the same voltage as one battery, but for a much longer time. Of course, you can combine the two in all sorts of ways to get the specific voltage and battery life that's needed for a given situation."
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iri02h | Stealth technology on planes (or any other vehicle) | How does stealth on planes work? I assume it's some sort of design that doesn't reflect radio waves, defeating radar? Are there submarines that can stealth past sonar? | Technology | explainlikeimfive | {
"a_id": [
"g4yjwi1"
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"text": [
"A radar functions by emitting radar waves and then detecting those waves as they are returned by objects reflecting them back. You can design an object in a manner that minimizes the amount of radar waves that are reflected back toward the radar, making the object difficult to detect. There are certain shapes and certain objects that are particularly good at reflecting waves back to the radar, like spheres, curves, and spinning engine blades, and so by hiding or eliminating objects like those you can drastically cut down on the waves reflected back toward the emitter. You can defend against sonar in a similar way, yes, but nothing is perfect and simply minimizes your reflection, it doesn't eliminate it."
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irmbu8 | How does your GPU turn binary into visual output? | Technology | explainlikeimfive | {
"a_id": [
"g4zxq30",
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"text": [
"It's the screen, actually. The computer screen has a memory array that matches the dimensions of the pixels of color, and matches the \"brightness\" of each pixel based on the value in the memory location for that pixel. 60 or 90 times per second. The video card just does [matrix]( URL_0 ) math to calculate and upload to the screen the (red, green, blue) brigthness levels that each pixel should have.",
"I’m sure you’ve also heard of RGB. And I’m sure you also know that that stands for Red, Green, and Blue, because screens can mix those colors in varying ratios to look like other colors. Your GPU isn’t generating any visual output. What it’s doing is telling your screen how much red, green, and blue each pixel should have at a particular moment. Now let’s talk about binary. Binary is just a number system. While we typically work with numbers in what’s called “base 10”, binary is in “base 2.” In base 10, we have 10 numerical digits (0-9). In base 2, there are only 2 numerical digits (1 and 0). So the binary that your GPU sends to your screen is a set of numbers, and those numbers indicate exactly how much red, green, and blue a particular pixel needs at a particular point in time."
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irpfly | How does Spotify codes work if the design is so simple? | If you don’t know what I’m talking about it’s this [here]( URL_0 ) People can draw them on paper and they still work. They seem to work well and are very simplistic. And there are over 50 millions songs on Spotify, and infinite playlists. How does this work? | Technology | explainlikeimfive | {
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"g50vjhm",
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"There are over 20 lines of varying sizes in one of those. You can arrange 20 things in over 2 quintillion ways (2 followed by 18 zeroes). Spotify has a long way to go before they run out of codes. If they do, they can just add another line in the code, and now they have 3 more quintillion codes. Edit: yes I was too lazy to count the actual number of lines.",
"There are 23 bars, that can have 8 different sizes. The first and last bar are always the smallest size, and the middle bar is always the largest size (this is done for calibration). That leaves 20 'information' bars with 8 possibilities each, which can have 8\\^20 unique combinations."
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irqsco | Why are there suddenly so many prepaid phone services, such as Yahoo and Mint to name a couple? | Technology | explainlikeimfive | {
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"text": [
"You know major retail chains, auto manufacturers and even airlines started offering their own branded Visa or MasterCard? They did so to spread brand awareness and get a piece of the credit card revenue. All these prepaid cells are kinda of the same thing. They are buying access to cell networks and cell minutes in bulk contracts at prices you or I could never get. They then make their own line of cellphones and plans for what ever the going rate in your area is. It's not really all that new of a thing. My first cellphone I owned was a MuchMusic branded flip phone. (90s) I think that the reason you're seeing an increase is because the market for cellphones is pretty saturated and there isn't much to really make one carrier or line of phones stand out. So the cell companies do these deals with Yahoo and so on because there still some room in the niche market for branded stuff. Some people are more brand motivated than others, so a Yahoo! plan might appeal to some people."
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irqyyg | Why can only one person talk on a walkie-talkie channel at a time? | Technology | explainlikeimfive | {
"a_id": [
"g51l2bc"
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"text": [
"Radios can't receive and transmit on the same frequency (channel) at the same time; their own transmission drowns out the weak signal from a distant transmitter. If you need handle messages in both directions at once then you can use two different channels, but even then it's difficult to receive while transmitting because the local transmission is so much more powerful than the received signal that it can swamp the tuning circuits. Another approach is to use just one channel but switch rapidly between sending and receiving. Walkie-talkies are traditionally simple devices where having one person talk at a time is much less of a problem than going to the trouble and expense of enabling two-way talking. Modern digital communication technology is changing this."
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irr2ek | how does doxxing work? | I don't really understand how normal everyday people get doxxed, could I get doxxed? ( plz dont) or you? I don't get how whoever you are, the entire world knows and hates you in 24hrs ( in no way do I want anyone to be or do I endorse this, just no clue how it works) | Technology | explainlikeimfive | {
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"g51a3g2",
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"text": [
"Doxxing is basically revealing somebody's private address to the internet. Oftentimes it matters in cases where if you're a famous movie star or musician or someone that has pissed off the internet.",
"People recognize backgrounds, landmarks, signs. Someone found a famous YouTube address based on what they had in their back yard. One of my coworkers made a post about his truck. I recognized the mound of dirt in the background. So he was in the same area as me. I showed my supervisor and they recognized the guys pattern of speech. So in a subreddit with over 1 million members I identified a guy in 30 minutes from one picture.",
"Mistakes with revealing information. Let's go through a scenario. You use the same username across most sites you use. In school, you signed up for a competition, representing your school using this username. This gives me your name, high school and graduation date. I call or access the school's website and find out your last name. From here I use yellow pages or something else to find your phone number and where you live. Alternatively, I trawl your social media and you have a picture outside your house. I use Google maps to find out your general address, and use this to access house records, thus finding your name and phone number. Both of these were simply because you made a small mistake on revealing some information. Change your usernames among media sites, post as little information about yourself as possible on these sites and keep your profiles private"
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irsp4g | What are the mechanics behind needing to reset a modem when there's a slow connection? | Technology | explainlikeimfive | {
"a_id": [
"g53j0pt"
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"text": [
"A modem is just a specialized computer, and like all computers, a modem runs software in order to do its job. Software is really complicated as there are many different scenarios that need to be accounted for in order for a program to do its job correctly. When a specific scenario is not accounted for, there is no telling what happen, but sometimes, the program will keep running, but a part of the application starts malfunctioning. When we turn the modem off then back on, we reset all the parts of the application back to how they were before these software was malfunctioning"
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irt3gw | The difference between Information Technology and Information Systems | Technology | explainlikeimfive | {
"a_id": [
"g52fxf4",
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"text": [
"There's a large overlap between them, but in general: * Information Systems has a business / management perspective (not purely tech). Examples: business systems analysis (BSA); IT project & people management; management information systems; IT finance, etc. * Information Technology is heavy on the technical side. Examples: server administration; database administration; IT security, etc.",
"Information Technology is a subset of Information Systems. An information system is *any* system that is designed and built to organize and process information. For example, the card catalog and dewey decimal system used in a library is an information system. Information Technology deals with the technology of information systems. More specifically, the computer-based technology involved in designing and implementing information systems."
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irta5q | Why is the internet's upload speed usually a lot slower than the download speed? | Technology | explainlikeimfive | {
"a_id": [
"g52ato1",
"g52eos4"
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"text": [
"With adsl type connection. There is a limit in bandwidth so you prioritize download since that is what most user use internet for. Later on it was used to prevent people from running upload servers since they were a big expense for ISP. Fiber connections today don’t have a bandwidth limitation and people don’t run servers at home anymore so most fiber isp run same download / upload.",
"For some types of communication technologies there are technical limitations that cause your connection to be asymmetric (meaning upload and download speeds are different). The cable communications infrastructure uses some analog transmission technology that by its nature only has a limited band of relatively low frequencies for transmitting return signals. This is not an issue at all for normal television broadcast, which is what the technology was used for long before broadband internet was a thing. However, this limited return signal means that there simply isn't as much room on the line for your uploaded data as there is for your downloaded data. Therefore, your upload is slower than your download. Now, many technologies eliminate this issue. For example, fiber optic internet connections can easily be symmetrical (same upload and download speed). In these cases, your home internet connection is asymmetric because residential connections are considered \"consumers\". Meaning you go to websites and stream videos and do mostly things that involve receiving data to your house, not sending data from your house. Meanwhile, commercial internet connections can be classified as \"producers\" and they might have an internet connection that is asymmetric, but with faster upload than download. They will send much more data to users than they receive from users. By setting up connections to these consumers and producers asymmetrically, the ISP can allocate more bandwidth where it's useful instead of to connections where it may go unused most of the time."
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irtdj4 | I read a comment about a dude that said if you need more computing power SSH into your colleges server how would that work, and what does SSH mean? | Technology | explainlikeimfive | {
"a_id": [
"g52blur",
"g527sdf"
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"text": [
"SSH stands for Secure SHell. A \"shell\" is a program that allows you to issue commands to a computer. SSH is a program that allows you to connect to a remote computer and issue commands to it instead of the computer you're sitting in front of. Whether or not it would provide you with any more useful computing power is pretty questionable. Depends a lot on what exactly you're trying to do. Also, one would hope that you can't just trivially SSH into a random server being run by a college. If you can, I'd have serious questions for their IT staff.",
"It's just a way to log into another computer and run a program on it. You'd need a username, password and the name of it to be able to log into it over the network. Often college / universities have powerful computers that are accessible to those doing computer related subjects so they can run their programming assignments."
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irwdbf | How does encryption work? | Technology | explainlikeimfive | {
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"text": [
"The idea behind encryption is to scramble the plaintext in a secret way, such that only someone who knows the secret can descramble it. For example, one of the most classic and simple encryptions is [Caeser cipher]( URL_0 ), supposedly used by Julius Caeser himself. The idea is to take every letter in the text and shift it several positions in the alphabet, for example 'a' becomes 'd', 'b' becomes 'e', 'c' becomes f, etc. (and the shift is cyclic, so 'x' becomes 'a' and 'y' becomes 'b'). So for example \"hello\" is encrypted as \"khoor\". Decrypting is simply a matter of shifting the letters back. Of course, this method is pretty weak. Once you know it's a ceaser cipher, you just have to guess the shift (from 1 to 25). A little more complicated encryption is a simple [substitution cipher]( URL_1 ), where each letter is mapped to a different letter (or symbol). Decryption is just putting the ciphertext through the reverse map. The secret is the substitution table. From there the methods just get more complicated... If you're really interested about encryption and its history, I greatly suggest reading The Code Book by Simon Singh."
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"https://en.wikipedia.org/wiki/Caesar_cipher",
"https://en.wikipedia.org/wiki/Substitution_cipher"
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irwy6o | What's the difference between megapixels and video resolution? | I heard the Surface duo having an 11 megapixel camera, but able to record 4K, whereas I have a camera that's 20 meagpixels but only 720p, and the camera on my phone is 13 megapixels and 1080p. Can you please tell me why? Does it have to do with sensor size? & #x200B; Thank you in advance. | Technology | explainlikeimfive | {
"a_id": [
"g53fg47",
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"text": [
"Videos require a lot more resources than taking a simple photo. The camera's processor needs to process 30 or 60 images per second, compress them and save them to the memory card. Therefore cameras can usually take only videos with a smaller resolutions than the photos they can take.",
"Pictures are just lots of little coloured dots, each of those dots is called a pixel. If you have 4000 pixels in height, and 5000 pixels in width then you have 20,000,000 pixels, or 20 mega (million) pixels. Videos are like lots and lots of photos stitched together. 30 frames per second is 30 photos per second. If you’ve ever looked at the file size of one of your pictures, it’s pretty big. To take, and process, and stitch together and then store 30 (or 60 if in slow mo, or 120 if you’ve got super slow mo, takes a lot of processing so while some phones can take big photos with lots of pixels, they can’t keep up when doing video at that rate so they do smaller size. When movies say 720p or 1080p or 4k they are talking about the number of pixels in height. More pixels generally (but not always) means more detail / better picture but just because the sensor can take that many, doesn't always mean the phone can keep up with processing them all."
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irxlnb | how does active noise cancellation works and is it more harmful to your ears than normal headphones or earphones | Technology | explainlikeimfive | {
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"text": [
"Sounds are moving air. Active cancelation uses a microphone to listen to the sound, and then make an \"opposite\" sound by pushing air in the other direction. These opposite sounds are added to the music coming through the headphones. By the time it gets to your ear, the combined air from the original (ambient) sound and the opposite sound created by the device cancel out (mostly), so you hear more of your music with less outside noise. The music quality is a bit less because the music has extra sound added on top, but there's no more danger to your ears than listening to regular music.",
"No, it's not harmful. Noise cancelling headphones just play a tone that cancels out the noise around you. How does it work? Picture a sound wave, with peaks and valleys, coming out of a speaker. Now add a second speaker playing the exact same sound. If the peaks of the first sound wave line up with the peaks of the second sound wave, the overall sound gets louder. If the peaks of the first wave line up with the valleys of the second sound wave, they cancel each other out. Noise cancelling headphones have a microphone to \"hear\" the sound around you. They take what they \"hear\" and produce a sound that's the same, but shifted, so the peaks line up with the valleys. This cancels out the sound around you. Many people with normal headphones will crank them really loud to drown out the noise around them. This can damage your hearing. With noise-cancelling headphones, people don't feel the need to crank them because there's hardly any outside noise. No cranking means less damage to your ears, so noise-cancelling headphones can actually be beneficial. :)",
"Sound waves are made up of crest and troughs (loudness and silence). The loudness comes from the air getting pushed and pulled by the speaker. Now imagine what would happen if you could somehow set up another speaker that detects the sound and quickly emits the opposite. So if it detects and loud pushing sound, it'll emit an equally loud pulling sound. They would cancel each other. That's what a noise cancelling system does. It has a sound detector that converts sound into an electrical representation. That electrical signal is fed into an inverter which converts it into the opposite electrical signal. This signal is then fed into a speaker to turn it back into sound. Since it's the opposite sound to what was detected, they cancel each other out. This system only works because electricity is far far faster than sound, so the inversion process and the sound emission process are almost instantaneous, so they're able to cancel the original sound before it travels away. And no, unless the sounds involved are very loud, noise cancellation shouldn't damage your ears any more than the original sound might have.",
"Noise cancelling headphones do two things. They isolate the noise with the padding around your ears and muffle it a bit. Like what your regular headphones do. The second thing is that they have a microphone built into each side that records the abient noise and inverts the signal in real time. Constant sounds with constant bandwidth disappear ( like jet engine sounds in a plane). Irregular sounds with varrying bandwidth like talking are muffled and almost silenced because irregular sounds are hard to invert quickly."
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iryumk | How do they make vitamin tablets? | Where does the vitamin come from and how do they make it into pills? | Technology | explainlikeimfive | {
"a_id": [
"g54dol2"
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"text": [
"Vitamins can be derived from plant or animal products, or produced synthetically in a laboratory. Vitamin A, for example, can be derived from fish liver oil, and vitamin C from citrus fruits or rose hips. Vitamin C is water soluble, so all you need do is crush or grind the plant material and then shake it up with water. A common method is to grind the material with some clean sand in a mortar with a pestle. The material can then be filtered or centrifuged to get rid of the debris. The vitamin C will be in the water. The water is removed and what is left is made into tablets. Producing it synthetically just means that we have learned what basic chemicals make up the vitamin. Those chemicals in a very purified form are mixed together and put into tablets. Most commercial vitamins are made from synthetic vitamins, which are cheaper and easier to produce than natural derivatives. So vitamin A may be synthesized from acetone, and vitamin C from keto acid. There is no chemical difference between the purified vitamins derived from plant or animal sources and those produced synthetically. That said, some people react differently to the different versions and have a preference for one type or the other."
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is2yah | What makes a computer programmable? | Technology | explainlikeimfive | {
"a_id": [
"g550u5d"
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"text": [
"A computer at it's most basic level is just large network of switches. Similar to a light switch. The up position allows electrical current to pass through to the lightbulb and produce light. The down position cuts the current effectively shutting off the light. Programming languages just change the state of those switches to produce different results."
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|
is4ff3 | Why are most pc components green? | Technology | explainlikeimfive | {
"a_id": [
"g55cip5"
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"text": [
"Counterpoint: they aren't. For years the manufacturers have been making motherboard and GPU circuit boards black for aesthethics. Of course shitty OEM boards (and some PCIe cards) will be green, because printed circuit board manufacturers have that as the (completely arbitrary but \"traditional\") default. Different colors cost a tiny bit extra."
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is8iaz | How do calculators use logic gates to calculate? | Technology | explainlikeimfive | {
"a_id": [
"g56ex4i"
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"text": [
"You create logical circuits that do the operation you like. In addition, you make a full adder and change as many as you need together for the calculation. a full adder is added 3 bits, the carry from the previous adder, and one bit for each number. It output a result bit and a carry. Carry is overflow from an operation The operation is like you do when you add by hand on parer as you learned in school 35+26 can be split up. first adding 5 +7 to 12 so 2 out and 1 as a carry. Then you have 3+2 + 1( the carry from the precious operation= you get 6 out and 0 as a carry The result is the output in reverse order so 2 and 6 is 62 If you do that with binary you can make the 3-bit addition with simple logic [ URL_0 ]( URL_0 ) Multiplication and division is harder buy you split than just like you did when you learn to do them in school"
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is9mf4 | Why do photographs from the early 2000s (MySpace era) have 'that look'? | Technology | explainlikeimfive | {
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"g56jsed",
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"text": [
"Answer: it was the early ages of Digital camera's, Over the years camera technology have been refined a lot. Better sensors, better colour capture, better lenses. There where good Digital camera's back then, but they where very expensive. So it was common to have a camera with a very small sensor which had very basic features, poor quality lens that was 'always in focus' and nearly no enhancements. Plus a lot of people would use Webcams rather than a digital camera which will produce a much poorer picture. Edit_ Just to compare to today's prices, I bought a 256mb memory card for £85, you could fit around 2000 pictures on there (so small image size). These days you can get a 64GB card for around £20 Things where limited and seriously expensive compared to now.",
"Cell phone cameras were horrible back then. They took very small pictures. The images were grainy and didn't do very well when uploaded online. they also didn't usually have a flash and it was hard to get your face centered on it very well."
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isco3l | What is a data scientist and what makes them so valuable to companies? | Technology | explainlikeimfive | {
"a_id": [
"g5725o9",
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"text": [
"they basically figure out ways to collect and analyze data to determine how to better serve you with ads or influence your purchasing decisions or try and figure out what you're going to do. it can be as simple as figuring out the best type of ads to show you, to get you to click/purchase. or it can just be observing your movie/tv watching behavior and recommending you shows that you might like. or it can be trying to predict your presidential candidate choice (or political leanings) by the shit you post online/on social media. or it can be trying to analyze mass consumer behavior to predict what stocks or commodities might spike up or drop down in price. etc etc",
"We have two types of \"data scientists\". Firstly, you have the number crunchers. You give them a set of data, explain precisely what you want calculated, and they do all that hard math for you. You say, \"Here's our sales data. Calculate X, Y and Z for us.\" Nice to have, but at the end of the day, their function is similar to that of a calculator. Then you have the Data Scientists with a capital D. These are the ones who you say, \"Here's our sales data. How can we make more sales?\" The difference is that the latter can take a big set of data and extract meaningful, actionable results from it without having to be handheld through the process."
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isfe9o | Why can’t consoles be upgraded like a pc can? | Is it possible to swap out components of a console like you could with a pc? Is there anything stopping you swapping for example the gpu in a PS4 or Xbox for something better, assuming it’s compatible? | Technology | explainlikeimfive | {
"a_id": [
"g57hfk4",
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"text": [
"Because they weren't designed that way, while PCs were designed to be modular. One of the main advantages of having consoles that way is that developers only have one set of hardware they need to develop their games for.",
"No. Those consoles have their GPU, CPU and RAM soldered directly to the board. You can't just take them off and replace them with something else."
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isfugz | 5G would mean using internet, faster and better than it is currently. What is all this anti 5G about? | Technology | explainlikeimfive | {
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"My basic understanding of it is, people, have latched onto conspiracies that 5g is in the same wavelength as military weapons as well as a bunch of others conspiracies. The fact is 5g has been tested for decades and is safe to use.",
"Uneducated idiots that think that 5g is mind control, causes mental illness such as autism,. Causes cancer, causes carona virus. Basically, name a shitty thing in life, they'll blame it on 5g",
"Because some IDIOTS believe it acts as a carrier for coronavirus, there’s a whole conspiracy around it too.",
"All of the above, but I would like to mention that while the tin foil hats are all wrong, it’s easy to see where they are coming from because it will be very easy to see exactly where a person is and what they are doing in real time with 5G phones and in the wrong hands it could be a powerful surveillance tool."
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ishe0c | what, specifically, is being transmitted/received by my cell phone when using it and where does that data physically go to get to its destination? | I'm curious as to what exactly my phone is doing. Its a transmitter and a receiver. Well....of what? What exactly is being sent?? And where does that data being sent/received physically go? I'm aware of cell towers, but are they just one of many points of travel? | Technology | explainlikeimfive | {
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"Basically, the mobile phone network is very similar to the internet; your phone is like a computer, cell towers are like routers and there’s a host of technology on these devices which manages sending and receiving of messages. When you want to send a text you type it out on your phone. In the background that text is made into a data package which contains the text as a series of electrical signals. When sending the message your phone literally sends electrical signals (in the form of radio waves) to the nearest cell tower. Your phone knows which cell tower is closest because the phone is constantly sending out a signal which basically says ‘I’m here’ and the first tower which picks it up responds with ‘cool, I’m here’. That single cell tower is connected to other cell towers within its range (imagine a circle around each cell tower maybe 1 - 2km in radius, where the circles around different towers overlap these cells are connected and can send radio signals between each other), and those towers connect to still others to create a single network where signals bounce between different towers, so you can send a signal from Paris and this hops from cell tower to cell tower until it reaches its destination in Berlin. You might also find that the message spends some of its journey going through the internet instead of the cell network, because the system which provides the internet can also transmit and receive the same signals as your phone uses. That’s the bones of how cellular technology works - the two key technologies are signal modulation (creating a radio signal which your phone can encrypt as data and transmit, and your friends phone can receive and decrypt as text again) and networking (the cell towers in range with each other speak the same language and can send signals back and forth). In reality mobile tech is much more complex, you have to deal with how to make sure the network can manage lots of messages and avoid them getting jumbled up, how to find out the location of specific device within that network, how to manage longer data transmissions so that you can watch a video on your phone etc. The idea of different generations of cell technology (WAP - 3G - 4G - 5G etc) is that over time we’ve developed better ways to send and receive data through the network."
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isizf8 | Please explain how ads on social media work? | Because I litterally have never clicked on an ad on a newsfeed, or bought anything. Aren't they just losing money from buying my data? | Technology | explainlikeimfive | {
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"Even if you never do, some people will. Data collection is kind of like casting a net. Even if they *”miss”* you, they’ll “*catch*” a whole lotta others. So long as there’s a net profit to be made, data collection and targeted ads will continue. I’m guilty of clicking on a social media ad once or twice. Never bought anything but I did give the company some traffic. I have friends who buy stuff they see in ads all the time. I’m sure there are millions who do. Those of us clicking on ads more than make up for those of us who don’t",
"If nobody ever clicks, the company probably loses money. Companies lose money on advertising all the time, it's a gamble and it doesn't always work. Sometimes advertisements also help to just get the name of the company out. Even if I don't click the ad, I've still seen it and it's possible I'll mention it to someone else who might buy something or maybe I'll think of it next time I need a product like that."
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isjyqx | how does a digital watch know how long a second is? | Technology | explainlikeimfive | {
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"There's a few different ways. The most common in our life is a tiny quartz crystal that when supplied with a small voltage, vibrates at an incredibly consistent frequency, which our computer can measure.",
"Digital watches use a piece of quartz that when you apply electricity to it, it vibrates. The watch's electronics are able to count these vibrations. When a certain number of vibrations are counted, 1 second has passed."
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islpfu | Why does Windows have "Program Files" and "Program Files (x86)"? | Technology | explainlikeimfive | {
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"X86 = 32-bit programs, because Windows supports both 64-bit and 32-bit programs. Anything that goes into the (x86) folder runs through a different set of instructions to ensure it functions properly. URL_0",
"Program Files (x86) represents applications programmed for 32-bit operating systems. The reason to have the two folders is that you want to be able to install (potentially) a 32-bit and 64-bit version of the same application. Windows exposes a special Environment Variable for applications to call. They can ask for **%PROGRAMFILES%**. If a 32-bit program does it, they get the x86 directory, and if a 64-bit program does it, they get the non-x86 directory. This means that you can use the same code for working with both, and let Windows decide how to handle everything.",
"This is from when 64 bit processors were introduced. Most applications were 32 bit. This is fine as the new processors were backwards compatible so a 64 bit processor could run 32 bit applications. However it was not as simple as that. Because while the processor could run 32 bit applications this required 32 bit libraries (dll) and special handling by the operating system. So you ended up with sort of two different versions of the operating system, one for 32 bit applications and one for 64 bit applications. So it made sense to split these into different folders. You can see similar things on Linux and OSX. Most applications are now 64 bit so this is less of a problem and compatibility for 32 bit applications is going away."
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isn2ry | Why do militaries use depleted uranium in armor and ammunition | I have heard about depleted uranium shells and armor before but i wanna know why of all things you would use uranium as a metal compared to more conventional metal types. | Technology | explainlikeimfive | {
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"It has properties that make it ideal for military usage, both defensively and offensively. It's also cheap and readily available. **Density**- DU is very dense, which means it can absorb a lot of energy, like from the impact of an incoming projectile when used in armor plating. Conversely, as a projectile it can *carry* a lot of energy- meaning it can be highly destructive for its size when placed into the core of a conventional bullet or projectile. **Anti-Tank Weapons**- A big challenge on the battlefield is neutralizing enemy armor, such as tanks. Not only do you need a projectile that will penetrate its thick armor, but you also need to disable it- such as by killing the crew inside. A DU projectile can do both of those things because it has two very appealing properties- it fractures on impact into razor sharp pieces and it readily ignites into ferocious flames when it does. So with DU you have a high energy projectile that punches through armor plating, breaks into a swarm of deadly sharp spikes, and then incinerates the crew inside in a molten fireball. That makes it exceptionally appealing considering those rounds can be fired from a man-portable weapon.",
"It's really heavy. That's all there really is to it. There's a limit to how fast you can get bullets going, and the how-hard-it-hits factor is determined by speed times mass. So you want the heaviest (ie, densest, because there are also limitations on size) projectile possible. That's uranium. Pretty much everything else that people will tell you about uranium isn't really about how *uranium is great at this* as much as how *uranium doesn't suck at this as much as you might have though, considering we only picked it because it was super-heavy.*",
"It is as dense and heavy as metals can get. You want that in the core of bullet because more density/mass = more energy which, in turn = better armor-piercing capability. DU also tends to break apart into deadly shrapnel rather than mushrooming like other metals do. That can be devastating to the people inside the target.",
"It is very dense and it is really cheap to get since it's both found in nature and a byproduct of nuclear energy/production processes. The isotope that is used, U-235, only emits alpha particles so it's not *too* dangerous as long as you're not licking it or eating it. Alpha particles can be \"stopped\" by putting a few feet of distance between you and the radioactive source, or using virtually any kind of material (from paper to lead or anything in between) to create a shield.",
"Depleted Uranium is very dense. It's denser that tungsten so it does a better job of being heavy and still fitting into a cannon barrel.",
"The common answer is 'density' and that is pretty much right, but wait, isn't tungsten more dense than depleted uranium? Yes, yes it is. Keep in mind that this is for a military application. A depleted uranium shell going through armor is essentially incendiary, so whatever is on the inside of the target is going to get a flaming piece of metal flying through their compartment which will ignite things inside. It is a bad day for that target. Of you were in space and firing dense projectiles, you would probably stick with tungsten. In space the flame isn't that helpful, punching a hole in the side of whatever your target is and getting it to de-pressurize is very helpful."
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isvabq | why do digital images of the same size (width x height in pixels) have different size (megabytes)? | Technology | explainlikeimfive | {
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"Almost all images are stored in formats using some sort of compression algorithm. There are different types, and for a given kind, some images can be compressed more efficiently than others depending on the subject of the image. Solid blocks of the same color generally compress quite well. Also, some compression algorithms allow different levels of compression. They can get a smaller file size if you're willing to sacrifice some of the accuracy. Perhaps this thin stripe in an image has a shadow across it and actually requires ten shades of the same color to accurately reproduce but you can shrink the file by just making it all one color. Different trade-offs result in different file sizes."
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iswpfe | What was that dial up noise? Why was it always the same and why was it necessary? | Technology | explainlikeimfive | {
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"Dial up modems communicated using sound waves to represent digital data. The dial up noise was the \"handshake\" used between the two modems to establish a connection, determine the communication protocols in use at both ends, and conduct other tasks to set up the connection. The dial up sound is what that data sounds like to human ears",
"> What was that dial up noise? Modems (modulator-demodulators) > Why was it always the same It wasn't. Every conversation was a unique binary negotiation. If your ears were capable of distinguising sounds at up to 56,000 samples per second and comparing one sequence of 100,000+ tones to another sequence, you'd be able to tell they were not always the same. > why was it necessary? Before cable modems, DSL and fiber optic connections, all we had for \"getting online\" was the plain old telephone system (POTS) network. You want your computer to talk to another computer over the phone lines? Then your computer will literally need to \"talk\"--i.e. send audible signals--over the phone line, and the computer on the other end will listen and decode your computer's sounds."
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it5wsv | When you try to load a page, and it loads right as you press refresh, what happens there? | This may seem like a dumb question, as it could be purely out of coincidence, but could it have something to do with it cancelling the loading process to reload or something. | Technology | explainlikeimfive | {
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"It's not always coincidence! Sometimes when you see a part of the website flash just as you reload it's because the browser momentarily displays whatever it had already loaded, up until the point you hit refresh it was waiting for some data the website was supposed to provide but never did, so when you hit refresh this is aborted and the browser displays whatever it already has loaded, many times this is actually enough to make the website appear complete but maybe some functionality wasn't loaded yet.",
"Often times a browser will wait until images and other stuff within an element are fully loaded before it is displayed. Refresh button terminates the loading so it acts as though it is completed and shows the element anyway. That was more like 12yo explanation but oh well",
"If things are still loading your browser will often not display a page just so there aren't a bunch of bits popping up and moving around and being frustrating disorienting nonsense. When you tell it to give up, part of that routine goes \"oh things have stopped loading I guess we can show the page now\" but then the whole thing starts over right away."
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itdrrn | How was the first computer programmed? | Technology | explainlikeimfive | {
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"text": [
"The first computers were mechanical. Like those old school calculators/cash registers that had all the gears and wheels to do math, but on a massive complicated scale. So programming was really just, flipping a switch caused something else to move or happen. Then when electronics started to become part of the system, at the basic level they were the same thing, flip a switch, or series of switches, and something happens. Just this time it is electrical current instead of mechanical rods/gears. This “programming” then just gradually grew and grew and became more complicated as computers grew and evolved and became more complicated. Edit: this is just a fun fact that doesn’t answer the question, but one of the first reported cases of a bug being found in a computer, was when a computer stopped working and when the technicians opened up the casing, they found a dead moth."
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itf1sw | How do credit/debit card transactions work? | I have never owned a credit card, and I have never used a debit card for buying stuff online. In physical stores, I have seen people swipe/insert their cards into a machine. The machine shows the amount to be deducted, and sometimes the user enters a 4-digit PIN, and then the transaction succeeds. What prevents merchants from using a corrupt machine, that shows me "you will be charged $30" but actually charges me $1000? And what prevents the machine from scanning the card (and recording the PIN) and later buying things on my behalf? As far as I remember (from watching friends/family), to buy something online using credit/debit cards, we're supposed to give our card number (and maybe other info) to the merchant, and the merchant will communicate with our card issuer, and then the card issuer will pay the merchant. Is this correct? What prevents the merchant from asking the card issuer to charge me $1000 instead of $30? I see multiple things on a card - a 16-digit number, a 3-digit number, and a chip. There's also maybe a PIN that's not written on the card. What is the purpose of each of these? What information am I supposed to hide from other people to prevent them from buying things on my behalf? (I have used other online payment systems. In one of them, I login to my bank's website and confirm the payment, so as long as I trust my bank, there's no risk of losing $1000. It's like me telling the bank "pay this merchant $30" instead of the merchant asking the bank "charge this customer $30".) (My instinct says that something like 2-factor auth *must* used for credit/debit card transactions to make sense if the merchant is not trustworthy, but I'm not sure if my instinct is correct. Is this how it works?) | Technology | explainlikeimfive | {
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"Super simple version: Merchant scans your merchandise and gets an amount. They tell the cash register how to process the payment, if it is card they send an amount to the card reader that is to be charged. From that point it is out of their hands. You put in your card, the credit card company validates you have funds and it asks you to sign or ok the purchase. Once okayed you’re card details go through with the purchase information and then it returns the verification to the merchant and gives you a receipt to sign completing the transaction. Any unauthorized charges can be challenged and the merchant has to defend the purchase with your signed receipt or some other authorization or else they lose all the funds. This ability to challenge unauthorized charges is one reason to use credit over debit. They can change the amount. That is how waiters add your tip to the check when you go out to eat, but then you sign the receipt showing the change. If they put in $1000 instead of $30 you call the CC Company and tell them the charge isn’t correct and they will advocate for you. Even against big companies like Microsoft. A couple years ago I had pre-ordered a game for my kid and a charge showed up six months later and I questioned it. They refunded my card, took it up with Microsoft and Microsoft took the game back from my kid because now it hadn’t been paid for.",
"The reason merchants don't use a corrupt machine is the reason you should use a fake card: its the law! If a store does this they can get prosecuted and the card machine owners can refuse to allow credit card machines on that premises."
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ith1po | What’s the difference between 4G and 5G? | Technology | explainlikeimfive | {
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"text": [
"The radio waves used are different (different frequencies). Each \"G\" iteration has essentially meant that the signal that can carry more information, but less of a distance. That is to say, web pages and videos download faster on 5G, but it's easier to lose 5G signal. As a result, many more 5G \"towers\" must be installed to make it work since the signal can't travel as far or penetrate obstacles as well."
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ith7x0 | how come some websites work with www prefix and some websites dont work with www prefix? | what exactly does that prefix do and how does it impact the ability to pull up the web page? an example of a webpage that does not work with www is URL_0 and URL_1 I always assumed that if I do not put "www" in the webpage, it is ok because it get added in automatically either by the web browser or by some "internet magic" for lack of a better word, but those reddit pages are the first ones that I have come across that actually break cause of it, with the exception of "www2" | Technology | explainlikeimfive | {
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"text": [
"Whether a site works with or without www depends on the configuration of its main webserver. That is really just up to the administrators and the needs of their servers. If they're doing their job properly though, they should redirect you automatically to whichever one they use if you use the other, usually using a rewrite or redirect rule."
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itjetm | Sending messages on mobile devices - How does it actually work? | When I type a message in to my phone click "send", what is the actual physical process that happens and results in the message manifesting on my friend's device? I'm especially interested in wireless devices here, such as a cell phone. Does the message literally travel through the air? Is this data all around us every day but invisible to our eyes? Is it a gas?! What is it?! I'm looking for a extremely layman explanation of what is physically happening. Literally explain like I'm five, please. | Technology | explainlikeimfive | {
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"Radio waves! Inside your phone is a little antenna which can be energized with electricity, on and off, at a super high frequency - millions of times per second.When this happens, the antenna sends out invisible waves which can be detected by other antennas. When you send a text message, a picture, or talk in a voice call, basically the same thing is happening inside the phone: your picture, voice or text is converted into a pattern of radio waves, and your phone beams that pattern out through its antenna. Radio waves can travel through the air, through walls, even through outer space! They have trouble traveling through certain materials, and they get weaker the farther you are away from the source, though, so the cell phone company has to set up towers all over town to make sure you're never too far away from one of their antennas. So at the other end, your friend also has a cellphone with an antenna, which is also talking to the cellphone company's tower. The cell phone company receives the message at their tower from your phone, and figures out which phone it needs to be delivered to, and then sends it back out the same or a different tower, to be picked up by their phone."
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itkryo | How can google track you if you use search engines like Qwant instead if you use Google browser inside the Qwant. | Technology | explainlikeimfive | {
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"text": [
"Because google and other tracking cookies are on almost every site, not just their own search engine's site."
],
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itll0g | how do electronic devices know how full their battery is? | Technology | explainlikeimfive | {
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"text": [
"Simply speaking it is about voltage measurement. The device measures the voltage and from the device specs it concludes that it is at a certain equivalent battery level. There are most likely more advanced algorithms that can refine those results to give better battery level equivalents."
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itlqyo | how do the TL;DR bots work to reduce an article’s length? | It’s clearly not random or that would be almost unreadable, but I’m not a computer person and am just unclear on how it functions and still usually captures the core of whatever article it’s shortening. | Technology | explainlikeimfive | {
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"text": [
"The simplest answer is that you can use knowledge of a language to compare the importance of words and sentences and take only what is important. A by hand example of the above may produce this You use knowledge of a language to compare words and sentences and take what is important."
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itns8n | why do some emails arrive almost immediately after being sent, and some take a significantly longer amount of time, sometimes hours? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Could be network issues if you are referring to emails between the same sender/recipient. If it's between different senders each time, it could be the firewalls involved that are different between one site and another. Or maybe the path it takes has multiple hops. Could be the size of the email. So, it depends."
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itnu0r | What is the point of airplane mode? Does turning off airplane mode while flying genuinely affect the pilots? | Technology | explainlikeimfive | {
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"text": [
"Airplane mode turns off the cellular radio in your device, allowing you to continue to use the remaining features. It is theoretically possible, though unlikely, that the cellular signal emitted could interfere with aircraft electronics, and as a result the FCC requires cellular radios be turned off during takeoff and landing, the highest risk parts of flight. As a side benefit for you, you aren’t going to get cellular signal above 10,000 feet. You’re well above the highest cell phone towers, which are all transmitting downward. So leaving your radio on, your phone will continually seek a signal it can’t find and cause your battery to drain faster. So even if you’re not convinced of the “interference” risk, turn the radio off for your own sake. Edit: as correctly pointed out, the rule is an original FCC rule and not FAA rule.",
"There has been no recorded evidence of a mobile device interfering with a passenger plane in anyway. and the government body that made the no phones on planes rule is the FCC, federal communications commission, not the FAA, which regulates the airline industry and aviation. This rule mostly stemmed from fears in the public when phones were this new fangled thing, it helped calm peoples nerves. With smart phones that can do more than just make phone calls, the phone companies added a mode that only blocked what the FCC rule doesnt allow, phone calls/messaging in flight.",
"The real (historical) reason: cell towers. Cell phones are designed to have limited range. Their transmitters have just enough power to reliably reach nearby cell towers, taking account for various common obstructions like walls, nearby buildings, etc. This limited-range design is important because each cell tower can only serve a limited number of phones at one time. So each cell site are only designed to serve customers who are nearby. Now, when you’re on an airplane, suddenly there are no obstructions and your cell phone can connect with a large number of towers in more distant locations. If many people on many airplanes have their phones on, their connections could potentially disrupt various cell sites around the airport. This was especially true when cell phone signals were fully analog, but less of a problem in today’s digital world.",
"At this point it's mostly that the airlines don't want to deal with hundreds of assholes all yelling into their phones as they try to calls while sitting inside a super cramped metal tube 35,000 feet in the air. There are also occasional reports of instances where airplane electronics are unexpectedly vulnerable to RF interference, but generally these are required to be corrected once discovered. Previous to that, before the cell phone network was as robust as it is now there was a worry that huge numbers of cell phones moving at hundreds of MPH and in a position to have line of sight on dozens of towers would place a lot of load on the cell network as it tried to keep up as the phones hopped from tower to tower. Way back in the past there was actually possible for cell phones to goof up airplane electronics (mostly by generating noise that made the radios unhappy) but this predate cell phones being popular."
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itp8ny | Why do somePC programs require restarting your computer but cell apps never require a reboot? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"the thing is, most programs don't require a reboot, but they want you to reboot \"just in case\" there are any issues with the installation. you can generally ignore the reboot and the program will work fine. if it doesn't work fine and a reboot is actually required, then it means that something about the OS was modified, like a device driver needs to be loaded, but it couldn't be because something was in use/locked by the OS, or it needs to start a service that it can only do at boot time, or something along those lines.",
"Design. Cellular operating systems were more or less designed to be on 'always on' devices. They were also designed much later than desktop operating systems. Cellular apps are not really given as much access to the deep internals of the operating system and desktop applications can be. Finally, desktop OS has to deal with a possible change in hardware and drivers. Hardware on cellphones never really changes from the user side. On the other hand desktop OS architectures were designed more or less 50 years ago. In those early days, a computer would be something that you use like a microwave - use for an hour an turn off. As of 2020, most desktop programs do not really require a reboot - unless the program is dealing with something deeper in the OS or on the hardware/driver level. Still, the legacy of the 'reboot' continues, because it is more reliable and modern computers boot within a few seconds anyway."
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] | [
"url"
] |
|
itpbpp | how computers can keep track of time when they are completely turned off, even when they aren’t connected to the internet? | Technology | explainlikeimfive | {
"a_id": [
"g5fzn2n",
"g5fzn8i"
],
"text": [
"Because computers aren't ever really off unless left powered off and unplugged for a very long time. Even if you unplug one, there is a battery on the motherboard that keeps all your settings and keeps the time. That battery will eventually go dead, but it takes a long time.",
"In most computers, there is a small battery on the motherboard. This is used to power an internal clock, which is always running to keep track of the time. This battery can last for many, many years (think how long a watch battery lasts) because it is only really being used when the computer is unplugged."
],
"score": [
18,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
itpnry | Why are EV batteries a series of tiny batteries instead of one big upsized one? | I’ve been seeing videos of Tesla battery packs and they seem to be just a bunch of tiny batteries similar to AA batteries just stuck together. Why can’t just upsize the individual units to one big battery? EDIT: Just thought about it and wanted to add on, why are some batteries always a series of units and not just one big thing? | Technology | explainlikeimfive | {
"a_id": [
"g5g2mu1"
],
"text": [
"A few reasons: Regardless of the size of a battery cell, it produces a set voltage. This is based on the chemistry of it. All a larger size does is allow it to put out higher current and or hold a larger charge to last longer. AAA, AA, C, and D batteries are all the same 1.5V batteries. Them being different sizes doesn't change their voltage, but the bigger ones have more capacity. Lithium ion cells produce about 3.7V. Doesn't matter if it's a phone battery or a car battery. However, 3.7V is not going to drive a car. To get higher voltage (a few hundred), you stick the battery cells in series. Same as how many devices need two AA or AAA batteries in series to get the 3V they need to operate. Modularity. Making one large battery limits you. Making small cells means you can combine them into a variety of batteries of various capacity and form. Manufacturing defects and maintenance. A lot easier to swap out one faulty cell then abandon an entire large one. Cubed-squared law. Increasing the size of something increases the area by the square and volume by the cube. As such, just make a bigger battery of the same shape doesn't actually behave the same at all. The dimensions, cross sectional area, and volume are completely different proportions. Probably even more that Tesla engineers are very familiar with. Likely some safety issues with the volatility of lithium. Likely some intelligence in the batteries to use cells as needed for varying demand and abandon faulty ones without interruption. Could be some cooling considerations."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
itpysc | How do we have nuclear test footage? | How do the cameras and tape survive a test blast? Especially if buildings and inside buildings of the test area. | Technology | explainlikeimfive | {
"a_id": [
"g5g69lw",
"g5g3l7n"
],
"text": [
"Several types of cameras were used, but the standard ones were the Bell & Howell 16mm using a special emulsion to account for the x-ray exposure; film canisters were also lined with lead. Another type used was the Rapatronic camera. Shutter speeds were electrically controlled remotely from other bunker locations. Cameras positioned in the blast zone to show the effects of the 300 mph blast wave generated by the detonation were encased in specially constructed concrete-steel rebar mini-bunkers some with small apertures of singlass mica. They were thin transparent sheets \"isinglass\" mica layered together carefully to create a peephole aperture because they are less likely to shatter than glass when exposed to extreme temperature gradients.",
"I believe it’s a bit like how a GoPro sealed in a case doesn’t get damaged or ruined by being submerged. The cameras used to film the nuclear test footage were put in “bomb proof” cases with very thick glass and thermal protection. They were also placed quite a ways from the actual blast. I imagine it would be more or less impossible to protect a camera if a nuclear device was set off 2 ft from it."
],
"score": [
8,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
itq5d4 | Firefox 79 making links more secure, how does that work? | Technology | explainlikeimfive | {
"a_id": [
"g5gaxhn",
"g5gc7i9"
],
"text": [
"Back in the old days of the web, they made it so that when a link opens a page in a new window (or tab), the new page can edit stuff on the page that has the link. That's because it was useful for something and they weren't really thinking about security. In Firefox 79, it can't.",
"Let's say you're on URL_1 , and you click on a link that opens URL_0 in a new tab. URL_0 is a completely different website from URL_1 . However, because of the fact that the URL_1 tab opened it, browsers typically allow the URL_0 tab's webpage code (JavaScript) to interact with your URL_1 tab to a certain extent. For example, the URL_0 tab could cause the URL_1 tab to refresh the page or go to a different page. There are bad things URL_0 could do with this feature. At any time, it could make your URL_1 tab switch to an evil website that's made to look like URL_1 , to trick you into entering your login information or other private information. This would be surprising, since you don't normally expect a tab from one site to be able to do things to another tab. Some websites (especially old websites) might rely on this behavior for non-evil purposes. However, the Firefox developers decided that it's just too unsafe. Now, when URL_1 opens URL_0 in a new tab, URL_0 will normally not be able to interact with the URL_1 tab directly. If URL_1 really wants to allow URL_0 to interact with it, URL_1 can code the link a little differently to tell the browser that it's okay."
],
"score": [
8,
7
],
"text_urls": [
[],
[
"b.com",
"a.com"
]
]
} | [
"url"
] | [
"url"
] |
|
itqi5m | After a drop my flashlights LED turned blue, why is this? | After a 2 foot drop my flashlights light turned into a blue rather than the usual white, is there a reason this would be the case? | Technology | explainlikeimfive | {
"a_id": [
"g5g72l4",
"g5g7rg3"
],
"text": [
"White LEDs don't really exist. LEDs can only emit one wavelength oflight and white is a lot of wavelengths together. So white LEDs ar just blue LEDs with a layer of phosphor painted on them that absorbs the energy of the blue light and emits white light. You knocked that layer off. That LED must have been impressively shittily made, wow.",
"It could also be that the white LED was just a tri-color LED and the wires for red and green broke when you ropped it. This is not very likely though."
],
"score": [
10,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
itr72o | how it is possible to create nanometer transistors. | Technology | explainlikeimfive | {
"a_id": [
"g5gds0c",
"g5giej7"
],
"text": [
"The entire CMOS process is kind of hard to ELI5, as you need to know what a PN- / NP- transition is on the molecular scale. Anyway. The structures are etched into silicon wafers. In order to tell the acid where to etch and where not, a photosensitive paint is put onto a piece of silicon. The paint will become acid resistant under light. A special lamp and a laser-cut mask are put above it to literally print these structures into the paint. Then the thing gets washed with acid. This process is repeated layer by layer. Inbetween there will be some controlled diffusion of atoms with one more or one less electron into these layers. This will leave you with a layered stack of n- and p-dotted areas in the silicon which are basically the diodes the transistors are made of. This all can happen at scales, basically a couple of atoms wide. The limiting factor here is literally quantum tunneling of electrons inbetween transistor gates that are too close to another.",
"Get a sheet of special stuff. There's layers to it with some special properties, but whatever, it does some electrical stuff. If you cut out the right shape, it makes transistors. They've made lasers that a crazy-good levels of accuracy and can cut very fine lines. It turns out that photons are small. So they shine these accurate lasers at sheets of stuff and what's left is a computer processor or whatever."
],
"score": [
8,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
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