q_id
stringlengths 6
6
| title
stringlengths 4
294
| selftext
stringlengths 0
2.48k
| category
stringclasses 1
value | subreddit
stringclasses 1
value | answers
dict | title_urls
sequencelengths 1
1
| selftext_urls
sequencelengths 1
1
|
|---|---|---|---|---|---|---|---|
aoshmo | the point in keyboard sticky keys | Technology | explainlikeimfive | {
"a_id": [
"eg36qwt",
"eg3fx8t",
"eg36otj",
"eg3b1r0",
"eg3hp6w",
"eg3n117",
"eg3b57f",
"eg3cj3q"
],
"text": [
"To enable people whow lack full function of both of their hands to do hotkey combinations. Example: A person with one hand cant do ctrl-alt-del on most keyboards. So press shift 5 times, tap each key individually, and then turn sticky keys back off by pressing shift 5 times again.",
"I used sticky keys recently to break into an old windows 7 machine we had forgotten the password to. Go into recovery mode, find a command prompt window, copy the sticky key command, copy the cmd.exe command to your sticky key command copy, head back to login screen, activate sticky keys which now opens command prompt, type in net user and change password. Voila, thank you sticky keys",
"Some people have problems pressing two keys at once. Sticky keys let them use key combinations.",
"It's an accessibility feature for differently abled people. It metaphorically makes the keys sticky so that when you want to use functions using any combination of keys like Shift, Ctrl, Alt, Del, you don't have to press the keys simultaneously.",
"I started using sticky keys when I had an injury in my right hand. But have continued using it even after recovery, as it helps prevent RSI (e.g. Carpal Tunnel injury) .. turns out that repeatedly stretching your fingers to use Shift is bad for your tendons",
"Let's say you want to press Ctrl Alt Delete. If your hand isn't flexible enough to reach all three keys at once, then you can't do it. But if you enable sticky keys, you can press the keys one at a time and Windows will still recognize the combo. The Ctrl key will \"stick\" down until you execute a combo (or, I believe, if you press Ctrl again). You might not have any use for this, but it's very convenient for elderly people or people who have lost fingers, because every function of the keyboard is possible with only one finger.",
"Anyway how do you disable it? It's super annoying for someone that doesn't use it ever.",
"Just the other week I was working on setting up the [layout]( URL_2 ) of a [Gherkin]( URL_4 ) 30% keyboard for my [Minidox]( URL_1 ) 35% keyboard. Since there are only 3x2x5 = 30 keys on a Gherkin, I have a hard time finding a good place for the various shift keys, so I'm thinking about employing sticky keys to make certain key combinations possible. The [ URL_0 ]( URL_0 ) open source keyboard firmware already have [extensive support]( URL_3 ) for this. My motivations for looking into this topic are 2 fold: 1. as I'm getting older I'm more and more afraid I will injure them with typing 2. I would like to speed up my typing when I chat or write some kind of prose and make writing code more comfortable and less tiring I do *not* have any permanent issues with my hands, yet such seemingly funky features can aid to achieve my goals."
],
"score": [
10965,
696,
386,
83,
45,
36,
19,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[],
[
"https://qmk.fm",
"https://falba.tech/customize-your-keyboard/customize-your-minidox/",
"https://github.com/onetom/qmk_firmware/blob/7f3be69ee9f3e194e5fedf923d3c0c596d8aa0f9/keyboards/minidox/keymaps/onetom/keymap.c",
"https://docs.qmk.fm/#/feature_advanced_keycodes?id=one-shot-keys",
"http://www.40percent.club/2016/11/gherkin.html"
]
]
} | [
"url"
] | [
"url"
] |
|
aotz86 | why toilets are made of porcelain | Technology | explainlikeimfive | {
"a_id": [
"eg3uscj"
],
"text": [
"Porcelain doesn't absorb water, doesn't stain easily, is durable and attractive and easy to clean, and works great for plumbing fixtures."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aowmye | How do pool tables know which ball is the cue ball when you scratch? | Technology | explainlikeimfive | {
"a_id": [
"eg41qnr",
"eg41o3v"
],
"text": [
"Usually, the cue ball is of slightly different diameter so it can be mechanically sorted out. In some machines, the cue ball is the same size but has a metal core that trips a magnetic field sensor and electronically triggers some kind of separating device.",
"Bar table cue balls are designed with a slightly different size and weight so that the return mechanism allows them to pass through. In an older set of balls the cue ball may be slightly lighter or smaller because it is the only ball that is hit every play, so it takes more abuse than the others. In a regulation set the cue ball is the same size and weight as the other balls. A web search will provide more information and is probably quicker than ELI5..."
],
"score": [
8,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aoz4sd | How do QR codes work, and why can my phone recognize one before I get the entire thing in view of the camera? | Technology | explainlikeimfive | {
"a_id": [
"eg4oao2"
],
"text": [
"QR codes work in quite a complicated way, but the short answer is that they're designed to continue working even if damaged. You can cover something like 1/3 of the code and it'll still read, which is how the QR codes with logos and things in the centre still work - they aren't cleveley generated, they're just slapping the image in there and trusting to maths that it'll still work. That's why the phone can read it before seeing the whole thing - it's using the redundancy built into the code."
],
"score": [
26
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ap198z | how is paperless better than paper if paperless needs constant energy to be viewed | Technology | explainlikeimfive | {
"a_id": [
"eg52moy",
"eg552vw",
"eg52ga2"
],
"text": [
"The amount of power it takes to view and store an electronic document is much lower than the creation of the paper and the fuel it takes to be driven/flown to your city. It also doesn’t go into a landfill or burned.",
"A lot of things with \"paperless\" options are things you'll look at once, maybe even not at all. Like your electricity bill. I have my bill set to automatically be paid every month. Every month I get an envelope in the mail with 3 pieces of paper, and a return envelope in case I want to mail in a check. All I do is glance at the total, say \"huh, that's like $10 higher than I was expecting\" and throw everything in the trash. Think about how much energy and waste went into making those envelopes and paper. Getting from the factory to the power company's printer. Then being hand delivered by mailmen across the country. All so I can see what I was charged. A text message could replace that bill. Now imagine hundreds of millions of people getting the same bill, every month. And one for each utility, each credit card, etc. That's a lot of unnecessary paper, ink, and delivery labor. What a waste.",
"Not trying to start any shit but it’s something I always wondered please educate me"
],
"score": [
10,
9,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ap6b7i | How do videogame hacks work? | Technology | explainlikeimfive | {
"a_id": [
"eg62y9f",
"eg61haa"
],
"text": [
"I'll give you a classic example. The Game Genie - If you are not familiar with it, this was a device on the original NES that plugged in between the game and the console and was used to cheat in video games. The way it worked was by altering variables in the games code. So how many lives you have is a variable, a number stored in memory. The creators of the Game Genie reverse engineered the game, figured out which variable stored the number of lives, and altered the signal as it came out of the cartridge. So instead of starting with 3 lives, you could start with 6, or 9, or even unlimited lives depending on how the game was designed. What they could do and alter depended on how the games code was designed. For instance a game might have a line that triggers a Game Over when you reach 0 lives. But that line only triggers at 0, and if it doesn't have any logic regarding negative values you can pull pull a trick. You can set the value to -100 (which would never happen in the games normal operation) then you can gain and lose lives but the game will likely never reach 0 to trigger the Game Over. Hence infinite lives.",
"A lot of times they involve changing values the game has loaded into memory - like figuring out where the game has stored how many lives you have and changing the number to 999. Other times it can involve something more simple like altering .ini settings and such."
],
"score": [
7,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ap837q | How does public school wifi block sites without using software? | My school blocks websites on their computers and on my phones/laptops, even though I clearly didn't install any software to block websites. How exactly does this work? Does the school wifi use an ISP block or something similar? | Technology | explainlikeimfive | {
"a_id": [
"eg6dta9",
"eg6izym",
"eg6e127",
"eg6ef6c",
"eg6zdpy"
],
"text": [
"The trick is that the school controls the entrance/exit to the Internet. With software processing the traffic that glows in/out they can control what you can actually connect to and sometimes replace the responses your computer received with their own. This is usually implemented as with a firewall (control what you can actually connect to), DNS injection, and transparent proxying.",
"Think of your computer's access to the internet as a bunch of letters. The school's firewall is the mailman. The sites you want to go to is the addresses on the letter. If the address on the letter is a blocked site, it gets sent to a different site where it says blocked. If not, it goes through no problem. A VPN sends your letter in another letter to a normal address. Once it gets to the first address, it opens the letter and sends the letter elsewhere.",
"You have to connect to a router, which likely has firewall settings configured. Your laptop itself is not blocking traffic to a certain site, but rather the router will not let you send/receive traffic to those specified sites. Its a little more complex and I left a lot of details out, but that’s pretty much the barebones.",
"They do use software, but it is on the school processing servers and routers. The Internet comes into the school and connects to their servers and routers before it is sent out to their WiFi broadcast nodes and hardline drops. There is no need for software to be on your device because they block it on their side.",
"Cyber security analysts and former firewall jockey here. So, imagine connecting to websites is like making a phone call and you have a really bad memory. Every time you want to call someone, you look up their name on a phone book and then dial their number. What your school does is as if they hold onto the phone book. Every time you want to call someone (connect to a website), you ask for the phone number for a specific person (translate the web sites address into an IP). The school can then decide if you're allowed talk to that person and if you're not, they won't give you the phone number. In the case of you connecting to a website, the network equipment just won't give you the IP for the website you want. Another way is to do the equivalent of looking at the name in the address of an envelope. They can't open the envelope without the recipient knowing it was tampered with but they can see who you are sending mail to and then decide whether or not to pass it along to the postal service. This analogy is for when your school's network equipment looks at the packets itself and identifies the domain you are trying to reach. In the case of HTTPS traffic, it looks at the certificates used in the encryption process and decides whether or not to allow the traffic based on the domain name in the certificate. I'll let me know if you have any further questions. This is actually large part of my work so I have a lot of experience with this very subject."
],
"score": [
51,
41,
16,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
ap8vp2 | Why are gas stoves, ovens, and water heaters so common? | ELI5: Why in most places are electric appliances not the most common yet? For example Mexico. | Technology | explainlikeimfive | {
"a_id": [
"eg6jicp",
"eg6jxrr",
"eg6jfsq",
"eg6yan9",
"eg6jh7d"
],
"text": [
"Electric appliances that heat do so through resistive heating. They literally run a lot of electricity through stuff that naturally resists electric flow (current). In the process they create heat. It’s a pretty wasteful process and tends to be a lot more expensive than just burning an already energy dense material like natural gas.",
"Gas stoves are better than electric stove tops. You have better control of heat levels as there is not a coil that has to heat up or cool down so all adjustments are immediate. Electric ovens can be better than gas, but most combined stove-oven units will have gas ovens if they have a gas range. So if you go for the superior stove top you end up with the slightly inferior oven. As for water heaters, that depends on preferences. Gas options can be cheaper to operate than electric depending on the cost of natural gas and electricity in your area. They will also heat water faster so if you have a large family using up the hot water in showers and the like you may want the gas to meet needs better.",
"Well, simply from a cooking standpoint, gas stoves and ovens are WAY superior for cooking than electric. Gas is much better, faster, more consistent, often hotter, and overall much easier to cook on than electric. As long as your supply of gas isn't an issue, gas would almost always be chosen of electric for cooking stoves and ovens. Hell restaurants would revolt in much of the world if they had to go to electric cooking methods. They need the flame, heat, and ease of gas cooking to pump out those dishes. The only reason you would generally choose to go electric, is if gas was not reliably available.",
"As has been stated, electrical heating is garbage compared to gas. And cheaper. Also works without electricity.",
"They are common because they are affordable in developed countries for most people. It is considered as basic, cheap technology in these countries."
],
"score": [
8,
6,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
ap9m50 | Why do some TV adverts have out of sync audio | Technology | explainlikeimfive | {
"a_id": [
"eg6pho5"
],
"text": [
"Often because they were originally shot in another language (German ones are common on British TV) and have been dubbed on the cheap."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
apb0k9 | How do instant fog windows work? | I’ve been seeing videos of windows/doors that are clear, but turn foggy once a button is pushed or the door is locked. How does the window turn back and forth from clear/foggy. ELI5 pls | Technology | explainlikeimfive | {
"a_id": [
"eg762ih",
"eg78jzh"
],
"text": [
"Liquid crystals embedded in the glass are activated by electricity. They then turn and scatter light that tries to pass through them.",
"Switch glass has two sheets of glass. Inside those panes of glass are electrically charged sheets and between those sheetd are liquid crystals. When turned off, the crystals are randomly distributed creating an opaque or translucent effect from the scattering of light. When power is applied, the electrical charge forces the crystals to align neatly to the electrically charged sheets causing the window to appear clear."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
apd011 | Nexplanon IUD. How does it slow release the birth control hormones for 5 years? | I understand extended release pills and such, but how does the mechanism for Nexplanon (fka Implanon) work? It's not powered in any way and five years is a long time for something to be consumed by the body. Thanks in advance! | Technology | explainlikeimfive | {
"a_id": [
"eg7i4pa",
"eg7heu1"
],
"text": [
"First off, Nexplanon is an implant. It's not an IUD because IUD means intrauterine device and goes in your uterus whereas this goes in your arm. The contraceptive implant was invented by [Sheldon Segal and Horacio Croxatto.]( URL_1 ) The implant outside layer are tubes are made out of silicone, which the body can't dissolve. in the middle of a tube, the hormone (progestin) is mixed into a slowly dissolving polymer. There is also a membrane that covers it. Water can get in, but the membrane slows how fast the drug can leave. By tweaking the surface area, the solubility of the polymer, the concentration of the drug in the polymer, and the diffusion rate of the membrane, you can control how fast the drug is released into the system. So think about the Grand Canyon. Water flows through it and slowly erodes the rock and carries it to the sea. Erosion can be where water physically moves the rock, or it can be chemical erosion where something like salt is dissolved into the water and carried away. In the case of the implant, it's chemical erosion and it takes 5 years for it to be fully dissolved. [Here's a paper if you want more details.]( URL_0",
"The way I understood it is like your body just really slowly absorbs the hormones out of it, the material is just thick enough to hold in the hormones but release a little i suppose? my doctor didnt explain it very well but also Id like to add, im pretty sure its only approved for 3 years, at least thats when I have to get mine changed. also, might be better to try r/Nexplanon"
],
"score": [
8,
3
],
"text_urls": [
[
"https://watermark.silverchair.com/56-3-739.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAkMwggI_BgkqhkiG9w0BBwagggIwMIICLAIBADCCAiUGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMWEFXUzPV8iwZFPF3AgEQgIIB9tP3ML05riWH5ZfAMLbNpzENAI1IWbvhhsDBdcZ7DLzUqctcAZEWHTT2p-d-CtvfZBbDvlS39WlziawBlENX7_Cy-mjRol4JytZ25WDFzPIleLC7PjNI0Zj4n2O1m25gWTnK1cDzRORun7-PjIR2DM2e_uTbChkgySMKRg46Q-C0qr6s0YnMxp3UEsGvW1ZMglMJrQzSCRWGMeIYWG5xzvULdv-s1a-8q2SzmQtO6hm5kxLan1ssXagGQEGbPwYEuPQ6s0krCHu0VLuPBYQmwAS5bPcec7KxBqUTY",
"https://en.wikipedia.org/wiki/Sheldon_Segal"
],
[]
]
} | [
"url"
] | [
"url"
] |
apf0s4 | Why do supercomputers use GPU instead of CPU ? | Technology | explainlikeimfive | {
"a_id": [
"eg7u8yg"
],
"text": [
"The kinds of problems you use supercomputers for tend to be things that do lots of math with lots of numbers without thinking too much about it. GPUs are great at applying fairly simple logic to lots of numbers at once because they're able to run the same instructions across a thousand sets of numbers at once (and you can build each node to have 4 GPUs without a problem) CPUs tend to be better at complex, branching logic but they don't have near as much parallelism - a monster server might have 100-way parallelism on the CPU."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
apf9sa | How do QR codes work? | Technology | explainlikeimfive | {
"a_id": [
"eg7twua",
"eg7u2ak"
],
"text": [
"They are like a barcode and translate into a link that shows you the information at the end",
"They are just bunch of ones (black part) and zeros (white parts). All computers think in ones and zeros so they don't have a hard time reading information out of QR codes. And yes, you can theoretically read them \"manually\" but you'd have to learn the whole QR code protocol (how the data are organized, what encoding do they use and also memorize the whole table for that encoding - for example [ASCII table]( URL_0 ) )"
],
"score": [
5,
3
],
"text_urls": [
[],
[
"https://i.stack.imgur.com/iCOov.gif"
]
]
} | [
"url"
] | [
"url"
] |
|
apg1ln | How is rock removed to expose a fossil without damaging the fossil? | To me, it's all just rocks, so I don't understand how a paleontologist is able to differentiate and remove rock from a fossil, whether it's bone, shell, plankton, bacteria, plant matter, & cet. What techniques are used in the preparation of the specimens seen in museums? | Technology | explainlikeimfive | {
"a_id": [
"eg8dmmz",
"eg8emof"
],
"text": [
"Yes, by the time they are fossils, they are all \"just rocks\"; but, importantly, they are different kinds of rocks. When a bone gets fossilized, the chemical makeup changes, with minerals replacing some of the components of the bone. This forms crystals which are often harder than the surrounding sedimentary rock. So, you just scrape away the sedimentary rock and you have your fossil. Of course, you have to have the right tools so that it only takes away the stuff you want and not what you don't. It's tedious and time consuming. There are actually different processes depending on both what you started with (bone vs shell vs soft parts etc), what it went through over time, and then what sort of rock it ended up in. Some fossils are more like prints, where there is just the outline of carbon left over but no shape; some are more like casts, where you can tell the shape but there really is nothing left of the original. Here is a link to different ways it occurs: [ URL_1 ]( URL_1 ) The chemical changes during fossilization are still under study. Here's a relatively recent publication: [ URL_2 ]( URL_0 ) . That paper has a great section called WHAT IS ‘‘FOSSILIZATION?’’ that talks about what happens and why from a chemical point of view.",
"I picked a couple of fossilized leaves this summer. The leaf was very different to the rock around it, and several of the rocks i found split apart at the leaf when i tried cracking them open. The leaf surface is smooth and hard, while the rock around it is porous, letting cracks easily form in the plane of the leaf."
],
"score": [
24,
3
],
"text_urls": [
[
"https://earth.boisestate.edu/mattkohn/files/2010/07/2008_Kohn_Diff-models-fossils.pdf",
"http://www.fossilmuseum.net/fossilrecord/fossilization/fossilization.htm",
"https://earth.boisestate.edu/mattkohn/files/2010/07/2008\\_Kohn\\_Diff-models-fossils.pdf"
],
[]
]
} | [
"url"
] | [
"url"
] |
apgmlc | Why is it so difficult to make reflections in video games? | Why is it so difficult to make reflections in video games? Is it impossible to do without a very large consumption of resources? | Technology | explainlikeimfive | {
"a_id": [
"eg83q6t",
"eg83k2b",
"eg8aefd"
],
"text": [
"Doing a reflection essentially means drawing the scene twice, once from the camera's point of view and once from \"within\" the mirror. Drawing the scene takes a lot of processing power. If the game runs at say 60 fps normally, having to draw the scene twice will make that framerate drop significantly. That said it should be possible if the developers are clever about where they place mirrors. For example if a lot of the game has wide open spaces with lots of stuff in it, but mirrors are only ever in enclosed spaces with not much in them then it could work ok. But it's still a lot of work to implement mirrors, and generally do players care about them that much? The time is usually better spent on other features.",
"It isn't difficult to make reflections in video games, but it isn't *easy*, and to make a game run at a reasonable frame rate while maintaining the graphical fidelity people have come to expect you need *all* your graphics to be easy. For one thing, to make a mirror reflect what's behind you, you need to actually render what's behind you, then calculate the angle from each point on what's behind you, bounce it off the mirror, to enter a pixel on your monitor - all of which can be done in less than a millisecond and in massive parallel using modern hardware and raytracing techniques, but that still makes each frame take some fraction of a second longer to calculate. Unless being able to see what's behind you in a mirror is important to the game, most prefer to just not do that. As far as reflections in horizontal surfaces such as water, there are some fast ways to approximate those but they're pretty easy to get wrong. A small mistake while implementing them lead to very obvious errors in the way the world is reflected.",
"Beyond all the talk about not preferring to render behind your character, reflections only mean much of anything in first person games. And if they will have mirrors, then they also have to have a decent character model and animations. The model they certainly have anyway for cutscenes and promotional work. But the animations they may not. I believe Wolfenstein and Duke Nukem had each used mirrors, and your character was just a static model strafing in front of the image."
],
"score": [
33,
23,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
api3i3 | How does the UNIX tool grep work so quickly? | Technology | explainlikeimfive | {
"a_id": [
"eg8h77t"
],
"text": [
"It implements the Boyer-Moore algorithm. You begin by preprocessing the pattern to generate a rule table, which I'll mention again in just a moment. You match the pattern by it's last character and work in reverse. If the pattern doesn't match, then the principle key to the speed of this algorithm is that you skip ahead a number of characters based on the rule table, the size of the skip per rule is dependent on the pattern. Grep uses some clever programming to get the number of instructions per character down. It unrolls loops and relies on table lookups as much as possible. It also skips the C standard library and goes straight to kernel calls, and it operates over the whole input buffer and does not first break the input into lines. It also doesn't copy data in memory. Finally, the larger the pattern, the more efficient Grep becomes, by virtue of being able to skip over more and more of the file at a time."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
apibgh | How do grep's algorithms work, and what optimizations were made to it? | Technology | explainlikeimfive | {
"a_id": [
"eg8j5u2"
],
"text": [
"Take a look at the very thorough post from RipGrep’s author. URL_0"
],
"score": [
4
],
"text_urls": [
[
"https://blog.burntsushi.net/ripgrep/"
]
]
} | [
"url"
] | [
"url"
] |
|
apjzep | How come noise cancelling headphones don't increase hearing loss when there is actually more sound being produced around your ears? | I understand that passive noise cancelling headphones are good for your ears because they have and insulant that keeps some of the sound from outside sources from reaching your ear. What I don't understand is the active noise cancelling technology that records the audio on the outside of the headphones and produces sound waves of the opposite amplitude on the inside. Wouldn't these extra sound waves exhaust your ears and potentially damage your hearing? | Technology | explainlikeimfive | {
"a_id": [
"eg8zvk8"
],
"text": [
"That's the whole point of the opposite amplitude, the two waves cancel each other out and the eardrum doesn't move at all as a result. So the additional sounds actually result in less movement of the eardrums, and thus are easier on your ears. People who work in noisy environments (like a data center), even if the volume isn't enough to be classed as dangerous, often eventually lose their hearing in the band of frequencies the sound was in. That's due to the cilia in the inner ear in that zone being worn away."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
apmd96 | If I have a laptop that runs HD graphics connected to a HDTV that runs 1080p via an HDMI cable. What do I need a monitor for? | Technology | explainlikeimfive | {
"a_id": [
"eg9jidb",
"eg9jmgl",
"eg9lfsc"
],
"text": [
"Depends on what you’re using it for. Particularly, if you’ll be gaming, TVs experience much more “lag” than monitors. Other than that, there aren’t many things monitors do better.",
"A monitor is generally better than a TV in terms of quality up-close. For work or gaming, you definitely should use a monitor. It’s too far away to be effective for focusing on work, and if you’re using to game, it’ll help you focus on your game better. The input time from your mouse or keyboard is longer to the TV than to the monitor. TL;DR: It maintains the quality of an HD TV but up close, with less screen tearing and other factors and less input delay.",
"Size, Response Time and Pixel Density. I can play games on a 10' projector screen, but to be honest it's just too much physical space to watch. Monitors can show all the detail I need without being too big for my brain to process. Have you ever tried to read Reddit on a TV? For most (cheapish) TV's, the text gets all blotchy and weird. Gets really annoying. TV's are meant to show moving images that aren't text. They don't have as many pixels per inch that a monitor does, and rely on your brain to fill in the blanks. If you've ever played a competitive first person shooter where twitch speed really matters, the lag in signal from the laptop to the TV can actually be noticeable. Monitors process the signals better and faster. There are TV's that have monitor-level stats, but they're so expensive extra monitors would be better. But if you're playing single player games using a controller just to veg out at night, a TV can be perfectly fine."
],
"score": [
7,
5,
5
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aprirm | Why/How do electronics such as phones interfere with equipment in places like hospitals? | Technology | explainlikeimfive | {
"a_id": [
"egaozqs",
"egaz85x"
],
"text": [
"There can be lots of reasons for signs like these. Firstly they may not want people to take pictures or record the sound or things of that nature. They might have sensitive information such as patient journals readily available or they expect some privacy for the patients, doctors and loved ones. Secondly there may be things present in the rooms which are dangerous to electronics. Such as powerful magnets, x-rays, radiation, gasses, etc. The third reason should not be a problem for well designed and maintained equipment. However in some cases you want to have more then three layers of safety. Some equipment might generate a spark, this is not that uncommon when there is a grounding error for instance. It is also possible for some radio equipment to induce a current in nearby signal wires, for example if you put your phone right next to the speaker wires and there is a terrible sound coming from the speakers. Well designed equipment should handle this gracefully but there may be issues causing it to misbehave.",
"If you've ever had your telephone next to a stereo system when a call was coming in, you've probably heard the noise that gets picked up by the stereo, even if it's not tuned to a radio at all. This is because the lower harmonics of the cellphones radio waves, are in the frequency of sound waves, 20hz to 20,000hz that we can hear, and the audio amplifier in the stereo picks up these waves and amplifies them. This is a real world example of how having a cell phone close to electronics can interfere with them. It is very difficult to play just 1 pure tone. For instance when you strike the A key on a piano, it might primarily vibrate at 440hz, but it also vibrates more quietly at 880hz, and higher frequencies, all the way up until they are so high we can't hear them anymore. We call these harmonics and it's a natural side effect of creating waves like sound or radio. In the realm of radio waves it's possible for the harmonics of one radio frequency, to interfere with a 2nd frequency that is nowhere near the original. For instance the 2.4ghz wifi signal of a phone interfering with the 64mhz frequency of an MRI machine. Waves follow something called the inverse square law which means that the energy of a wave falls much faster the farther it is from the source. For instance the power of a radio transmitter seems 4 times lower at 2 meters away than it does at 1 meter away. It's twice the distance but 4 times quieter. So the closer a radio transmitter is, the more powerfully it can disrupt other radio equipment around it. This means a small transmitter close by, like a cellphone in your pocket, can be more disruptive than a large and powerful transmitter farther away, like the cell towers around the hospital. Ironically the reverse is also true. There is equipment in hospitals that is far more powerful than those same transmitters that give you cellphone coverage. Their energy is enough to damage your phone and other electronics, or even hurt you. For instance you wouldn't want a cellphone in the same room as an MRI for safety reasons."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aps9od | why did old internet modems make all those noises and did they serve any purpose? | Technology | explainlikeimfive | {
"a_id": [
"egarybo",
"egasx5x",
"egas1qb"
],
"text": [
"[They absolutely have a purpose]( URL_0 ). & #x200B; And modems play them back to give you the possibility to find problems in the connection by listening to it: Is the line busy? Did a person (instead of a modem/fax) accidentally pick up at the other end?",
"Old style modems functioned by transmitting data over analogue telephone lines. They basically tuned the data they were sending into a series of computer generated sounds and then send those sounds over a normal telephone line. Very old modems were basically just a speaker microphone that you put your telephone handset onto to let it \"speak\" and \"listen\" over a regular phone. Later version could be plugged directly into a phone line next to a regular phone and created the noises internally. It would be silent for most of the time since the sound of the actual data transmitted was not really all that interesting, but the sounds at the beginning when the modem performs a handshake with its remote counterpart was useful. If you knew what to listen for you could tell exactly what happened and what didn't happen. So you could start troubleshooting by listening to the modem trying to make a connection. Later as modems became more common fewer and fewer owners could actually do anything useful with the sound, but having the sound of the connection being established be played out loud was the default (you could turn it of if you knew what you were doing). So more and more modem owners had a modem that made sounds that they didn't have the technical know how to either find useful or to turn off. Eventually it was just one of those things that computers did and that everyone expected them to do. By the time winmodems and similar cropped up they stopped playing the dial up sound out loud but some models actually played a sound clip of the typical sound because that was what people expected.",
"The frequencies of the modem's sounds represent parameters for further communication. In the early going, for example, the modem that's been dialed up will play a note that says, \"I can go this fast.\" As a wonderful old 1997 website explained, \"Depending on the speed the modem is trying to talk at, this tone will have a different pitch.\" That is to say, the sounds weren't a sign that data was being transferred: they were the data being transferred. This noise was the analog world being bridged by the digital."
],
"score": [
11,
8,
3
],
"text_urls": [
[
"https://www.youtube.com/watch?v=abapFJN6glo"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
apsl4f | We get Internet from ISP. From where does ISP get Internet and how? | Technology | explainlikeimfive | {
"a_id": [
"egausaw",
"egb6gxw",
"egb36ty",
"egb9qfi",
"egb6yej",
"egbgw5y",
"egbk8mi",
"egb4n81",
"egatpnb",
"egbt65n"
],
"text": [
"Your ISP likely gets its internet connection from another ISP. That ISP may also get its internet connection from another ISP. ISPs are generally considered Tier 1, 2, or 3. Your ISP is likely what is considered a Tier 3 ISP meaning they focus on providing the last mile to internet users. They then likely connect to another much larger provider who also connects other Tier 3 providers. This provider is generally considered a Tier 2 and then connects to a Tier 1 which are your backbone Internet providers. Tier 1 providers don't actually pay for service. They have invested so much into their infrastructure and are so large that they enter into agreements with other Tier 1 providers to form the backbone of the internet. Tier 2 providers may blur the line between 1 and 2 and enter into similar agreements or may pay for service from a Tier 1 provider. Edit: 1 exception to this is Comcast which blurs the line between all 3. Also ATT, Sprint, and Verizon are considered Tier 1.",
"The ISPs *are* the internet. The internet is simply a huge amount of *inter*connected *net*works. When you go online, you form a tiny part of the internet, and could be a tiny ISP as well. In fact you pretty much are if you run a wireless access point.",
"The answer given by /u/nmbgeek is mostly correct (and would have been completely correct 4-8 years ago). Today with the emergence of IXPs (Internet eXchange Points) even the smaller ISP's are getting on on settlement-free peering (not having to pay for all of their traffic) Let's take this from the perspective of a smaller regional ISP (which would have been a Tier3.) We serve around 8000 homes and use ~15Gbps of 'Internet'. Being in the middle of nowhere, we have very limited local options to get our Internet from. So we buy some access from a larger regional Tier 2 on our border just as in /u/nmbgeek's example (which is mostly only used if our other connection detailed below has an issue as a backup). We also lease a dark fiber (a fiber cable with nothing on it that a different company owns, and allows us to put whatever we want at each end) that gets us connected into a major IXP, this could be 100's of miles away. Once we are connected to this IXP we have two connections, one that is paid directly to a 'Tier 1' provider, but more importantly a connection on the 'exchange'. Once on the exchange we can set up 'peering agreements' with all of the major sources of traffic, Netflix, Google (YouTube), Amazon, Steam Etc. that allows them to send us traffic directly at no cost (other than getting to, and onto the exchange) since they also get to have that traffic bypass their ISP to get to us. Since most of the traffic comes from sources that allow this peering, we can get away with about 60-80% of our traffic coming from the exchange.",
"Each other, mostly. In concept, the Internet is just a collection of *inter*connected *net*works. ISPs are all hooked up to each other's networks, so every datacenter and PC in the world can talk to each other regardless of who their internet provider is.",
"short answer: from you long answer: ISPs don't create or provide internet. They provide you with a connection to the internet. That's what you pay for. But the internet is just a bunch of webpages created by people like you. The webpages are hosted by companies like \" URL_0 \" that are called hosting companies. They are also sometimes called \"Cloud companies\" or \"Servers\" depending on the service. But essentially those hosting companies are all doing the same thing, they are making sure your webpage is powered up and serving visitors. The web hosting companies also connect to the wider internet via the ISPs. Long long answer: The internet is just a bunch of inter connected computers. You can create an internet in your house with multiple computers (called an intranet). You can use one of those computers to create webpages that the other computer can see. Let's call the guy in your house that made the webpage 'Bob'. Now Bob wants to host other peoples webpages. So your neighbors pay Bob to use his computer to host the page. Bob's company is called a \"Server, cloud, or host\". ( URL_0 is the most famous hosting company). Anyone who wants a webpage can create one. They then pay Bob to serve (host) that page because they don't want to in their house and they don't want to keep their computer running 24/7 at home. Now Bob needs to make sure that your neighbors house is wired to his house so that he can actually feed the webpage to them. That is where Bob hires an ISP to connect the houses together with wires (fiber, cable, telephone, cat5, etc). The internet is all the different pages Bob is hosting and feeding to all the connected houses. The ISP (verizon, att, spectrum, etc) are just old fashioned wiring companies. They all evolved from telephone companies or cable TV companies.",
"Internet is weird. Companies put wires in the ground. But no one company could ever put a wire in the ground to all homes and businesses. Typically companies like ATT and Comcast have wires in the ground out to the customer. But those companies aren't \"the internet\". The wires to your home or business lead back to a POP. (point of presence). This is where all the ISPs hang out and exchange information. Kind of like an airport with different airlines shuffling traffic around. So you have a local carrier like ATT that all your friends an neighbors go through. And they end up going back to a POP. Where the traffic is then sent across the backbone of the internet. It might be ATTs network, or Comcast's, or Level 3, etc. Depends on the best route. There is a lot of co-dependence to make the internet work. Typically different internet providers lease circuits from other providers. That circuit is then a main point of entry into other providers networks. You might have Comcast, but Comcast has contracts for a 10GB circuit to ATT for the long haul traffic to certain subnets. In short. It's a giant fucking mess and depends on how many cables a particular company has in the ground. ISPs lease other ISPs cables all of the time. (and that's why I laugh when I read complaints about ISPs... alot of the time, people aren't even complaining about which ISP is actually responsible in reality...they just complain about the ISP that's charging them money..which is valid I guess.....but thoroughly hilarious when they threaten to change providers to ATT, when ATT was the problem all along)",
"There is no 'the internet'. There is no source that spews internet from the ground which some lucky party found and is now carefully distributing among the world. Instead, when two computers are connected via cable, they communicate without much effort. When a third one joins, it gets difficult to keep track of which device sent that message, and at what device it was directed. To manage this, there is this thing called a router that, much like a mailman in the old days, reviews every message that passes to see where it needs to go. Imagine billions of computers trying to do this all at once. Ain't gonna happen. So instead, a large collection of organised mailmen work together to make sure computer 107.283.476.23's message is successfully routed to computer 726.937.132.94, and so on. ISP's are these mailmen, and they put a pricetag on their services, because replacing equipment and managing communications isn't free. Voilà: a network of electronic mailmen that navigate billions of messages every second of the day, without a primary source or what have you.",
"The ISP is basically a big hub, where a bunch of computers are connected to the ISP’s servers. The internet is just a massive network. If you get on any part of the network, you can access any other part of the network. Connecting to an ISP gets you on the network (internet). From there, you can connect to every other computer on the network. I’m bad with analogies, but bear with me. Let’s say you wanted to meet a bunch of celebrities but have no way of doing that yourself. Then you hear Tom Hanks is willing to introduce you to a bunch of celebrities and it’ll cost you $100. So you give Tom $100 and he introduces or *connects* you to Justin Beaver, Carly Rae Jepsen, and other famous people.",
"ISP's provide their own network, and customers are connected to it. You can go directly to a service that uses the same ISP as you, without leaving your ISP's network. Since there are services that don't use the same ISP as you, ISP's connect their networks to each other at peering points in a few major world cities. There are also ISP-like connection companies that operate [tier 1 networks]( URL_0 ), and smaller ISPs often pay them for data transport to a peering point.",
"This question represents a fundamental misunderstanding many have about the internet. However, before I explain it, I'll give you a true ELI5: They get it from a bigger ISP that connects to other big ISPs, a bunch of smaller ISPs and data centers over a wider area than your local ISP does. Now to address the misunderstanding. To you, the consumer, the internet in a product that you buy. You pay a bill, and it comes out of a cable, into your router, and onto your computer. So, it's logical to see it as something that \"comes from somewhere\". However, that's not really what's going on. ISPs aren't *supplying internet*, they *are the internet*. You may not have the massive bandwidth that the likes of Google, Facebook and Amazon have, but unless your ISP is absolutely draconian, there's nothing stopping you from registering a domain, and hosting a site or a service directly from your home. 99% of people that connect to the internet are merely consumers, but even so, it really isn't a one way street from the sites you browse to your computer. Your public IP is just as accessible from anywhere in the world as the public IP of every major site out there if you choose to open up some ports. This isn't a huge misunderstanding, but it has some consequences. When people see the internet like something that comes out of a tap, they're willing to put up with a lot more crap from ISPs and regulatory agencies. If you see yourself consuming the internet like you consume cable TV, or even electricity, policies like fast lanes and data caps don't seem so bad. I remember trying to explain to my mother why it was crazy that ISPs were starting to put data caps on home broadband connections, and her response was \"Why shouldn't you pay more if you consume more?\" Well, because I don't want to pay for a certain amount of \"internet\", I want to pay for a connection to *the internet* to use however I please. However, if most consumers are fine with data capped plans, it stops making sense for ISPs to offer non-capped plans at reasonable prices, because they're generally less profitable. Also, net neutrality and stuff, but that's a little political for an ELI5."
],
"score": [
588,
242,
74,
13,
8,
7,
6,
5,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[
"GoDaddy.com"
],
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Tier_1_network"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
apt1if | How does a smartphone know the time after being switched on again without internet connection? | Technology | explainlikeimfive | {
"a_id": [
"egawhdn",
"egb44hm",
"egb0flq",
"egb4dod",
"egb5gfq",
"egbdpc2"
],
"text": [
"There's a small chip somewhere in the phone that keeps running even when the phone is off. It's just a clock, so it used an incredibly tiny amount of power.",
"In addition to the other correct answers that the phone has an internal clock, the phone gets time from the cell site even without an internet connection.",
"A clock that runs on the tiny tiny amounts of power (and sometimes a 2nd smaller battery) in your phone",
"The phone has either a small separate chip, or a tiny extra circuit inside one of its chips which is basically the same thing as a cheap digital watch - known as a Real Time Clock (RTC) and it's used purely to keep \"real\" time (in human terms) because computer chips use their own internal \"ticks\" which are millions of times faster and not necessarily synchronised with the \"wall clock\" time. That little RTC will run either from the phone's battery or perhaps a tiny extra battery or super-capacitor, using a tiny amount of power to keep time even if the phone is off. Often, the RTC can also have its own internal alarms, for example to wake the phone's main chip up every so often to check the network or similar.",
"Not many people know, but gps is also a great time provider.",
"Most hardware has an internal clock, oscillator, than can be used to keep time. Usually what happens when you phone gets access to a time server is it will latch the current time and then use the internal clock to increment the time. There is no reason to constantly query the time source if your oscillator only drifts 2-3 seconds over a 24 hours period. This is how your PC keeps time as well, the same hardware and logic is used."
],
"score": [
2002,
305,
160,
43,
27,
8
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aptsz0 | How does the YOLO algorithm perform detection? | Other than saying "An input image goes through a network and \*poof!\* objects will be detected." | Technology | explainlikeimfive | {
"a_id": [
"egb9sra"
],
"text": [
"As far as human understanding goes, there's not much more to it. Here's a dirty little secret - very few developers actually know how neural networks make their decisions. If you asked a developer what steps the process took to classify a dog or a bicycle, they'd have no idea - the answer is just \"it goes into a network and poof!\" For a more detailed explanation... The joke among developers is that neural networks, machine learning and all that is just fancy statistics. They're taking a ton of input data already matched with output data and trying to predict what the correct output data will be. Here, the input is a bunch of pixels and the output is a region corresponding to an object. Someone designed a slightly better neural network - a complex statistics machine for working out the \"rules\" that indicate objects. This one uses a \"breadth first approach\" where it looks at the big picture then zeroes in on stuff. Older ones used a \"depth first approach\" where they went through each area systematically. Breadth first allows it to take context into account, which is the key innovation."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
apukyt | Why are Graphic Cards that have been used for mining avoided? | I see used cards being advertised as 'not used for mining'. Is it just because of wear and tear? Do GPU's have a number of hours before they become redundant? | Technology | explainlikeimfive | {
"a_id": [
"egb878y",
"egbfbk3",
"egbo33p"
],
"text": [
"Because they have been used non stop and the hardware is usually worn down",
"This has been debated many times - If the cards are not physically damaged you really have no concerns when it comes to buying a card that was used in a mining rig. Run time on the cards really does not degrade their performance and temps are not a problem either as any modern card has thermal throttling built in, so without noticeable mods done to the cards there just is not a concern.",
"As some people have pointed out, there's a risk that the mining card was run super hard in order to milk as much output from it as possible. Many miners who operate large farms, or people who have really expensive electricity costs, might underclock their cards to maximize the efficiency of their cost to return ratio, and those are probably fine. But every miner selling their cards will say that they always kept them undervolted and with fan speed pegged at 60% in a climate controlled environment, because that's the only way anyone would consider buying their card. But I guarantee you that they were not all maintained like that. The problem is that it's impossible to tell which group your potential card came from. There's an inherent risk in buying a mining card that you might end up with one that was sitting in someone's shed just chugging away 24/7 for months. The other part of it is more a social consequence, I believe. For PC enthusiasts, basically an entire year worth of the market was completely destroyed because so many components, not even just GPUs, were prohibitively expensive because of mining. Some may argue to the contrary, but for many people there's a certain philosophical opposition. At least from many of the people I've talked to. Why would we get screwed over on pricing because of miners, let them make some money off of crypto for a bit, and then basically get their money back on selling the card off after they've got their use out of it?"
],
"score": [
6,
5,
5
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
apur3i | If we can simulate 3-dimensional objects on a 2-dimensional computer screen, why can’t we simulate what a 4-dimensional object would look like? | Technology | explainlikeimfive | {
"a_id": [
"egb9qc3",
"egbaoyn",
"egb9nxt",
"egbcmgn"
],
"text": [
"We can. If you google \"4-dimensional object\" you'll get some simulated versions, both as represented in 3D (real-life objects) and in 2D (computer images or animations). The problem is that humans do not experience 4 dimensions of space. Our brains are very very good at \"understanding\" 3D objects, so even a 2D drawing of one \"makes sense\" to us. Our brains are bad at \"understanding\" 4D objects, so it's hard to make sense of a 2D or 3D representation of one. One example which I think the brain is good at comprehending is the [Klein Bottle]( URL_0 ), sort of a 4D version of the Mobius Strip. If you imagine an ant walking along the surface of that bottle, it could go inside the opening at the bottom, follow the inside of neck around to get to the inside of the big chamber, then start climbing up the outside of the neck - by walking a straight line, it's flipped to the other side. The 4D part comes in where the neck intersects the big chamber. In a *real* 4D Klein Bottle, the neck doesn't touch the big chamber there. You have to imagine it being moved to the \"side\" along a 4th dimension of space - impossible in 3D, of course, but like a 2D drawing of a cube, you can kind of understand what the full object looks like.",
"URL_0 Matt Parker, a stand up mathematician does some very entertaining but very simple, as a former maths teacher, explanations and simulations of 4D space and objects",
"We can. It just doesnt look very logical especially if its just a picture. There are some animations that visualise this. A 4D \"cube\" for example basically a box where the sides are made out of other boxes and all sides of these are connected.",
"We can [a tesseract is one example.]( URL_0 )"
],
"score": [
101,
11,
7,
3
],
"text_urls": [
[
"https://images-na.ssl-images-amazon.com/images/I/41kA5VHqpbL.jpg"
],
[
"https://www.youtube.com/watch?v=1wAaI_6b9JE"
],
[],
[
"https://en.m.wikipedia.org/wiki/Tesseract"
]
]
} | [
"url"
] | [
"url"
] |
|
apusva | When in a pc game, how can I tell the sound I hear is from behind with a stereo headset? | Technology | explainlikeimfive | {
"a_id": [
"egbamkm"
],
"text": [
"While there are some ways your ear/brain can tell a sound is behind you (slightly muffled sound for instance), I don't think games simulate this. More likely, when you are playing a game you are constantly moving the camera, looking around. When you do so, the sound will get louder/appear sooner to one ear or the other, even just slightly and for a brief moment, giving you a cue as to where the sound is. In real life this is the most important tool we have for telling if a sound is in front or behind us (besides visual cues)."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
apvje7 | How come all digital screens use RBG (red, green and blue) pixels to make up images by creating different colours but when mixing paints to make different colours the primary colours are red, yellow and blue? Why is there a difference? | Technology | explainlikeimfive | {
"a_id": [
"egbgf84"
],
"text": [
"Red, Green, and Blue are the primary colors of light. Light is additive -- no light is black and all light is white. Magenta, Yellow, and Cyan are the primary colors of pigment. Pigment is subtractive - no pigment is white and all pigment is black. This is because pigment absorbs light (subtracts from available light), so essentially a black pigment would absorb all incoming colors of light and reflect nothing (or be black). Edit to actually answer question: Digital screens emit light, paint and other substances do not emit light so their color is based on what they absorb and reflect"
],
"score": [
15
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
apw0sb | How does a zip file take gigabytes worth of information and compress it down to megabytes? | Technology | explainlikeimfive | {
"a_id": [
"egbj3l5"
],
"text": [
"As it says in the second comment on the thread that prompted you to ask this question: > It's exploiting how compression works. Imagine you had data that was something like this: > 11999999855555555199999019995555555 > You could compress this down by just writing how many of each digit there are: > 21 69 18 85 11 59 10 11 39 75 > Two 1s, Six 9s, One 8, Eight 5s, One 1, Five 9s... and so on. > Now imagine you had data like this: > 7777777777777777777777777777777777777777777777777777777777777777777777 > You could compress it down to just this: > 707 > Seventy 7s. If that were something like several billion sevens, that could uncompress to something far larger than the compressed version. > This isn't exactly how the Zip Bomb works, but that's the general idea: use lots of repeating information that can easily be compressed way, way down. URL_0"
],
"score": [
3
],
"text_urls": [
[
"https://www.reddit.com/r/todayilearned/comments/apteiq/til_theres_a_zip_file_titled_42zip_its_known_as_a/egb0nzp"
]
]
} | [
"url"
] | [
"url"
] |
|
aq1ump | How is machine learning being used in business? | Technology | explainlikeimfive | {
"a_id": [
"egcvt96",
"egd0ck7",
"egd1wvu",
"egd1xsk"
],
"text": [
"Largely, it is being used badly. Unfortunately most of the decision makers don't understand the finer details of what inputs are required, and what the outputs mean - most managers (and I use the term like a four letter word) seem to be of the opinion \"I can buy one machine learning and my business will magically get better, and other businesses will think I am cool\" From personal experience right now, we (I work for a chemical processing company) are trialling a form of ML now, where a whole mess of information is being dumped into the system, from operating conditions(temperatures, pressures, flow rates etc), to maintenance routines, breakdowns, output rate and quality The \"hope\" is that we'll be able to let the system learn what combinations of operating conditions, outputs and the like contribute to equipment wear and tear, letting us extend or eliminate some of the more intrusive maintenance and providing something of a crystal ball for when the risk of failure increases (e.g. due to an over-pressure event)",
"As Dan Ariely said: \"Machine learning is like teenage sex. Everybody talks about it. Only some really know how to do it. Everyone thinks everyone else is doing it. So, everyone claims they’re doing it.\" The truth is to get to the state of using machine learning effectively, a sophisticated data infrastructure is required and thus there is a ramp up time while you build out the system. You also, generally, need a large amount of data to realize the value, which may add to that. Because of this, and other reasons that have been stated, the quote above is very applicable.",
"Poorly. There are a lot of things that *can* be done with it, but far fewer than people seem to think. Especially if you watch Microsoft’s commercials. The broadest example right now is probably ad personalization. After that, probably shopping recommendations. Then maybe Gmail auto replies, I guess. You can see where this is going. Everyone interacts with features of Apple or Google or Facebook products every day which are heavily based on machine learning. In a sense, someone using their phone to take a picture of a whiteboard is using machine learning for business. That’s probably not what you meant, but it’s closest to the daily reality right now. Practically speaking, no one has a clue what to do with ML, and even fewer people can even correctly define it. Knowledge will catch up and we’ll see people starting to do creative things, but it takes a while for something this complex and this riddled with misinformation and marketing lies. Honestly, you personally probably use machine learning an order of magnitude more than almost any company at this point.",
"It's an untapped and very nascent technology. It's being used in business but all of the infrastructure of tools, frameworks, knowledge, and middleware don't really exist in a way that is easily consumable by your average every day business-- yet. But it's coming. I liken this era of ML to the early days of the world wide web (not the internet as a whole). Back in the early 1990s , there were few websites and even fewer businesses hosting them. People saw the potential, but the infrastructure wasn't quite there (for one, most people either had dial-up internet access or none at all). Of course it took a few years, but over time everything caught up and the web is ubiquitous and mission critical for most businesses. ML (aka AI) will get there, but we're not there yet. Right now, pretty much the only people who understand how to use it and apply it properly are academics and researchers. But efforts are being made to go beyond this. Entire companies are being formed around harnessing the unique and powerful capabilities that ML can provide. The big players like Amazon, Microsoft, Google, Facebook are investing billions of dollars into it. They all know (or are at least placing heavy bets) that it will be as ubiquitous as the Web was in the 90s and beyond, and the \"Cloud\" was in the 2000s and beyond. To completely address the question, if you have ever used a remote deposit app to take a photo of a check and it magically gets added to your bank account, you likely used ML software that handles handwritten digit recognition. This is like one of the most \"basic\" applications of ML, and that's why you see it used commonly today. Without ML, you can't do this reliably at all. If you have done a reverse image search on Google or Bing, you used an application of ML to identify similar images. (ML is extremely good for image processing/recognition). If you've used an app that takes a photo of a dog and it tells you what kind of dog it is, that's ML at work as well. These are examples of ML-based tech that is understood and generally reliable (though never perfect). There are many other examples of ML being used by businesses today (usually BIG businesses like oil companies, tech companies, etc.. but they are custom solutions that are in their very early stages of being understood and applied). In the near future, more and more discoveries will be made, more tools and frameworks will exist, and more people will understand how and why machine learning works, and most importantly how to take advantage of it."
],
"score": [
16,
11,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aq1y0a | Photography shutter speed, iso and aperture. | Getting more into photography and i want to stop using auto. What does each one do, how and when should i adjust them and what is good to use for day time and night time photography. | Technology | explainlikeimfive | {
"a_id": [
"egd0huk",
"egcx0ba",
"egcwn7s",
"egd4968",
"egd0cgt",
"egczb20",
"egcwhk4",
"egdgugs",
"egdbpqr",
"egdgkd7",
"egd5i5v",
"egd6iqt"
],
"text": [
"[This cheat sheet]( URL_0 ) is a good very brief overview of what all the settings are. The basic idea is this: you want an image that is bright enough to see clearly, but not so bright that it's all white. You have three knobs to control how much brightness you get. Each affects the picture differently. Shutter Speed: Shorter times (like 1/2000) get you very little light, and longer times (like 30s) get you lots of light. Shorter times also freeze action (because you're only gathering light over a very very short period, so nothing has time to move. Longer times produce blur in anything that moves *even a tiny bit*. Anything much longer than about 1/10th - 1/30th of a second, and you won't be able to hold the camera steady enough without aid (such as a tripod). Sensitivity (ISO): Lower numbers (like 100) mean less sensitivity, which means less brightness. Higher numbers (like 6400) mean higher sensitivity, which means more brightness. This is like boosting the gain on a microphone. The more you turn it up, the more noise you get in your result. Your image will look more \"grainy\" the higher you turn ISO. It'll look like static is partially superimposed on your image. Aperture (f-stop): Lower numbers (like f/1.8) mean a wider opening and more brightness. Higher numbers (like f/16) mean a narrow opening and less brightness. Lower numbers (bigger opening) also allow more light that's coming in at odd angles, which will decrease how much of the image is in sharp focus (also called a \"shallow depth-of-field\"). Higher numbers (smaller opening) will cause more of the image to be in focus together. That cool \"portrait mode\" thing that all the new phones do with their multiple cameras is simulating the effect of a wide aperture (low number) -- where the subject is in focus and everything else is a creamy blur. You pretty much always want an image whose brightest points are almost-but-not-quite 100% white, and whose darkest points are almost-but-not-quite 100% black. You can play with these three adjustments in different ratios in order to achieve that, but you'll get a very different image depending on how you combine them. That's the artistic part!",
"Taking a picture is like filling up a bucket of water. The shutter speed is how long you keep the hose on. The aperture is how big the hose is. And the ISO controls how big your bucket is. You don't want to overflow your bucket (over-exposed image) and you don't want to fill it too little (under-exposes image). You want to fill it about halfway. So if you have a big hose (wide aperture) you need a bigger bucket (lower ISO) and/or only turn the hose on for a short time (faster shutter speed) in order to get the bucket filled just the right amount. Similarly, if you have a small hose (narrow aperture) you might have to run the hose for a long time (slow shutter speed), or use a smaller bucket (higher ISO). -- Each of these decisions has trade offs in how the picture will turn out, but I don't know how to describe them as ELI5. Also, setting those values depends on available light, which doesn't really fit the analogy. The analogy works best if you assume you have constant lighting conditions, then figuring out what the settings should be can be done with some trial and error, which helps solidify the concepts.",
"ISO refers to a standard (ISO 5800:2001) of how fast film responds to light. Digital cameras also rate their sensors using an equivalent system since that's what everybody knows. Aperture is the size of the opening in the lens. A bigger opening lets in more light. Shutter speed is the amount of time the shutter is open letting light hit the film/sensor. You need to adjust all 3 of these so that your photo is properly exposed. You probably want to start at ISO 100. Next you set your aperture or shutter speed based on the effect you want. If your shutter is open too long, anything that moves will be blurry. Maybe you want this if you want a bit of motion blur. If you want a crisp image then you want a fast shutter speed. The bigger the aperture (which is actually a smaller number i.e. 2.8 is bigger aperture than 4) means less of your image will be in focus. Tiny aperture means everything in focus. Landscapes you probably want everything in focus. Portraits you probably want face in focus, everything else blurry. Once you know the range you want your shutter speed and aperture, if you can't get photo exposed properly, then it's time to change your ISO. After auto, you probably want to try shutter priority or aperture priority mode. They will let you pick one of shutter or aperture which automatically adjusting the other of shutter or aperture to properly expose the photo. If it can't do it, you may need to manually change ISO. Higher (faster) ISO has more grain / noise than lower ISO, so you want to use lowest ISO possible.",
"It seems that other users have covered shutter speed and aperture pretty well, so allow me to go into a little detail on ISO Back when we used film, the film was covered in tiny grains of crystals which harden when exposed to light. If they dont get enough light to harden, they washed away when developed (blacks/underexposed), resulting in a clear portion of film. If they get too much light, they harden completely and cannot harden any more (washed out whites/overexposed). Hardened crystals do not wash away in the development process, resulting in an opaque portion of film A bigger ISO number = a bigger crystal size. A bigger crystal is able to absorb more light (because they have a larger surface area), and so it needs less of it to become \"Exposed\". However, the bigger crystals were more visible to the naked eye and made the images look grainy/noisy. In digital photography, the crystals were replaced with pixels. The pixels dont get any bigger or smaller when you adjust the ISO, instead the image processor inside the camera takes the value of the output from the pixel and amplifies it. A photo with an ISO of 100 has its pixels amplified 100% more by the camera's image processor than a photo taken at ISO 50. This would be fine and dandy, but electronic components do a funny thing when they have electricity run through them: they heat up. Not every pixel is created equally and one pixel might heat up more than its neighbors. As a pixel heats up, it becomes more and more sensitive to the light hitting it, resulting in a stronger signal which is then passed to the image processor. When the processor amplifies the signal, the already over-sensitive pixel is amplified even more. This is the digital noise created in high-ISO digital photography. Because of this noise, if you are trying to produce the cleanest image possible, you want to use the lowest ISO possible. This is not a golden rule however, as the aperture and shutter speed also come into play. Film grain and digital noise are not the exact same thing, but they work in similar ways. This isnt a complete answer, but I hope it helped you understand the basics.",
"Pretty much everyone has given a good explanation of what the different parts mean, so just going to add this in as an extra tip. One of the biggest changing points of my photography was learning about exposure. It took me way to long to learn that there’s a little meter that tells you how exposed a photo is going to be, and it saves you a hell of a lot of time taking photos and seeing if it’s what you want. Find the exposure/light meter for your camera (google if you don’t know what it looks like) and it’ll help momentously. Once you’ve found that, it’s much easier to fiddle with the other settings to get the look you want. Best of luck!",
"Shutter speed is how long the shutter stays open, exposing the film or sensor to the light. Since it's a fraction, the bigger the number (only the denominator changes generally) the shorter the exposure and the less light hits the film/sensor. So that's a bit counterintuitive. 1/60th is half the light of 1/30th as an example. Aperture is how big the adjustable hole is, behind the lens, but in front of the film or sensor. Sadly, the bigger the number, the smaller the hole, and the less light. So that's a bit counterintuitive. Let's ignore ISO for a minute. For most of the time, and most of the situations the shutter speed and aperture are on a see-saw. If you increase the shutter speed (less light) you have to increase the aperture size to compensate. So it's very likely your camera has ten different (or a 1,000 different) combinations of shutter speed and aperture that give just the right amount of light to the film. But, even though the total light entering is the same, the effects on the picture are NOT the same. Examples: 1. A fast shutter speed (not much light) combined with a wide open aperture (a lot of light to compensate) will be great at capturing a sports shot with a lot of action, and minimize blur. Sounds great right? It also gives you a very narrow depth of field, so you have to be damn sure the camera is focused right on what you want to be sharp. Otherwise it will be out of focus. And what if you want the action to be blurry, like a waterfall. Well, then this combo sucks. 2. A very slow shutter speed (like a whole second or two, gobs of light) combined with a very small aperture (to make your film happy with the total light. You didn't forget about the see saw right?) will allow the the water to be blurred by the motion over time, but allow the not moving bits like rocks and trees to be nice and clear. Awesome! Oh yeah, won't work without a tripod. the camera can't move AT ALL for two whole seconds. But the tiny aperture gives you fantastic depth of field, so your camera will capture everything from two feet to infinity with beautiful clarity. ISO or film speed describes how sensitive the sensor or film is to a given amount of light. So some film was designed to be super sensitive to light so you can take pictures without a flash, even though the room or whatever is not super bright. Let's say it's ISO 800. That's pretty sensitive to even small amounts of light. A typical use case would be getting good indoor photos at night (no sun) and no real bright lights or flash is allowed. A \"fast\" ISO let's you get nicely exposed photos, even though there's not much light. Great! yeah, but it doesn't capture detail as well as the lower ISO ratings. But without the \"Fast\" ISO sensor setting, even with your slowest reasonable shutter speed (to get more light) and your biggest aperture (more light) there *still wouldn't be enough light* to get a good exposure. All your pictures would look dark, and there would be no detail at all in the shadows. & #x200B; To me, the best way to think about, is to think about what you want to achieve first. example: there's this famous picture of the Queen inspecting the troops, a whole row of them. If you use your point and shoot on Auto, since it's outdoors, it will pick a smallish aperture (because you have gobs of light outside) and a fastish shutter speed to pretty much guarantee you don't get a blurry pic from camera shake, and everything will be crispy sharp because of the tremendous depth of field from the small aperture. Oh........but the photographer didn't want that. They wanted it to be totally obvious who was the whole point of the photo. The wanted a very narrow depth of field so the Queen was is great focus, and all the soldiers in the line behind her and ahead of her, were all blurry. That makes sense. How do we do that? We don't want or need a small aperture, we need the biggest aperture we have. Small hole = pinhole effect = verry deep depth of field. Big hole = very narrow depth of field. Ok, got it. So we open the aperture up wide open (giving us gobs of light, which we don't really need since we're outdoors anyway) so we have to compensate with a super short exposure length, like 1/2,000th of a second. Even then, it might not be enough so reduce the total light down to where the film or sensor is happiest. Then we need a film or ISO setting that makes the sensor *less* sensitive, because we have this huge excess of light, because we *have to have* the big aperture to get the effect we want. [ URL_0 ]( URL_0 ) & #x200B; Once you decide what you want the effect to be, then you can look up how to get it. Here's the cheat sheet to know what you must have, and then you arrange the other two things to suit that: blurred motion, must have slower shutter speed. Anything below 1/30th of a second, you pretty much have to have a tripod. Sharp motion, must have \"faster\" shutter speed to \"freeze\" the action. 1/400th will do pretty good, 1/1000th, or even 1/2000th, even better at freezing the action. Good exposure in dim lighting, must have longer shutter speed AND likely a bigger aperture to make use of low light. If that's not enough, then add higher iso value too. Big depth of field, must have small aperture. Tiny depth of field must have big aperture. used to be a photographer and journalist 100 years ago. Ended up being an eye doctor it was so interesting.",
"Shutter speed is how quickly the shutter remains open, letting in light (typically displayed in fractions of a second, but can be in whole seconds as well). Aperture is the amount of light that is let in. If you have a faster shutter speed, you need more light, which means a higher aperture (represented in f-stops or t-stops, which are mathematical representations of the light transmission). ISO was originally the \"speed\" of the film. It is the chemical makeup that affected how the chemicals in the film absorbed light. \"Faster\" speed film has a higher ISO, and is more sensitive to light. It needs less light to activate the chemicals in the film (the drawback to this is it produces a more grain literally more visible grain in the film). ISO in digital cameras obviously don't use chemicals, but the sensor attempts to react the same way as film speed does; i.e. faster ISO means less light needed, at the trade-off of more \"grain.\" Faster shutter speeds can catch movement with less blur, but again need more light. Higher aperture lets in more light, but gives you a deeper depth of field (more stuff in focus), so it's not great if you want to artistically have less things in focus. Higher film speed lets in more light, but gives a grainier, less clear image. The trick is to find a balance between all three that gives you the image that you want.",
"Think of your eye as a camera. Eyelid is the shutter, iris aperture and ISO is sensitivity to light. Now close your eyes, open them for one second and close them again. You just took a photo with the exposure of 1 second. You eyelid controlled how long the photo was exposed, your iris controlled how much of light got through and the rods and cones your retina controlled how sensitive your eyes were for the light. In photography terms your eyes are always on Tv (time value) mode, since sensitivity and aperture is controlled automatically.",
"To try and avoid any elaborate analogies and give you the couple of quick rules I work from... Aperture controls the depth of field - how much is in focus in front and behind of the point you focus on. Wider apertures (low f numbers) means less stays in focus. Shutter speed controls how the camera records movement (both your subjects moving and the hand holding the camera). Faster shutter speeds freeze movement, slower shutter speeds blur it. Iso controls how quickly the camera reacts to light - higher numbers means the camera works quicker (good in lower lighting conditions) but also the higher the number, the more noise will appear. The technical side of photography is learning to juggle these sensibly - because each setting affects how much light hits the sensor, you have to prioritise which are important for the photo you are taking and balance them. Taking a landscape, you want high quality and lots in focus, so a narrow aperture and low iso would be ideal - this means a slow shutter speed and perhaps using a tripod. Shooting handheld in low light means a high iso and wide aperture are needed to allow a fast enough shutter speed to stop blur.",
"Most people talk about the \"exposure triangle\", but this leaves the available light out of the equotation. \"Exposure square\" would be the better word, because in fact you have four factors: Exposure time (how long will light hit the sensor?), aperture (how much light will hit the sensor?), ISO (how much will the signal on the sensor be electronically amplified?) and the available light (cloudy or sunny, shade or direct sunlight etc?). If one of these factors is reduced by 50% (1/100 second exposure time instead of 1/50, ISO100 instead of ISO200, aperture 4 instead of 2.8 or cloudy instead of sunny weather) you will need to double another factor in order to get the same exposure. Easy, eh?",
"People with dark skin need a lot of sun exposure to get sunburn, while people with pale skin need a lot less. This is like ISO - you’re changing how sensitive your camera is to light. If you’re trying to get a tan and there’s not much sun, you’re better off being pale, but If there’s too much sun then you’ll burn (or in your cameras case, be overexposed). Likewise if you have dark skin and there’s not much sun then you won’t tan at all (underexposed). Find the lowest ISO you can use after picking your other settings - start low and bump it up until you’re happy. High ISO means more sensitivity and also happens to add graininess. Aperture is more like how your eyes get bigger at night to let more light in, then smaller when you turn the bathroom light on and more light is around. Changing this also happens to affect your “focal length”. A smaller number means the camera eye is more open, there will be more light entering and things in background will also be less in focus. A larger number means it’s less open, so less light is entering and things will be in focus both in the foreground and increasingly so in the background. Imagine having your eyes closed and opening them for a set amount of time before closing them again. If you open them really really fast, you’ve let hardly any light into your eyes so you won’t see much. Open them for a full second and much more light has entered your eye to help you see. This is like shutter speed. Shutter speed is like taking an awesome snapshot of a moment in time - if everything is really still you can use many tenths of a second or even seconds to capture the light around you for a single picture. This is how we can take pictures of things like the Milky Way - the light is there but we need to capture many seconds worth of it for a camera to see it. If there’s movement though, things will be blurry. Figure out the best shutter speed by thinking about movement in your picture; eventually you’ll develop a feel for what you need to use here, as with the others.",
"Oh the holy trinity of exposure. So our eyes do a phenomenal job of properly exposing scenes in our day to day life. Rarely are we sitting there thinking “it’s too bright” or “it’s too dark”. Our eyes have a lot of dynamic range, meaning we can see very well in shadows and in bright areas in the same scenes. Cameras have a much smaller range where things look ok. There is no “proper” exposure, you need to decide how bright or dark to make a photograph. There are three mechanisms that you can use to change the brightness, and each one has its own side effect. Changing any one changes how bright but it will inherently have a side effect, so you want to change which one to adjust based on what effect you want (or want to avoid). Aperture is like the iris of your eye. It changes exposure by making the iris in the lens bigger or smaller (so yes aperture is dependent on your lens). The side effect is the bigger the opening, the fewer things will be in focus. The amount of things in focus is called depth of field and having a “shallow” depth of field can be a desired effect, often a result of a high end, expensive lens. Adversely sometimes you want as much in focus as possible, but stopping down the aperture to be a small opening will make the picture darker. Shutter speed is how long the camera is taking the picture. The longer it’s exposing the sensor (or film) to the world, the brighter the picture. Of course the side effect is being able to stop time or show motion. With a fast shutter speed you can stop motion like a drop of water or with a slow shutter speed you can show motion like the streak of a car driving by. Don’t confuse motion blur with focus. Motion blur has “streaks” showing the motion. ISO is how sensitive your sensor (or film) is to light. The more sensitive, the brighter the image, the less sensitive the darker. The side effect is increased noise or grain as the ISO increases. It’s generally considered desirable to shoot with the lowest ISO setting possible. The ISO is kind of the last thing you want to change when you’re out of options in your other two, however these days, cameras are getting remarkably good at shooting with high ISO and not having it be a big deal. But back in the day you had to change FILM to change ISO 🙀 Hope this helps!"
],
"score": [
4024,
637,
136,
127,
42,
16,
15,
5,
4,
3,
3,
3
],
"text_urls": [
[
"https://imgur.com/a/APq2590"
],
[],
[],
[],
[],
[
"https://ca.hellomagazine.com/imagenes/royalty/2015020623277/queen-celebrates-63-years-on-throne/0-121-226/queen2--z.jpg"
],
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
aq41m4 | How did Shareware as a distribution model for old computer games (Doom, Jazz Jackrabbit) work before the internet? | I know that you get a crippled version of the game on disc, but how did you actually get access to the full game? And how would you get hold of the Shareware version in the first place if the game was not in retail stores? | Technology | explainlikeimfive | {
"a_id": [
"egda9sf",
"egda8ic",
"egdaj2p"
],
"text": [
"Well, this is a fun surprise to see posted. I am actually one of the inventors of the \"try-then-pay-if-you-want\" shareware model, back in the 1980s. About five or ten people came up with the idea around the same time. & #x200B; At first, people would download shareware via telephone-based modems, which were very slow. A download could take 5 to 90 minutes, despite the small size of programs back then. A server was a PC operated by a hobbyist, and most could only accept one caller at a time! & #x200B; After a while, some small companies offered shareware by mail: they would literally mail you a floppy disk containing a copy of anything they had in their library. & #x200B; & #x200B; & #x200B;",
"When my mum bought me Doom 2, she sent a cheque in the mail and they sent back the game and a cool TShirt. The shareware of Doom1 could be easily copied on floppy disc or was provided with PC magazines",
"Discs, and disks through the mail and magazines, some times free. People would copy the data on there own floppy disks and give them to friends. That's where the term \"share ware\" came from. Jazz jackrabbit has a very famous share ware version and doom became popular because the whole game was technically share ware."
],
"score": [
13,
5,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
aq5mpr | How do ZIP files work and what are they best suited for? | Technology | explainlikeimfive | {
"a_id": [
"egdirzl"
],
"text": [
"Say you have a book, and you want to compress it. Now look for repeated words or phrases, and replace them with a code, and store a dictionary of codes. So if the book says \"hello world\" 10 times, instead replace it with \"XYZ\" and make a note of it. So you now have a book with way less letters, and a list of codes that you can look at to get back to the full book. Works best for things that aren't already compressed, or if you simply want to send a bunch of files in one go."
],
"score": [
10
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aq7xxh | What are the differences between RealD 3D, Imax 3D, and Dolby Cinema 3D? | From memory (like 8 years ago memory) I don't like RealD 3D, I never tried Imax 3D, and from recent memory I really like Dolby Cinema 3D. Honestly I only really care about the difference between dolby 3D and Imax 3D | Technology | explainlikeimfive | {
"a_id": [
"ege7js3",
"ege6aqz"
],
"text": [
"ah, brushing up before watching *Alita: Battle Angel*?",
"Imax 3d is big format film (thus imax). Dolby cinema 3d uses Dolbys audio for the 3d movie. RealD I think is regular 3d. This is a bit from wiki. \"RealD 3D cinema technology is a polarized 3D systemthat uses circularly polarized light to produce stereoscopic image projection. The advantage of circular polarization over linear polarization is that viewers are able to tilt their head and look about the theater naturally without seeing double or darkened images.However, as with other systems, any significant head tilt will result in incorrect parallax and prevent the brain from correctly fusing the stereoscopic images.\""
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
aq9cvu | How and why did we start eating cooked food? | Why does cooked food even taste better than raw if raw food is what we started out with, and that's what every other species eats? | Technology | explainlikeimfive | {
"a_id": [
"egeb7kf"
],
"text": [
"Burning food kills bugs and parasites that might be inside and reduces the likelihood of getting sick from eating it. Burning food also turns the proteins in food into a gel-like substance making it easier for the food item to keep said proteins allowing the consumer to get more calories from the food. This mattered more when we had to hunt and farm our own food as sources were limited by your effort so getting the most out of a meal was the name of the original perma-death open world survival game."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
aqd9wp | How does the camera follow the bullet or tank shell in those videos of them in flight? | Just watched [this gif]( URL_0 ). The shell is travelling so fast there's a shock wave. How does the camera keep the framing so perfect at that speed? | Technology | explainlikeimfive | {
"a_id": [
"egf62ur",
"egf6c8e",
"egfnx1o"
],
"text": [
"Usually they use a rotating mirror that precisely matches the expected speed of the object. Because it sweeps out a large arc the mirror doesn't need to spin unreasonably fast.",
"The people who shot that video knew exactly what was going to happen. They probably made several trials to get the settings exactly right. You only saw the best take. [Check out the Slo Mo Guys]( URL_0 ), they sometimes include out-takes where you can see what happens if you make a little booboo and record it at super slo mo.",
"As someone else already said, they use an elaborate setup with the camera filming a mirror which is reflecting the image. The mirror/camera setup rotates while it films. The camera isn't tracking the moving object, the mirror is. This is really hard to grasp by simply reading how it's done, it's really better to see it for yourself with [this]( URL_0 ) video. It's fascinating, and the Curious Droid channel that made it does an excellent job of explaining things perfectly so it's basically an ELI5 video. Highly recommend watching it"
],
"score": [
8,
3,
3
],
"text_urls": [
[],
[
"https://www.youtube.com/channel/UCUK0HBIBWgM2c4vsPhkYY4w"
],
[
"https://youtu.be/vluzeaVvpU0"
]
]
} | [
"url"
] | [
"url"
] |
aqe8bx | What is the difference mechanically between copying a file and moving it? | I was wondering if there's is really a difference. Depending on the difference, that could mean transferring consciousnesses would be possible without the problem of there just being a copy of you and the original you is dead. | Technology | explainlikeimfive | {
"a_id": [
"egfd8hk"
],
"text": [
"Copy is to make a copy of the selected file or folder and place the duplicate in another drive or folder, while move is to move the original files from one place to another location. The move command deletes the original files, while copy retains them."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
aqk7x0 | How can racing games that run at 60fps have timers that give times with milliseconds of difference, when one frame is 16-17 milliseconds? | I've been looking at world records for racing games like Mario Kart, and people are shaving off just a few milliseconds of time quite a lot. How is this possible? | Technology | explainlikeimfive | {
"a_id": [
"egghxi6",
"eggjl35",
"eggjckq",
"eggwznp",
"eggm7gy",
"eggrk29"
],
"text": [
"The framerate only tells you how often the screen updates, the cpu might have a clockspeed much higher than that, it is entirely possible to simulate the last half a second per millisecond to calculate the actual time in miliseconds",
"The image updates at 60 fps, but the physics may be updating more frequently than that. A common technique is to do multiple physics updates per frame. So maybe it does 5 per frame, each one being logically about 3ms apart. That means it works out 5 \"snapshots\" of where each object has been throughout the frame. Another way it could do it is interpolate based on the object's speed. If it detects the car has crossed the finish line this frame, it can work out the precise time it hit it based on its previous position, its current position and its speed. These two techniques could be used together for more accuracy.",
"The refresh rate only tells the story of the graphics that appear on your screen. The underlying program still runs in real-time to perform all the calculations needed -- importantly the physics, which would appear absurd chunked into such slow intervals.",
"At the exact frame the car enters the finish zone, you have a positive, typically non-zero, distance from the finish line to the front bumper. By dividing this \"overshoot\" distance by the current speed, you know approximately how long it took to overshoot the finish line (assuming constant acceleration). Subtract that from the current time to get an estimate of the exact time the front bumper touched the finish line. The other answers about running physics hundreds of times per second are totally wrong. If anything, physics usually runs *slower* than graphics--30hz is not uncommon--and values are just interpolated.",
"The reason is that the console doesn't always manage to calculate the next frame in time, causing a slight dip in frame rate. So two players might finish the game in the exact same amount of frames, but one avoided scenes where the console had to do a lot of work to render the graphics and therefore got a few ms lower time on the clock. You might have seen Golden Eye or Perfect Dark speedruns (N64 games), where they keep looking at the floor - that is because this gives them a faster frame rate, resulting in much better times.",
"Another way besides running the physics tick rate much faster than the graphics framerate, that is slightly less accurate, but a lot more computationally efficient, is interpolation. Say at 4:37 and 39 ticks, the car is 0.4 m behind the finish line, and at 4:37 and 40 ticks, it is 0.6 m ahead of the finish line. That means that it most likely actually crossed the finish line at 4:37 and 40.4 ticks (which, if physics runs at 60 tps, is 4:37.673, rounded to the nearest millisecond)."
],
"score": [
89,
34,
13,
6,
5,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
aqks9z | Why was the atomic bomb worse than mass carpet bombings in WWII? | Technology | explainlikeimfive | {
"a_id": [
"eggm4iu",
"eggmmc8",
"eggmslt",
"eggmgrp",
"eggnils"
],
"text": [
"There’s a great video about this by a youtube channel called Knowing Better, I’d really recommend it. It’s a video called “How to Make Bad History Worse.” It’s not only about the atomic bomb but it will answer your question. Edit: actually it’s the very first thing he talks about in the video now that I went back and watched it.",
"It wasn't, and it didn't end the war. The atom bombs weren't even the most destructive, as you said. Documents show they met about it and decided it changed nothing. At the time, they just wanted to hold out long enough for more favorable surrender conditions (they knew they already lost). They wanted to do it by either forcing the US to invade, thus inflicting so high of casualties with their heavily defended islands that the US would have to settle, or convincing the USSR (who was neutral at this time) to mediate negotiations and convince the US to give them their preferred surrender conditions. Then the USSR invaded them from mainland Asia. This royally fucked all their plans and forced them to immediately surrender.",
"The psychological impact of the city where you grew up (and what's almost everyone you know) disappearing in a fraction of a second is what sticks with people. With the carpet bombings, you kind of have warnings, you can get to safety and ride it out. Yes many people died and they were devastating but there's some semblance of control of your own safety. & #x200B; The nuclear bomb was never seen before, it came out of nowhere and annihilated a city. Not to mention the affects on the body are insane. There are stories of people wearing thin cloths where the skin that was covered was completely untouched and everything exposed was burnt to the bone. There's one story of a survivor who was in the washroom when the bomb hit, it leveled her home but she survivors relatively unhurt. Her sister was standing outside and was completely disfigured and died days later.",
"Well think of how it looked to Japan. It was a show of force, probably the most frightening thing anyone in the world had ever seen. A nuclear bomb is terrifying. The US demonstrated that not only would they bomb japan, but that they had bombs capable of vaporizing entire cities instantly, along with hundreds of thousands of lives gone in a flash, with ONE bomb. Imagine if you were Japan. Your enemy can literally choose any day of the week to blow up one of your cities, and there’s nothing you can do about it whatsoever. It’s not so much that the nuke is “worse” than carpet bombing or caused more damage overall. It’s that a world superpower had bombs capable of leveling cities within seconds, and said superpower demonstrated not once but twice that it will use those bombs on any city in Japan if it wants to, unless Japan surrenders.",
"During a normal carpet bombing raid you would have hundreds of airplanes flying over an area dropping tons of bombs. This required a strong supply line with lots of US factories, ships and crew tied up in order to conduct a single bombing raid. And during the raid they would be subject to flak and interceptors. The targets also got warnings of the incoming formation of aircraft and could seek shelter. & #x200B; However in Hiroshima, a single aircraft, like many other American aircraft flying over the city that day, did not trigger any warning system and were not shot at. It dropped one bomb and leveled the entire city. Another day, another bomber, another city, no warning, nothing they could do about it. How many days, how many cities, until the Japanese people could offer no more resistance? & #x200B; Of course what Japan did not know was that the US were out of supplies to make bombs out of. And they would require huge facilities to even produce a bomb every month. However the US claimed that they had hundreds of bombs prepared and could keep on dropping them until the surrender. And there were nothing Japan could do about it."
],
"score": [
10,
5,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aqkwmk | How was the Opportunity Rover able to have last words? | Technology | explainlikeimfive | {
"a_id": [
"eggnjip",
"eggnfao",
"eggndxu",
"eggoc39"
],
"text": [
"Programmers choose the text for error messages all the time. When the logic is added to detect this situation, and send an error, the choice of messages was made. Programmers are deeply, deeply in love with the cryptic and poetic when it comes to messages that might never be seen.",
"What that means is that the last message Opportunity sent back probably consisted of status reports indicating low battery voltage and low voltage from the solar panels, indicating inefficiency due to the global dust storm that covered them. We, as humans, interpreted the message and anthropomorphized it, because that's what humans do. Godspeed, *Opportunity.*",
"The rover didn't literally say \"my battery is running low and it's getting dark.\" That is the human interpretation of the message. You ask \"did the scientists notice it was about to die?\" and the answer is yes, and they know that based on the information the rover sends back to them. The last piece of information we got from it was its battery status and light levels which translated into \"my battery is running low and it's getting dark.\"",
"The rover sent back regular status updates every day. Things like battery voltage, power consumption, power production, temperatures, component status, etc. These status updates helps the engineers determine its state so that they might send commands to improve its condition. For example to not drive as far but to instead drive to a slope where it might get a better angle for its solar panels. The last message that Oppertunity sent were such a status message where part of the status was that the battery levels were running critically low and that there were very little power generated from the solar panels. This was then poetically translated into English as \"My battery is running low and it's getting dark\". It rolls off the tung a bit better then 0034862054 or whatever it actually sent."
],
"score": [
11,
7,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aqm515 | How do one-way mirrors work? | Technology | explainlikeimfive | {
"a_id": [
"eggxnv0"
],
"text": [
"Contrary to their name, there's actually nothing \"one-way\" about one-way mirrors. In the interrogation room, it's kept very very bright so that the glass acts a mirror and all the criminal can see is their own reflection. But on the other side, where the cops are, it's kept quite a bit darker so the light shines through and they can see into the interrogation room. If both sides were kept equally well-lit, the \"mirror\" would function as an ordinary window for all parties. [Here's a HowStuffWorks video]( URL_0 ) demonstrating this concept at work. Additionally, you can try this for yourself at home quite easily. Late at night, go look out a window. There's a good chance that you'll see only your reflection. Conversely, during the middle of the day, when it's bright and sunny out, you probably won't see your reflection and you'll be able to see the outside world."
],
"score": [
9
],
"text_urls": [
[
"https://www.youtube.com/watch?v=4kKL32opewI"
]
]
} | [
"url"
] | [
"url"
] |
|
aqmftp | [Networking/Computer Science] Does an online streaming video with static background images (like a slideshow presentation) consume less data than an actual video of the same resolution/quality and length? | Does the video still download each frame as an individual image or can it repeat use of an image in a previous frame in the case of a slideshow? For example, would the following use the same amount of data? * 10:00 long YouTube 1080p 30fps slideshow presentation with HQ audio * 10:00 long 1080p 30fps video of PewDiePie's Meme Review also with HQ audio. Also, subscribe to PewDiePie on YouTube! | Technology | explainlikeimfive | {
"a_id": [
"eggzno4",
"egh0ht9"
],
"text": [
"depends on the codec. But yes this is a thing, the codec uses some \"vector math\" to try to save as much as possible! Pretty much every codec online does that youtube twitch etc...",
"Many modern video file formats don't actually store the images for each frame. Instead they save the difference between the last frame. So if you'd have a black screen and then one frame later you turn one pixel to white, only that pixel would be stored and send. So unless you're going through your slideshow at 30 fps for 10 minutes, your slideshow is better in terms of resources."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
aqmsgy | How Rover Opportunity lasted 15 years when the mission was planned for only 90 days? | Technology | explainlikeimfive | {
"a_id": [
"egh2q0s",
"egh29eb",
"eghj3b6"
],
"text": [
"They originally thought that dust would build up in the solar arrays and prevent it from getting enough power (which is actually what happened to Opportunity in the end). They didn't know that the wind on Mars would do such a good job of clearing out the dust, which allowed the solar panels to continue functioning.",
"It didn't have a gas tank or anything else that could run out. It has batteries and a solar panel. It was thought that dust would build up and eventually the solar panels would lose so much efficiency that they would stop being able to charge rovers; wind actually seems to have blown away more dust than expected leading to less build up over time The rovers were rugged, and when one had a wheel stop working, it was able to continue to drive *in reverse* for the remainder of it's time on Mars Also they realized if they parked on north-facing hills they could receive more sunlight on the panels. They were never built to run for only 90 days, but that was the planned mission since they anticipated more dust build up and malfunctions.",
"I have a follow up question. The general answer seems to be that is stopped working because dust covered the solar panels. If someone was there to clean off the solar panels, could it continue to function?"
],
"score": [
27,
13,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aqn5le | Why has it been so slow and difficult to get voice and SMS over LTE? | Even as we approach 5G deployment, many carriers who have had LTE for years don't have VoLTE, and those that do often limit it to a few specific handset models. What are the challenges that explain this slow roll out? | Technology | explainlikeimfive | {
"a_id": [
"egh5fhq"
],
"text": [
"Its primarily needs and economics based. No one is really asking for this stuff, it doesn't really change anything or meet any different needs than is already being met in the market by carriers and phones, and thus there is little reason to invest in the changes necessary to make this happen fast. If you want it done fast, its gonna cost money, but its fairly useless to start investing money into something that no one really wants or needs and isn't going to have a good return on that investment. It can wait."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
aqr8d2 | Why should you have different scissors for cloth vs paper? | I've had a lot of friends who do sewing and other fabric crafts and to the one, the golden rule for them and scissors is you never use their fabric scissors on anything other than fabric. Why is this? Why would different materials (that are both relatively soft) impact the scissors differently? | Technology | explainlikeimfive | {
"a_id": [
"egi0f11",
"egi1ogq"
],
"text": [
"I was always told that paper dulls scissors in a way that makes them hard to sharpen back to cloth cutting sharpness. The same goes for hair scissors.",
"Cutting fabric with out fraying the threads needs sharp scissors. general utility scissors get a lot more use and abuse, dulling the cutting edges or putting nicks in them. A scissor can be sharpened but most people who have special fabric scissors prefer to just keep them for that purpose"
],
"score": [
6,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
aqrqvw | With Triple A PC games being played in triple digit FPS, why is video so often shot in 24 FPS? | Technology | explainlikeimfive | {
"a_id": [
"egi4l7d"
],
"text": [
"Mostly because people tend to not like movies with super high frame rate. Movies that have high frame rate tend to have low amounts of motion blur and lose out on a lot of cinematic feel. Also movies will actually have variable frame rate depending on what the scene demands. If you have a really fast past crisp action scenes then you actually will tend to see those with higher frame rate, but normal scenes will tend to be shot with lower frame rate to avoid the \"Soap Operay\" feel."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aqsb42 | How are photos chemically developed from photographic negatives? | As done in a darkroom? What chemical process develops the film? | Technology | explainlikeimfive | {
"a_id": [
"egi996n"
],
"text": [
"When light hits the film it makes a little piece of silver from the chemicals on the film. The more light that hits an area the more little pieces of silver you get. The chemical used in the developing process, called developer, make those little pieces of silver grow into bigger pieces of silver. Another chemical is added after a certain amount of time that stops the developer from working, called the stop bath. This makes sure the silver doesn't get too big and is the right size to form the final image. Finally the silver is made permanent with the film by fixing with a fixer. The fixer is a chemical that dissolves the parts of film that weren't exposed to light. This stops the film from being light sensitive so the negatives can be used."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
aqsds5 | How did humans discover how to bake and how/has that changed with modern technology? | Technology | explainlikeimfive | {
"a_id": [
"egibdn9"
],
"text": [
"UGG have fire UGG find grain UGG eat grain UGG try smash grain before cooking UGG make porridge UGG forget porridge on fire UGG make baked grain Baked grain taste good UGG start smashing grain with water to make grain crunchies UGG not clean Ugg's grain smashing g stones start growing mold UGG not know about mold, UGG accidentally mix mould with grain and water UGG leave grain mixture in bowl When UGG cook, grain not crunchy, grain bubbly . *Scene missing, UGG refines the process ,also realises that mouldy stone makes funny grain water if it's left. UGG has bread and beer Scene missing g, people realise it's the mould on the stones (natural yeast colonies) that make the bread grow and make the grain water fun . Now UGG sell stone fuzz , ogg makes beer and igg makes bread and they trade beer bread and yeast as well as grain. Scene missing, the French go a bit mental with butter and come up with patisserie, Americans commercialise it and cram refined flour with excess yeast to make bread faster , people react badly to refined flour and yeast and suddenly everyone thinks they've got coeliacs"
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aqw66t | Why can’t the Opportunity rover restart and resume contact once it starts receiving solar power again? | Technology | explainlikeimfive | {
"a_id": [
"egixtb8"
],
"text": [
"I believe it’s down to heat. Mars is cold (given its thin atmosphere and distance from the sun). When they hibernated in the evenings or in previous dust storms, the rovers weren’t completely dormant; they still had some electronics running so they would receive wake up signals and also to keep core components warm enough to function. With a prolonged loss of solar power due to the dust storm and coverage of the panels, it’s likely it ran out of power, lost all heating and finally became unable to receive commands to wake up. (Note; I’m not a rocket scientist or a genius engineer from JPL; this comes from an interest and reading on the subject. I am not responsible for the lifespan of any rovers you send to Mars) :)"
],
"score": [
10
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aqy0qo | Why are solar panels so reflective? Doesn't that lower their efficiency? | Technology | explainlikeimfive | {
"a_id": [
"egjbnj7",
"egjgo1k"
],
"text": [
"No. One of the biggest problems with current solar panels is that the higher the temperature, the less power it generates. Even the most efficient panels operate around 20% at best. If the panel absorbs too much energy as heat, it would rapidly degrade.",
"It's on purpose. Solar panel are not 100% efficient, they simply cannot transform all of the sunlight into electricity. One of the reason is the temperature, the higher it is, the less efficient it is and the colder, the more efficient. It not really a good idea to cool them down, because you would use electricity to cool them down, which would eat at your production. But what they can do is to reflect all the sunlight that they can't transform into electricity, so the additional sunlight heat up the solar panel as little as possible."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aqytc6 | How does Autotune work and can I use it to make me sound really good? | Technology | explainlikeimfive | {
"a_id": [
"egjif81"
],
"text": [
"It changes the pitch of your voice to be in tune. You can certainly use it to make you sound great, the pop industry uses it all the time. Often artists sound a lot worse out of the studio because they are not cleaned up be the producer. The software has become much more accessible but was first around and well known from using extreme settings in songs like Cher's - Do You Believe. Edit - spelling"
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ar004n | How are kettle cooked chips made and why does this process make them healthier than traditional chips? | Technology | explainlikeimfive | {
"a_id": [
"egjs4nf"
],
"text": [
"\"Regular\" potato chips are rinsed after they are sliced. This releases a lot of the starch. Kettle cooked chips are sliced thicker and do not get that rinse, which results in harder chip after it is fried. I don't know why you say that kettle-cooked chips are healthier. At the end of the day, it's still a fried slice of potato covered in salt."
],
"score": [
12
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ar0glt | how does software work the same way with various processor architectures? | Technology | explainlikeimfive | {
"a_id": [
"egjx3xm"
],
"text": [
"AMD and Intel CPUs have the same instruction set - so this means that both types of CPUs should be able to run the exact same code. GPUs have separate instruction sets, but they have drivers, which translate what the computer is asking for into the instruction set for that particular GPU."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ar3ebm | Why is 60 FPS the "standard" that we usually expect, instead of something like 50 FPS? | \*insert something about 50 being easier to divide into seconds/milliseconds compared to 60\* | Technology | explainlikeimfive | {
"a_id": [
"egkhia6"
],
"text": [
"Frames per second were originally based on the frequency of electric power distribution, which is 60 cycles per second in the USA where most video games are made. (It's 50 in Europe.)"
],
"score": [
12
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
ar3l57 | Why do governments, schools, and big businesses (mostly) always use HP printers? | Technology | explainlikeimfive | {
"a_id": [
"egkixcr",
"egkiya8",
"egklgm2"
],
"text": [
"So they? All I ever see is RICOH",
"hp usually gives away a lot of printers for free, but makes you sign a contract to buy supplies ie ink, toner, and paper from them. so businesses jump at this due to the low upfront cost since some of those higher end printers can easily cost 10k+",
"HP has payment plans for equipment. That includes computers and printers. Like a rent to own. They also do contracts where they will replace equipment X is Y years. Maintenance contacts are also available. The willingness of HP to work with the needs of the company is hard to beat."
],
"score": [
12,
7,
5
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ar50c6 | Why aren't smart stop lights more prevalent in the US? | Technology | explainlikeimfive | {
"a_id": [
"egkxei2",
"egkwchx"
],
"text": [
"Depending on the sensors, they don’t trigger for motorcycles and bicycles which is pretty dangerous because at so e point you are forced to run a red light",
"Lights don't have to be 'smart' but it would either be abused abuse or be problematic. In michigan, the lights are very well synched. Telegraph road can be driven 50 miles without ever stopping - at least it was some 20 years ago. Vegas, in comparison, you can't even time the next light no matter what you do. Im not sure if it's due to funding, a different thinking or some other aspect. Speed limits for instance is crazy in Vegas particularly in a state that is known for drinking...and now marijuana. On top of these crazy speed limits, they have pedestrian road kill crosswalks, and they have the right of way on basically expressway speeds... Just cross the highway. Also,the buttons for crosswalks do nothing except warn the pedestrian.. In Florida, they are actually smarter. They have actual pedestrian street lights that forces cars to stop. But it can only be activated once per street/crossroad cycle as to not slow traffic. You rarely hear about Florida Man getting run over crossing the roads"
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ar6lzm | How does wireless stuff work? | Technology | explainlikeimfive | {
"a_id": [
"egl4yco"
],
"text": [
"how do you see things without touching them? Light has to bounce off the object and enter your eyes. Wireless works in the same way except the light is different, invisible only because our eyes aren't designed to see that light. It has to do with how much energy the light has. This information can be found in a physics textbook or a Wikipedia article on light. The wireless devices we use are designed to use this invisible light which has a specific energy level. It can send signals in the same way, much like turning a light bulb on or off. The way information is sent can vary from the light flickering (digital) to the light changing energy level (FM radio) to more or less light being made such as in the case of AM radio. Generally we use the term radio instead of light because of the energy level of the light used in wireless devices. It is a much lower energy than visible light, in a range of light energies we call radio."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ar6wvw | Difference between JPEG, PNG & other image formats. | Technology | explainlikeimfive | {
"a_id": [
"egl7y20",
"egle1ec",
"egl6s8o"
],
"text": [
"JPEG and PNG are very different because they have different goals. JPEG is what's called a \"lossy\" format, it uses very clever math to compress an image as small as possible while still making it appear the same. In this process it throws away some of the information of the image but if you keep the settings high you'll never notice (also recompressing _with different base parameters_ will make the image progressively worse quality for each time it's saved, this is why re-shared JPEGs become blurry and blocky). Because of the way this compressin works, JPEG is not capable of storing transparency (If I recall correctly, JPEG2000--a variant of JPEG is capable of storing transparency--but that format is rarely used). PNG on the other hand is a \"lossless\" format, it will not throw away any of the information in the image, what you put in, you get right back out again. The compression in the format is kind of like a zip file, but specifically designed for images. It also supports four _channels_--red, green, blue and transparency. To also answer /u/Gwiel's question, this means that JPEG is really good for storing photos, they're usually fairly high resolution images that it doesn't matter much if a few pixels are bit off in and JPEG will make them small and easy to transfer. PNG on the other hand is often used for icons, replacing the venerable GIF format on the web (unless you want animation which PNG officially does not support).",
"You have 30 beans: - 11 Green - 9 Red - 10 Blue You want to send the information of how many beans you have through the bean postal service to your cousin in New Beanland, you have a choice of two containers: JPEG: it costs roughly $5, but can store only 3 beans. However, when the information is displayed to your cousin, everything will be multiplied by 10. So you put in 1 Red, 1 Green, and 1 Blue bean. Your cousin will therefore be told you have 10 Green, 10 Red, and 10 Blue beans. That’s VERY accurate, but not exact. If you’re ok with that then you can save some money. PNG: Costs $1 per bean. But because you’re broke, you put all your beans in the box. When your cousin receives it, he’ll know exactly how many beans you had. However it cost you $23 to send the information. Basically: - JPEG is smaller but isn’t an exact (but very close) representation of your image. - PNG is an exact representation of your image, but larger as a result.",
"Folllwup: is there a specific reason for one over the other? In which situation would I rather want to use PNG, in which JPEG?"
],
"score": [
31,
7,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ar8m1q | Why do PC programs that emulate game consoles run so slowly, even if the pc's hardware is more advanced than that of the console it's emulating | Technology | explainlikeimfive | {
"a_id": [
"eglgal0",
"eglgakx"
],
"text": [
"Because emulation is basically your system pretending to be another system. Imagine trying to imitate an old man. Even though you are probably much more physically capable than him, you’d have a hard time behaving exactly like him.",
"Because emulation in real time is really hard and complex. Think of it as the computer translating on the fly from one language to another, but the languages don’t line up perfectly so adjustments need to be made, all slowing it down. It’s the same concept as why live subtitles that are written over TV programs for the deaf often have errors and don’t match well the speech coming through the audio."
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ara9ox | How does asymmetric encryption work? | Taking A-Level Computer Science, and I'm very comfortable with the majority of concepts that I study. I've never really understood asymmetric encryption though - outside of my studies, having read about public/private key encryption and SSL, understanding how the communication works at a basic level, the only thing that really throws me is how you can encrypt something and not be able to reverse it. Are there any explanations or examples? Thanks! | Technology | explainlikeimfive | {
"a_id": [
"eglu07n"
],
"text": [
"The trick is to find problems that are easy to calculate in one direction, but difficult to reverse. Then you base your algorithm on that kind of problem. For example, plain multiplication does NOT have that property. Division is pretty much just as easy to perform as multiplication, so those two things are not suitable for asymmetric encryption. If I tell you that I multiplied 12 by some number and got 120, it's trivially easy for you to reverse that and figure out that the number I used was 10. But there are some problems that are not easy to reverse like that. Factoring large prime number products is one of them. If I tell you that I multiplied two large primes and got 56713727820156410577229101238628035244, it wouldn't be simple for you to figure out what those prime factors were. With a computer you could eventually do it, of course. But if I make my primes REALLY damn big so that the resulting product is REALLY REALLY damn big, your computer program will probably take a long, long time to factor it. Like centuries, or millennia. And that's good enough to use it for encryption. Factoring the products of large primes is not the only problem that is hard to reverse like that, but it's the one that is probably used the most and is easy to understand."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
arbuyi | The Google File System (2003) | Technology | explainlikeimfive | {
"a_id": [
"egm7jqm"
],
"text": [
"You need to understand why Google implemented the Google File System, and this was not their first attempt at such a system. Google made its fortune in the search business. And their approach required a huge database. Much larger then could be stored on a single server. But they could not afford huge datacenters of servers either. They had to use cheaper desktop computers, and often old discarded computers at that. So instead of one big database server they had to use lots of old cheap desktop computers that frequently broke down. So they had to implement a way to store and retrieve data on all these computers even when it was expected that computers would crash or corrupt data. If you understand these issues the paper actually does a good job at breaking down the details of the implementation."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
arfak3 | Why is the time shown on the clock different between Android, iPhone and Windows? | The time on my Android phone can be 10:00, but my iPhone will show 9:58 and my Windows PC will show 9:57. Why is that? Don't all these devices get the time from a server? Are they all different servers? If so, why the slight differences? Which one's the most accurate? I'd always imagined it's the iPhone since Apple said the Watch is accurate at something like -0.15 seconds or something, and I don't see why the iPhone can't use the same server the watch does for the time, they're both running the same code. I'm very confused about all this. | Technology | explainlikeimfive | {
"a_id": [
"egms8nk",
"egmtow0"
],
"text": [
"Depends how often the device resyncs and at which rate the device loses / gains time. It in the United States, you could manually check on URL_0 , or tune into Shortwave radio time broadcasts.",
"Most devices get their time from the same place : URL_0 . the idea behind this is that if all the time servers (ntp servers) are part of this server pool, then time requests can be balanced equally around servers, and the servers can all be synchronised. Any internet capable device can request the time from ntp servers. In the past, companies would add in time synch as a rushed feature, and then ship the device to customers. A famous example is a model of router that would request the time every 5 minutes from URL_0 , flooding the servers with requests. To avoid this, they recommend to device manufacturers minimum time limits between server calls. This means in practise a device may only check the time online every few hours, maybe up to a day. This allows for a small amount of error to build up every day. Let's assume that your android phone time drifts at a rate of 2 seconds per hour backwards, and your iPhone drifts at a rate of 2 seconds per hour forward. At this rate, every hour, the clocks separate by 4 seconds. At this rate, it will take 16 hours for a drift of 1 minute and 4 seconds to build up, enough to allow the clocks to display a time 2 minutes apart (just). This is compounded by the fact that certain devices don't go online much. I know people with iPhones who switch off the mobile data unless they're specifically trying to go online because it drains the battery so fast. In this instance, it's pretty reasonable for them to leave mobile data off for hours on end, allowing their device clock to desynchronise"
],
"score": [
7,
6
],
"text_urls": [
[
"time.gov"
],
[
"pool.ntp.org"
]
]
} | [
"url"
] | [
"url"
] |
arfkjr | Why do cameras have a hard time capturing electronic screens? | Technology | explainlikeimfive | {
"a_id": [
"egmw1dp"
],
"text": [
"Still cameras have a problem with the moire effect. That's where the rows and columns of the display sometimes coincide with the rows and columns of the camera sensor, and sometimes they don't coincide. That causes weird lines in the image. Video cameras also suffer from flicker if the display has flicker which is at a different frequency than the camera's frame rate."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
argca0 | How did game genie work? | Technology | explainlikeimfive | {
"a_id": [
"egn0wrl"
],
"text": [
"Game Genie and Gameshark both worked by editing specific hexadecimal that transfers between the game and the system's RAM. Part of the input code is the location of the address that it will to edit, the other is the edited string that it will insert once the address has been found and intercepted. Actually quite simple, still very doable on PC with Cheat Engine."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
argy6m | Why do games render cutscenes real time instead of the cutscene just being a video that plays? | Technology | explainlikeimfive | {
"a_id": [
"egn543t",
"egn7hog",
"egn53sa"
],
"text": [
"More flexible and cheaper. In-game cutscenes mean you don't need external models and art, in addition to tooling; you can use your engine for everything. It's also easier to change something. If you want to change what happens, then you just do it; you don't have to re-render it. Also ages better, though I'm not sure anyone cares in the moment.",
"Pre rendered cut scenes are difficult to make. Cut scenes made in engine are easier to create and easier for the game to handle. Pre rendered cut scenes require a team of animators to made the cut scene from scratch, while in engine cut scenes simply require the game to write scripts for the in game assets that were already created, you can't just take the model for a character and copy and paste it in a pre rendered cut scene. Pre rendered cut scenes also take up a lot of storage space for the game. Pre rendered cut scenes also need to be loaded, while in engine cut scenes already have all the assets loaded from gameplay, so it's a seamless transition. It saves time, money, resources, processing power, storage space, and load time.",
"I would assume file sizes since most games with cut scenes are already large games also custom characters, different entrances, different scenes for what progress you already have done"
],
"score": [
11,
4,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
arhpy0 | When using a phone on speaker, how does the phone cancel out the incoming noise of the persons voice on the other side? | Curious | Technology | explainlikeimfive | {
"a_id": [
"egnb21l"
],
"text": [
"When on speaker phone mode, the phone compares the audio it picks up with it's mic to the audio it knows it's sending out of the speaker. Anything that's the same gets cancelled out. The algorithms are more sophisticated than that but that's the basic idea. & #x200B; When in regular handset mode, the mic is too far away from the ear piece to pick up the sound of the caller."
],
"score": [
15
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
arlfas | if someone did a Hollywood heist on your bank and took all its money would your bank card still be able to buy things? | Technology | explainlikeimfive | {
"a_id": [
"egnya6g",
"egny8gd",
"egny91s"
],
"text": [
"Yes. For several reasons. One reason being, that a bank franchise has many buildings - and just one building has been emptied out. Far more importantly though, a bank robber can only steal the bank's physical money. But these days banks typically do not have a lot of actually money at hand. The overwhelming majority of money exists only in digital form and is only being transferred from computer to computer. Your bank card is a way to transfer money digitally. And that digital money cannot be physically stolen.",
"Banks dont usually keep all their money in a vault, and they have insurance, so yes you would be fine",
"Your bank balance is simply a number in a computer database somewhere. There's absolutely no connection between it and a stack of bills sitting in a vault somewhere. There's banks these days that *don't even have physical branches to store money in*. & #x200B; Your bank account, at least in the US, is also insured so, even if the bank lost *all the money*, the government would make sure you got your money back."
],
"score": [
5,
3,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
arm575 | the difference between IMAX 3D, Dolby Digital 3D, and Real 3D? | Technology | explainlikeimfive | {
"a_id": [
"ego53f5",
"egoic1c"
],
"text": [
"Imax is big, real big, need special cameras big Dolby digital uses circular polarized lenses and can be on a bigger screen than Real D. If you are in the side seats you are less likely to get blur. It also uses a silver backing screen like the old movies which actually results in deeper blacks and whiter whites because shiny. Real D uses a white screen and their lenses are polarized differently. Because of it this method only works on a 30ft screen unless they have multiple projectors, people on the ends of rows tend to see blurring, and the color range isn't as high.",
"Source: I've worked at more than 1 of these companies and have worked closely with people from all 3. & #x200B; Imax 3d comes it two flavors: xenon and laser. Both flavors also undergo the DMR process which is an image enhancement process which reduces noise in the image. While IMAX is known for their large screens, that is not necessarily a part of their 3D offering, that is to say, IMAX 3D can be shown on a smaller screen. & #x200B; IMAX Laser 3D uses 6-primary 3D technology. This means that they use different wavelengths of red, green, and blue for each eye. So they have 6 different laser light sources being piped into 1 or two projectors. They project both left and right images simultaneously on a matte white screen. The glasses then filter out the appropriate wavelengths for the left and right images. & #x200B; IMAX Xenon uses two standard projectors, each projecting either right or left eye simultaneously on a silver screen. In this case, the images are polarized using linear polarization. This means if you tilt your head sideways the 3D effect is lost. The screen has to be silver because the metal retains the polarization of the light that hits it. A matte white screen will absorb the light's polarization. Some people don't like silver screens because they reflect light more directly, meaning that they are brighter directly in front of a viewer than they are in the corners. This is called a hot spot. & #x200B; Dolby Digital 3D also uses the 6 primary technology used by IMAX laser. They use 1 or 2 projectors, but usually 2. They use xenon or laser although they have been trying to upgrade most of their systems to laser. Dolby Digital also tends to include ATMOS sound which uses arrays of speakers to generate a 3 dimensional sound experience in which they can place sound \"objects\" anywhere in the theater. & #x200B; RealD uses 1 projector, and projects the left and right images sequentially, usually flashing both left and right images 3 types per frame. There is a liquid crystal polarization screen that sits in front of the projector lens, this flips its polarization state in sync with the projector's left right flashing. RealD uses circular polarization on a silver screen. The circular polarization means that a viewer can tilt their head without losing the 3D effect. This also makes RealD's 3D technology projector agnostic, meaning they don't need a special projector set up to operate. This among many other reasons is why RealD holds the lion's share of the 3D marketplace. RealD also has its own special silver screen which addresses the issues with \"hot spots\" and is more efficient in its reflective properties making it brighter than a normal silver screen. & #x200B; & #x200B; & #x200B;"
],
"score": [
18,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
armek0 | How do flight suits or g suits work and what do they do for military jet pilots? | Technology | explainlikeimfive | {
"a_id": [
"ego54au"
],
"text": [
"One of the effects of high Gs is that your blood pools in your legs - it's pushed to the outside of the curve along with the rest of your body. This causes blackouts as your brain is deprived of oxygen. G suits have inflatable sections in the thighs that squeeze the legs tight and prevent the blood from pooling there, keeping it in the upper body (ideally the brain)."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
armpt8 | How do we get weather data and how come it's so unreliable sometimes? | Technology | explainlikeimfive | {
"a_id": [
"ego7ocg"
],
"text": [
"It’s a very very complicated system. There is a network of weather reporting systems. Meteorologists take the information reported from those systems and plug those into simulations. Unfortunately weather is extremely sensitive to tiny differences in measurements. Imaging a simulation running on the real data and a simulation with a hundredth of a degree difference in temperature from one weather station: their predictions would look very different after a while, even though they were almost entirely the same at the beginning. Since no weather reporting system can be precise to the point that we would be able to perfectly report the weather, it still varies quite a lot from our forecasts. A whole lot of unpredictable things that the reporting systems can’t catch end up being very influential."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
armvt5 | How is nuclear energy cleaner than other methods of renewable energy like wind energy and solar energy? | Technology | explainlikeimfive | {
"a_id": [
"ego8pcm",
"egoagib",
"ego95ut",
"egoo42s"
],
"text": [
"I believe it all comes down to the sheer amount of energy that is produced vs materials and upkeep needed. For instance a wind turbine costs thousands of dollars worth of materials and only has a lifespan of about 25 years or so. But nuclear energy lasts much longer and delivers much more power for a lower price per watt.",
"Nuclear energy isn't renewable is the first point however it uses uranium which isn't a fossil fuel so it doesn't produce carbon dioxide. You hear it described as cleaner but is produces a huge amount of energy all day every day for not a lot of fuel. Both wind and solar require expensive batteries to store the energy when it isn't sunny/windy which have a large environmental impact. In addition, wind and solar produce a comparatively small amount of energy for a lot of investment. The waste produced by nuclear fuel is stored in drums and put in old mines. This is a problem but it isn't spewed into the atmosphere like coal and gas stations so it is clean and produces the same amount of energy. There are prototype reactors which use Thorium isotopes which don't have the same waste issues as uranium reactors but these aren't commercially viable at time of writing (fingers crossed!) This is fission reactors. Basically its a stop gap before the renewables are fully fledged. Kurgzesacht did an excellent series of videos on nuclear energy which I suggest you Google. The silver bullet is fusion reactors which produce and insane amount of energy only using hydrogen as fuel and producing helium as waste (in theory). This is the process the Sun uses to produce energy. The problem is that we don't know if this is viable on a large scale on Earth without gravity as strong as the Sun's, let alone commercially! Again, this process is awesome and some of the most interesting physics you can find without an obscene prior knowledge.",
"This isnt an answer to your question but radioactive materials used in nuclear energy are not renewable. Renewable refers to sources of energy that can be replenished within a reasonable time frame such as Wood which can be grown relatively 'quickly' opposed to radioactive elements which were formed millions of years ago.",
"Good question- it's not the 'cleanest' and as others have said it's not really renewable but there are a lot of differences between nuclear and wind/ solar: \\- nuclear is good for providing a baseload of energy, ie the energy it provides needs to be at a constant level, you can't turn nuclear plant on and off depending on demand fluctuations. That's why, looking at things from a system level, eg a whole country, it fits well with gas, because gas plant is more flexible and can cover the peaks in demand, eg in the evening when everyone gets home from work. On the other hand wind and solar are intermittent, ie they only work under certain conditions and the demand levels they provide are not stable, so they are not good for covering baseload demand. A higher penetration of intermittent renewables would also need improved and increased storage technologies. \\- nuclear means large centralised plant which fits the transmission and distribution networks that most developed countries have at the moment. On the other hand higher levels of wind and solar would most likely require network upgrades (due to intermittency), as well as changes in the way we as consumers use energy and the way our appliances operate. Specifically regarding solar it also depends on whether we are talking about large scale solar farms or rooftop PVs for people's homes. \\- with nuclear waste management and decommissioning is an important issue (problem?), much less so with wind/ solar. \\- the implications for energy security are also different- some people claim that nuclear increases energy security for a country because uranium is generally considered a safe resource in terms of geopolitics. the same people tend to claim that wind/ solar would make a country 'less safe' because a higher level of interconnections with other countries may be required. However there is also the view that higher interconnection between countries is actually safer because it promotes cooperation and that generally a more diverse national energy mix is the safest option. Also sometimes nuclear operators and developers are state-owned by a different country (eg EDF in France) so the sovereignty argument in favour of nuclear is slightly more complicated than sometimes presented. \\- in terms of economics both nuclear and wind require large upfront investment. offshore wind cost are rapidly dropping and generally wind farms are easier and cheaper to operate once they're up and running. I hope this helps, let me know if anything doesn't make sense. It's important to keep in mind that each option generally implies a significantly different energy system in the future and therefore a different level of fossil fuels (because generally you'll need some fossil fuels as back up), a different role for consumers, different energy networks, different skills, supply chains etc. It's also worth noting that energy is very politicised so when you hear about energy issues in the news etc you should always consider the source. It's all very interesting!"
],
"score": [
8,
8,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
arolsa | What does the curing light at a dentist’s office do? | Technology | explainlikeimfive | {
"a_id": [
"egokpfj",
"egolank"
],
"text": [
"Basically, the resin that the dentists apply to your teeth is made up of short-chain compounds, which is why they can flow easily. Shining the light on the compound induces chemical changes that make the compounds get a lot longer and tangle up with itself, causing it to harden and attach to the surrounding tooth.",
"Polymers are the materials called 'plastics' by the general public. They are molecules which look like long chains, usually with a backbone of carbon. The resin is thus like a bowl of wet spaghetti but shorter than most other polymers, so it's like the tinned spaghetti. Ultraviolet light is shorter wavelength than visible light and so has more energy per photon. The UV light has the right energy to make these long chain molecules form cross-links (molecular bonds) with adjacent spaghetti. When each spaghetti is linked all over the place to other spaghetti pieces, the whole thing solidifies and becomes rigid. This is not unlike the process of vulcanisation of rubber for shoe soles and car tyres. Instead of UV, they add sulphur to the liquid rubber that promotes cross-linking and makes the rubber less ductile."
],
"score": [
11,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
arprxh | How does NASA figure out where to send rovers when sending them to outer space? | Technology | explainlikeimfive | {
"a_id": [
"egoxh1i"
],
"text": [
"The rovers that landed on Mars were launched after nearly 50 years of study from orbit and other probes. Plus centuries of observation from Earth. URL_0 Find an area on the planet that has stuff you want research using the sensors on the probe, has the terrain the rover can navigate. There are studies with the scientists, rover designers operators and management that will find a suitable site for exploration"
],
"score": [
7
],
"text_urls": [
[
"https://en.m.wikipedia.org/wiki/Exploration_of_Mars"
]
]
} | [
"url"
] | [
"url"
] |
|
arshi7 | How does Alexa work so quickly and accurately when it supposedly isn't listening-in at all times? | Technology | explainlikeimfive | {
"a_id": [
"egpeob7",
"egpfdmw"
],
"text": [
"Funny you should ask this. My kid turned off Alexa’s mic(so now she can’t hear us) I asked her too do 3 things in a row with no response... she said, just so you know my mic is off. She is always listening",
"It is always listening, I think I read somewhere it analyzes the last 4-5 words said for \"Alexa\" to start doing something."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
arva1b | Why do plugged in electronics drain power when not on? | Ignoring advanced technology like TVs and anything with a standby feature. Why does having something plugged in waste energy even if it's not on and not completing a circuit? Simple examples like a toaster, phone charge cable, or extension cord. If they're not on/active, aren't they still an open circuit and basically just an extension of the outlet? | Technology | explainlikeimfive | {
"a_id": [
"egpykvm",
"egpxb4x"
],
"text": [
"Extension cord does not use power when nothing is plugged into it. A phone charger has components inside it that can draw power even when a phone is not connected such as capacitors. A toaster will not use any power when not in use unless it has a clock or an LED on it.",
"Sometimes they are. The item has a mechanical switch, and is truly off when it is not being used. An extension cord really does not use power. It is just a wire. So it is with most toasters and jugs - there is a mechanical switch that actually turns it off. A phone charger is an active device - as long as it is on, it generates 5 volts on the output, which takes a little power. But as a clue - such a device is turning all the electricity it is drawing into heat, so if the device remains cool to the touch, any amount of power it is drawing is negligible. Older power supplies use large, bulk transformers. These always draw considerable current to create magnetic fields in the transformer, and so are usually warm. These old, large 'wall warts' should be unplugged to save power."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
arxvrq | What's the working difference between 4G and 5G that will allow up to 100 times faster connections? | Technology | explainlikeimfive | {
"a_id": [
"egqdcv0"
],
"text": [
"In addition to all the frequencies that 4G is using, 5G can use very high frequecies as well. These high frequencies can carry more data, but they are also absorbed by air much more easily. They have a hard time penetrating walls, and the highest frequencies can't even get through rain. So over long distances, 5G isn't actually going to be much faster (if at all) than 4G, since it uses more or less the same technology. The new high frequencies will be used mostly in densely populated areas, where the short range is not an issue. This will be particularly useful in crowded areas, such as airports and train stations. Think of it more like a long range W-LAN than traditional mobile internet."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
as0exq | How are digital maps (google maps, Apple maps) able to assess and display live traffic conditions? | Technology | explainlikeimfive | {
"a_id": [
"egqujyb"
],
"text": [
"They use location data from people's phones. If a bunch of iphones are moving slowly down the highway, Apple knows there is traffic there."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
as0lys | How exactly does "remastering" a game work? | Is it more like slapping a new coat on an old car or do you have to essentially build the whole thing from the bottom up again? | Technology | explainlikeimfive | {
"a_id": [
"egqwh54",
"egqws2c"
],
"text": [
"There's not really a clean cut and were to this. The general consensus is that a remaster is , yes, just slapped on HD textures. There are also \"remakes\" which are thought of as a complete redoing of a game that isn't always 100% the same as the original. There are also games like Crash and Spyro that were made from the ground up but (as far as I know) are exactly the same as the original.",
"It really depends on what the game developers want to do. The core concept of a “remaster” is having a more modern version of an old game. The game play, the environment and all the little quirks that make that old game unique. Some remasters are just improving the graphics. Some are adding content or fixing notable bugs. Most of the time, game devs put their games on a new or upgraded engine (these upgraded game engines allow for those upgrades to the game). And to answer your question about being built from the ground up, it really is not. The core concepts and the logical systems are already built. They just have to put it in a different form."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
as10r5 | how does Bluetooth work? | Technology | explainlikeimfive | {
"a_id": [
"egqzsjr"
],
"text": [
"Bluetooth is a type of radio. The radio has very low power, so it only goes a small distance. There is a protocol for use over the radio, like the internet protocol used over wifi. This protocol covers things phones do, like make calls and relay sounds. The same protocol supports headphones, with or without a microphone. There is also a data message, for things like transmitting the phone's contact list or the name of the song that's playing."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
as3cyc | How does the Nintendo Switch record the last 30 seconds of gameplay after you hold down the screenshot button? | I've seen that Microsoft has the same kind of thing with their game bar built into Windows 10. Do those programs record at all times and delete anything before 30 seconds ago? Wouldn't that use a lot of resources? | Technology | explainlikeimfive | {
"a_id": [
"egrgoy5",
"egrhgau"
],
"text": [
"From what I understand, it’s always recording your screen. At what time it chooses to delete the footage, I don’t know. I’m guessing that after the max time you can choose to record (I think for Microsoft it’s like 5 minutes) it will over-right the old footage with what’s happening now. I does take up space, but not a lot.",
"The data that gets sent to the screen also gets stored in a queue in memory. It uses enough memory to save up to 30 seconds worth of video. It overwrites older data as new data is generated"
],
"score": [
8,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
as3xwg | Why can't a phone connect to multiple speakers via bluetooth? | Technology | explainlikeimfive | {
"a_id": [
"egrlb4p",
"egrlhm6"
],
"text": [
"It has to do with the frequency range of Bluetooth, and the fact that your devices don't have two transmitters.",
"It can--there are some new technologies out now that allow it, but only with certain hardware, and the new Bluetooth 5 spec appears to allow streaming to at least two devices at once. We're getting there!"
],
"score": [
5,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
as4opj | 4K and 8k. How many K’s could we go to? Is there a point we couldn’t distinguish between K’s? | Technology | explainlikeimfive | {
"a_id": [
"egrvkaw"
],
"text": [
"1K = full HD = 1080 (1,000 = 1k). So a full HD phone screen, small as it is, has a gorgeous image but you almost can't see the individual pixels of color. By comparison, a 70 inch TV that's merely 1k, you can definitely see the pixels, and a huge stadium screen, the pixels may even be as big as flashlight bulbs / LEDs. So as long as we can make bigger screens, it helps to have more K's. But it's not just a matter of the quality of the screen itself, or how small / how many pixels of color we can cram into it. Because every pixel has to be \"lit up\" individually, and 60 frames per second, means there's a lot of bandwidth required to display a smoothly-moving image. In fact, because the screen is an area, the amount of bandwidth required increased with the square power of the K's. 8K requires 64x more bandwidth than full HD, and at some point we reach a limit for how much can be transmitted, even via cable, and also how much can be stored, even with today's large hard disks / memory systems. A full HD movie, compressed, requires [48 GB]( URL_0 ). An 8K version of the same movie, with the same compression, would require 3 TB, or 60 blu-ray disks."
],
"score": [
7
],
"text_urls": [
[
"https://www.quora.com/How-many-GBs-are-used-for-streaming-a-2-hour-HD-movie"
]
]
} | [
"url"
] | [
"url"
] |
|
as5ojl | How do fire engines change traffic lights when they hit red? | Technology | explainlikeimfive | {
"a_id": [
"egryrxm",
"egrz9yk"
],
"text": [
"If you look at some traffic lights, you can see a little sensor by the lights, the fire truck has a strobe light that triggers that sensor and causes the light to switch.",
"Yes. Some of the modern ‘strobes’ are IR LEDs and flash a unique code that is recorded so it can be identified if cloned and used nefariously."
],
"score": [
11,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
as7gns | how does internet work really ? where do all those fiber optic cables connect ? | Technology | explainlikeimfive | {
"a_id": [
"egseq7q"
],
"text": [
"This is a large question and I will leave out the technical details and make it ELI5. If you want to know every detail start here and work your way through the buzzwords: URL_0 Where do they connect? Here is a nice map of all the submarine fibre optic cables: URL_2 For landlines there is no public map I know of. How does the internet work? There is no one who controls the internet alone. Technically it is a bunch of different companies laying different cables around to build there own network. Some companies do this more local, i.e. in a city, others more global in the whole countries and only a few world wide. These companies create what is called a wide area network (WAN). Then connect there own WAN with neighboring WANs to exchange data between the two WANs. This is called peering. This way a customer connected to WAN A is now able to reach customers of WAN B. You might say there a two different kinds of companies out there, providers and carriers. Providers are the ones that provide you with a landline to there own WAN. Carriers are companies that build specialized WANs to connect different providers with each other. But sometimes this distinction is not that clear. All this creates a (densely) meshed network around the planet, where every one is connected to every other one else either directly or through a connection with someone else. Thus customers from everyone can reach each other. Voila: The internet. Edit: Whom do you pay? You are (in most cases) paying your local provider. This the one who took the effort to provide a landline to your house. Normally called an ISP (internet service provider). From your question I get the impression that you do not have a landline. In this case you are paying the one who took the effort to set up landlines to geographically good locations (big buildings around you, hills, that sort of thing). And at these points built access points for a wireless network. This could be WLAN or a cellular network or some other wireless technoligy. Companies specialized in wireless/WLAN provisioning are sometimes called WISP ( wireless ISP). IMHO there is no real difference except for the technoligy in use. Edit 2: At the end of the day, the internet is based on a huge fiber optic backbone. Light is the only transport medium with which provides enough distance and speed for the amount of data we shuffle around the globe. Check out the german internet exchange DE-CIX. It is the largest traffic junction on this planet. It's located in frankfurt and is a peering point (internet exchange or IX) for most european providers/carriers anda lot of the traffic between europe and us. Here is there traffic statistics, and it is in terabits per second: URL_1"
],
"score": [
6
],
"text_urls": [
[
"https://en.m.wikipedia.org/wiki/Internet",
"https://www.de-cix.net/de/locations/germany/frankfurt/statistics",
"https://www.submarinecablemap.com"
]
]
} | [
"url"
] | [
"url"
] |
|
asaeau | Why does it matter how you charge a battery with respect to long-term life? | Never fully charge? Deep discharge? Type of battery matter (phone vs car)? What really is best and why? | Technology | explainlikeimfive | {
"a_id": [
"egsteji"
],
"text": [
"It depends on the battery type. Phones laptops and newer electronics have lithium ion batteries. Older stuff has Nickel Cadmium. The older style batteries had what is called the memory effect, so if you recharged them when they were half empty, this became the new zero after a while and your battery would only last half as long. Therefore the recommendation as to deep discharge as much as possible before recharging. Lithium Ion batteries don't tend to do this as much and can be recharged at any level provided you stay above about 20% and below about 80% Neither battery likes to be left permanently charging at 100% so try and avoid overcharging where possible. A car battery is an entirely different thing and provided you don't run your lights all night should live a normal life recharging itself as you drive. > What really is best and why Discharge whatever it is as much as possible and don't charge it to 100% the battery will last longer due to the electrochemistry of the cells. Charge it when you need to and try not to leave it stored with a lot of charge."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
ascj7p | How are there Damascus steel knives if we don’t know how to make it? | [take this post for example]( URL_0 ) how are they using a brand new Damascus steel knife, I thought we didn’t know how to make it? Or is it not “true” (if that’s the right word) Damascus steel and just an imitation? | Technology | explainlikeimfive | {
"a_id": [
"egt9d6c",
"egtabl5",
"egtkr04",
"egt9952",
"egtlawd",
"egtmsn3"
],
"text": [
"We do know how to make it and actually can make better with modern processes. This is one of those yarns about ancient technology being mysterious and better. Total BS.",
"We know how to make Damascus steel. The problem is that the process we use to make it utilizes materials and fluxes which hadn't been invented when the original blades were made. So, they had a different process, using different raw materials. What's different is particularly interesting because the process that they could have used in antiquity would have to use something we don't have any evidence they knew about.",
"What we call damascus steel today is a the name of a certain look, made by forge-welding layers of steel together. There is an automatic visual layering effect happening because the contact surfaces where the layers are welded together have different carbon content to the rest of the steel, even if all the layers are the exact same alloy. Usually though, the pattern is enhanced by intentionally layering steels with different properties and then etching the finished product with an acid, which darkens the steels differently, creating a stronger contrast. The psttern created by the weld surfaces created by forging the steel into one piece is also what people mean when you hear terms like \"wire damascus\" which is created by forging steel cable into a solid bar, or \"chain damascus\" which is forged from a piece of chain. On top of this, there are different names for different and some times really complex patterns created by twisting or cutting and reforging the layered steel. Ladder damascus, wave damascus etc. The bottom line though, is that all of these methods are called \"damascus\" because of the resemblance to the surviving damascus steel artifacts with their characteristic patterns caused by different structures in the steel. The methods and materials of historical damascus sword have very little in common with modern day mass produced knives with \"damascus\" steel.",
"They are just imitating the pattern from my understanding. Using various metals or different grades of steel for the color change...",
"The types of ores, smelting and forging techniques that the original craftsmen used to make damascus steel is lost. We have reverse engineered the products and can make similar products using modern steels. Part of the problem is modern steels are of a different alloy type, so the raw materials are no longer commercially available.",
"Metallurgist by training but work outside the field so I'm working from memory. Damascus steel is commonly used today to describe a layered structure of forge welded steels. This is something we have known to make for a very long time. It's benifit is improved toughness while retaining edge retention. It is also pretty for certain values of pretty. The other type of damascus is an ancient type of damascus made from ore that came from India. It is characterized by the formation of spherical carbides during heat treating. For the day it had excellent ege retention and toughness, both extremely important in a fighting blade. I recall reading a paper on mass spectrometry tests on a number of these blades and they had very specific alloying elements and carbon contents and would likely have come from a limited number of mines. The sword makers of damascus that knew the heat treat to make this steel would have kept it as a trade secret. Additionally the process would only work with the appropriate alloying elements. Add those two together and it becomes easy to see how the process might get lost. The material i was reading was almost 20 years ago. At the time a knife maker in Finland was selling a traditional knife called a puukko claiming it was made with the second type of damascus. I couldn't find it today."
],
"score": [
20,
16,
7,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
ascpfd | What is the relationship between resolution, frame height and width, data rate and file size? | What I know so far, from watching Youtube videos, is that there are several common resolutions like 720p and 1080p. Those will be 1280x720 and 1920x1080 pixels. But then why are some videos of the same resolution (and approximately same duration) so different in file size? I am guessing it has got to do with the data rate, but how does it actually work? If I have a 1920x1080 video with an initial data rate of 8160 kbps and send it through a file converter such that it has a new lower data rate, does it affect the video quality in any way? Can it still be considered 1080p? | Technology | explainlikeimfive | {
"a_id": [
"egtcp2d",
"egtbbyb"
],
"text": [
"> What is the relationship between resolution, frame height and width... Aspect Ratio is the numerical way of expressing the difference between the width and height of an image. For instance, an image with a resolution of 1920x1080 has an Aspect Ratio of 1.78:1, meaning it is 1.78 times wider than tall; this is also sometimes expressed as \"16:9\". Every resolution is tied to a specific Aspect Ratio, i.e. 1080p will *always* have an aspect of 1.78:1. However, this rule doesn't remain true \"in reverse\", which is to say that a given Aspect Ratio isn't tied to any one specific resolution. For instance, an image captured at 3840x2160 has double the amount of both horizontal and vertical resolution that 1080p offers, but the aspect ratio remains at 1.78:1, and likewise, 720p also yields a 1.78:1 asepct, it's simply a matter of maintaining the ratio as resolution goes up or down. For the sake of comparison, old \"square TVs\" (they aren't actually perfectly square) have an AR of 1.33:1, and the \"defacto standard\" for motion pictures was 1.85:1 for many decades, although other filming standards exist as well. > But then why are some videos of the same resolution (and approximately same duration) so different in file size? Different codecs reduce video size to different degrees and using different methods, so depending on how the video was encoded, you can maintain common resolution while file sizes change. > I am guessing it has got to do with the data rate, but how does it actually work? Data rate (bitrate) can be a *part* of it, but it's not the entire story; it is possible for a given codec to use more aggressive or less aggressive compression than another comparable codec without the bitrate changing. So, it's possible for 2 videos to both be encoded at 1080p at the same bitrate, but with one using more aggressive/less efficient compression that will visibly degrade video quality and/or cause issues like mpeg blocking, etc... Essentially, compression scheme, resolution, and bitrate all effect how video quality works independently of one another. There were some interesting DVD releases marketed under the name \"Superbit\" that omitted bonus material in lieu of using the additional disc space to encode at a higher bitrate. The resolution and encoding scheme didn't change, but they were able to realize improved A/V quality through the use of a higher than normal bitrate. > If I have a 1920x1080 video with an initial data rate of 8160 kbps and send it through a file converter such that it has a new lower data rate, does it affect the video quality in any way? Yes, as bitrate drops, so does video quality, but whether the difference is noticeable depends on specifics not addressed here. > Can it still be considered 1080p? Yes, if a video file has a resolution of 1920x1080 and is \"progressive\" (non-interlaced), it is a 1080p image regardless of anything else.",
"Compression. Video data is ginormous: a single frame of 1080p video is ~6MB. That's 144MB per second. To make streaming (or anything really) possible video has to be compressed, at lot. There exists many different video compression algorithms, but they all allow you to set a target bitrate. The algorithm will try to pack the most quality possible in this bitrate.. Of course, the lower the bitrate is, the lower quality the video will be. Some algorithm are better than others at preserving quality, but they all degrade the video to some extend. > Can it still be considered 1080p? Yes, depending on the compression and bitrate it might look like shit though. That's why video sharing sites often display the algorithm and bitrate with which the video was compressed (the most popular algo is probably h264)"
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
asd59q | How was it decided that wireless mouse drivers need to weigh in at hundreds of megabytes? | Technology | explainlikeimfive | {
"a_id": [
"egtivaz",
"egtgj95",
"egtfkfc"
],
"text": [
"It's probably mostly two things: 1. Dependencies. A full .NET framework, or whatever they used to make it. Which may not be necessary on your particular system, but they'll still include it because some people will need it, and telling users \"go to URL_0 and download this\" doesn't look very professional, and is going to confuse some people. 2. High res graphics. Because a plain UI is too boring in this day and age, and a low res image would look wrong on a 4K screen, so it's likely that whatever images and animations are included are in high res to make sure it looks as shiny as possible, and doesn't make people regret spending $80 on a mouse.",
"I strongly suspect the drivers you've downloaded or installed aren't written for JUST that specific mouse. Very often, drivers are written for every device in a generation of hardware (about 2-3 years, depending on the function (video card, mouse/keyboard, printer, etc.)). Also, since it's logitech, it likely also includes software for remapping buttons based on application, something that would have been tricky if not impossible in the Win2k days.",
"The problem with drivers is hardware variability. The driver file contains all the code that might be needed for any of the operating system configurations supported. Most of this code isn't used, and not even all the code loaded into memory is used. Some of the code isn't even for this mouse, to reduce the number of drivers the company has to support in every OS revision. The \"why\" is all about cost. Sure, the software could be made smaller, or more compactly installed, but that would cost more. Would you pay more for a mouse with a custom, smaller, driver? No, neither would anybody else. So you get a driver that works with any Logitech product and any operating system."
],
"score": [
9,
8,
4
],
"text_urls": [
[
"microsoft.com"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
asents | Why Wi-Fi signals are much weaker through walls, when compared to Cellular 4G and LTE. Also wouldn't it be better to use use Cellular signals when connecting to routers, so we would get better connectivity ? | Usually Wi-Fi can't go through single thicc wall, while cellular can go through buildings. | Technology | explainlikeimfive | {
"a_id": [
"egtrlo9",
"egtq7rm",
"egtqvak"
],
"text": [
"What you're asking about is propagation. Radio waves are just light, just like the light our eyes can see. The rods and cones in our eyes are simply radio antenna that can receive visible-light frequencies. The frequency of the radio wave received is a function of the antenna length. Anyway, different light has the ability to propagate through different mediums. Visible light shines through water and glass just fine, for the most part, but drywall and 2x4's, not so much. WiFi is in the 2.4 GHz band and can indeed shine through these things, like light can shine through a piece of paper. And it can shine through the atmosphere well enough, but will eventually be absorbed over enough distance, like visible light in a fog, it'll only go so far. And that's the point. Sure, you could use microwaves or TV broadcast frequencies or the 80 meter band to get far more distance (80m being overkill, you'd be sharing WiFi with most of the planet!), but that's not actually desirable. You see, there's only 1 electromagnetic spectrum. And this is a big fucking problem. WiFi works by all devices within radio range taking turns. That means every router, every hotspot, every laptop, cell phone, smart tv, tablet, and Bluetooth device (because Bluetooth is also on the 2.4 GHz band), are all trying to use the same spectrum, and they all have to take turns. It doesn't matter if you're on a different network. It doesn't matter if you're using a different protocol. When any one device transmits, all devices in range WILL RECEIVE that transmission. They look at the contents to decide if that transmission is for them, and if not, throws it away. So your neighbors are all taking up bandwidth you could be using. Again, it doesn't matter that you're on different networks, it doesn't matter how close you are to your WiFi router, it doesn't matter the signal strength, it doesn't matter that the thing tells you 54 Mbps or whatever, you're screwing with them, and they are screwing with you, and there's nothing (much) you can do to stop it. So if WiFi used a frequency with further propagation properties, then even more of your neighborhood would be saturating each other with their traffic. And the more devices there are, the more everyone who wants to transfer data has to wait to take their turn. This wait time is a contributing factor to \"latency\". Sure, when you do get your turn, and presuming it successfully gets received, it's as fast as light and at your WiFi's full transfer speed, it's just that you're not getting to transmit those messages as often as you could. And if multiple devices all transmit signals at the same time, all the receivers all hear noise. There's no way to determine one signal from another (without multiple antenna and triangulation and some advanced shit that just isn't in your cellphone). So that means everyone has to retransmit their messages, and do so in a way where they attempt to coordinate so that they all take their turn. And then throw in old wireless telephones, baby monitors, and microwaves, which aren't aware of WiFi or Bluetooth, and they just vomit their signals, or in the case of the microwave - straight up NOISE, all over the spectrum, and everyone within range suffers. And microwaves operate at 600-1000 W of power (compared to the 1 W upper limit if you hack your router with a 3rd party firmware to turn it up that high, typically it's limited to 600 mW). So everyone just suffers immensely until these devices STFU. By using the 2.4 GHz band, they can pack a lot of information in that high frequency, and due to its propagation, and legal limits to transmit power, you're basically limited to approximately your house. As it should be. Cellphones are a technology that require a very tiny amount of bandwidth individually, and has propagation of a few miles for a few milliwatts. So the carriers can put up a few towers every few miles and provide sweeping coverage of the whole area. But they, too, have to coordinate how parts of their spectrum are used and who gets to take turns. Ever go to a convention? Ever have good signal but you can't make calls in or out? It doesn't matter how good the connection is or how many towers there are, the whole network is saturated when you put 150,000 people within the same square half-mile.",
"WiFi signals are in the 2-5Ghz range - relatively high frequencies. Cellular signals are in the MHz range - relatively low. The lower the frequency, the easier it is for signals to pass through solids, because electromagnetic waves tend to be interfered with more by objects of similar width to their wavelengths. So a big radio wave has no problem passing through a foot thick wall, whereas a smaller WiFi signal will have trouble.",
"Yes it would be better to use the frequency that cellular providers use. Being able to is a completely separate problem. Because cellular frequencies travel way farther, if everyone and their brother had routers capable of doing this we all would be in interference hell. Also, the particular bands that Wi-Fi routers use are unlicensed (specifically the Industrial, Scientific, Medical band, or ISM for short). That means that we as a populace don't have to go out and get a license to use a particular slice of these radio frequencies."
],
"score": [
9,
6,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
asfs4u | How is using a password manager considered safe if you are throwing all your eggs in one basket? | Technology | explainlikeimfive | {
"a_id": [
"egtyzi1",
"egtz8lt",
"egu78vp"
],
"text": [
"Is it safer to hide your jewelry in different places round your house or in the big safe with the armed guards and alarm?",
"It allows you to make both the eggs and the basket much more secure than they would be otherwise. When you're creating individual passwords for each site you need to remember, people tend to do some or all of these things: * Use the same password for all sites, or various duplicates. If one gets hacked, the person has the password to ALL your accounts * Using simple passwords or variations like \"facebookmypassword\" and \"redditmypassword\" to help them remember different passwords for different sites * Otherwise using simple passwords, of limited length and complexity more vulnerable to brute force attacks Using a password manager means you only need to remember ONE password, which makes it easier to make that password much more complex since you only need to remember one. Like, Dkf295IsgrEAtAndp@sts@nElI5jumpingoverthesandwich. Similiarly, as you don't need to remember say, your reddit password to enter every time you need to log back in, you can make it as complex as you want (or even, completely randomized) and not have to worry about it being memorizable. But yes, if your master password gets stolen or cracked you're screwed.",
"A very important concept in security is the idea of a [threat model]( URL_0 ). In short, the real question isn't so much \"is this secure?\" as it is \"is this secure _against the specific threats I'm worried about_?\". There's a number of things we know are very real security problems for the average person: * Reusing passwords across multiple sites means that, if a site you use gets hacked, all the places where you've reused that password are potentially compromised as well. Password managers make it really easy to have entirely different passwords for all sorts of accounts. * Fake login windows trying to phish your Facebook/Google login (or any other service, for that matter) are a very popular attack as well. Password managers often have browser integrations and won't auto-fill those fake login boxes, which makes it harder to fall for them. * People suck at creating (and remembering) long, complex passwords. Password managers don't struggle with this at all, making all your passwords that much harder to guess. None of these assume that the attacker is targeting you specifically. The attacker is either creating a fake \u0010phishing site for you to visit, or attacking a service you use in some way. None of them require your own personal device to be compromised. Now, you are absolutely right — a password manager means putting all your eggs in one basket. But that \"basket\" lives in your device, so accessing your password manager data means being able to read files off your device. This is really not that simple with modern computer security! You don't type your password manager's master password into a website, you type into the password manager's app, so stealing that isn't easy either — the attacker must be able to log all the keys you press (either by peeking over your shoulder or installing some sort of malware — but now you need a way to achieve that). In the end, they got into your password manager, but they still don't know why, exactly, that's valuable — unless they have some reason to believe there's something interesting in there (e.g. if they know who you are). Stealing your passwords through your password manager requires an attacker that behaves in a very different way from the attackers the password manager protects you against, and, in general, somebody who's much more motivated to target _you_ specifically."
],
"score": [
35,
12,
12
],
"text_urls": [
[],
[],
[
"https://en.wikipedia.org/wiki/Threat_model"
]
]
} | [
"url"
] | [
"url"
] |
|
asg9ny | Why does turning a computer off and back on again fix the issue? Like doesn't it indicate a problem that will happen in the future? | Technology | explainlikeimfive | {
"a_id": [
"egu2wzl",
"egu3cze"
],
"text": [
"It depends on what the problem is, sometimes computers just have a hiccup where it isn't an actual issue and a restart will make the machine forget there was a problem.",
"Computers are enormously complex logic machines. They have a huge number of possible states, impossible to test completely. Some of the states are known to be good and work as intended while many are unknown and simply expected to function as intended in most cases. Some of those states lead to errors, unintended behavior that isn't what the user desires. Those are considered \"bugs\" or other kinds of malfunctions. When a computer is restarted it begins operation in a state which is known to be good (as it was thoroughly tested) and you are again able to use it to enter other states which may or may not function as intended. In some cases following a particular chain of logic will inevitably lead to the state of error as before which is a reproducible bug and as you suspected is an indication of the problem happening in the future. In other cases the particular state the computer entered was a fluke; perhaps a cosmic ray flipped a bit in active memory, or it was due to a particular interaction of data which is unlikely to ever occur again."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ashwlm | How is Netflix able to provide seemingly perfect subtitles to basically every show/movie on their platform and what allows them to do this so well? | Technology | explainlikeimfive | {
"a_id": [
"egufh76"
],
"text": [
"The people that make the show or movie write down the subtitles, from the script. They package that as a subtitle file inside the video file, and Netflix opens that up to show it to you if you enable subtitles."
],
"score": [
10
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
asi240 | how mobile finger scanner works? | Technology | explainlikeimfive | {
"a_id": [
"egvq545"
],
"text": [
"If you mean something like Touch ID on an iPhone then there is a crystal coverglass that protects the sensor and a metal ring to detect when a finger is in contact with it. When your finger touches the sensor, a ultra high resolution snapshot of the ridges and shape of your finger is taken, even the layers under the skin are measured (stops spoofing with fake finger). To take this \"image\", the sensor detects tiny tiny differences in capacitance (electrical charge) in-between ridges in your fingerprints, which makes up a full picture. These images are taken during the set up process, and then this image is turned into a mathematical hash, a one way operation, and stored on the phone. When you scan later to unlock, the \"image\" is snapped as you touch the sensor, the hash of that new image is generated and if the new one matches the stored one, the phone unlocks. & #x200B; TLDR; tiny sensor measures differences in electrical charges between ridges and bumps in your fingerprint."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
asirc9 | Why are websites so dead-set on showing you ads? Even if the user doesn't click an ad, does the website still make money because the user still saw it on the side of their screen? | Technology | explainlikeimfive | {
"a_id": [
"egumi2r"
],
"text": [
"Oh yes absolutely. they get paid. Digital ads get paid in two general ways: 1) Per click. Less common, but the site gets paid for each time a user clicks the ad on the page. This really isn't a great way to do ads, though it still is one way for sure. 2) Per view. This is overwhelmingly the most common way. Usually calculated in per 1000 views called \"CPM\". A website may get say $2 per CPM (that is $2 per 1000 views) of an ad. Shitty websites sell shitty ads and get shitty pays. Great websites with wealthy audiences, like say the Wall Street Journal, sell much more expensive ads. The actual economics of who gets paid what on ads are much more complicated than how I said it above, but the CPM \"per view\" method is the most common way ad digital ads are sold."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
asl40s | How do you control prosthetic arms and how does the prosthetic know what to do? | Technology | explainlikeimfive | {
"a_id": [
"egv2yjh"
],
"text": [
"Some nerve endings that were previously used to control that motor function may still exist. By monitoring for when these nerves go off, we can control a prosthetic arm that does the same feature."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aslsd5 | How was code written on the very first computers? | Technology | explainlikeimfive | {
"a_id": [
"egv6c1v",
"egv7i1o",
"egv7d69",
"egv6y1z",
"egvacuv"
],
"text": [
"Initially, not at all. The computer was a fixed purpose machine. You just built it to do the task you needed it to do. Think of say, mechanical calculators: you don't program them, you make their parts to perform the right function, and that's it. Later, you had machines you could rewire to change their functionality. Later, you can program a machine by toggling switches on a panel, or poking holes in a piece of paper. And then you start bootstrapping a programming language, where you write a program by programming operations by hand (switches or paper) that is going to use some input device to read something more human-friendly and turn it into something the machine understands. One of the first is an assembler, which is simply giving instruction numbers human friendly names. Rather than inputting \"00000101 00000001\", you write \"ADD AX,1\" which is way more human friendly.",
"One of the last computers that came without any firmware installed were the Altair 8800. So if you are interested you should look up some of its operating procedures. The computer came with a set of switches and lights on the front panel. These were not used as input and output for any software but were directly connected to the pins of the CPU. So using those switches and light you could inject data into the memory as if you were the CPU. Each switch would be one bit of either memory or address with other switches acting as control signals such as write or read commands. This allowed you to write code into the memory that could then be executed by the CPU. The first thing most people coded into their computers from a cold state were a loader for paper tape. The paper tape had holes in it and would be fed through a paper tape reader. The reader shined light through the tape which would activate a signal where there were a hole in the tape. So instead of flipping switches on the front panel the tape would generate the same signals so you could read data into the memory.",
"Early computers where programmed by manually writing machine code instructions directly into it's memory. URL_0 The Altair wasn't (by far) the first computer. But the video shows nicely, how old computers where programmed. The machines gave access (reading / writing) to the memory directly via a front panel. You where using switches to set the address of the memory cell you wanted to introspect. Little light bulbs (or LEDs) would show the value currently stored at that memory address. And an additional set of switches allowed you to store a new value at that address. All of that is in binary of course. To program the computer you use these switches to store machine code instructions directly in memory. Machine code instructions are just numbers. 42 may be the command to perform an addition, 43 may be the command for subtraction, and so on. These commands are hardwired into the processor. If it reads such an instruction from memory, it performs the associated operation. Once you done with programming the computer, you finally tell it the starting address of your program and make it go.",
"The first computers were a lot simpler than the ones today and stuff like \"drivers\" are a relatively modern thing. The earliest computers had everything hardcoded into them. You didn't re-program them as much as you rebuild them if you wanted them to do something different. They were more computing machines than modern computers. Programmable computers came a bit later though and they were still very simple. Some of the earliest programmable computer used punch cards to input the primitive programs that they executed. You wrote down your plan of what you wanted the device to calculate on paper than used a keyboard to punch it into the cards and then put the cards into the machine to follow the plan. Actual programming languages that allowed you to write programs as we do today came later still. It was all in machine code at first.",
"A long time ago you had to write code to work directly with the hardware, it was tedious and very specialized. Then they developed languages which people could manipulate and to solve more versatile problems. they had things like COBOL for businessmen and FORTRAN for engineers. Then a bunch of norwegians came up with the idea of a language fit for all domains, and they introduced the idea of a class in their language SIMULA. A class can represent just about anything, and that's was the beginning of regular programming as we know it today."
],
"score": [
36,
14,
9,
6,
3
],
"text_urls": [
[],
[],
[
"https://www.youtube.com/watch?v=EV1ki6LiEmg"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
asm3r7 | Why does your batteries performance drop if you leave it on charge while it is already fully charged? | Technology | explainlikeimfive | {
"a_id": [
"egvaaft",
"egvdm37",
"egvav45"
],
"text": [
"It doesn't. Not with modern batteries/chargers, anyway. The charger or the battery itself will have a circuit that prevents overvoltage/overcharging.",
"A battery's capacity drops when the chemicals in a battery react together in ways that aren't undone when the battery charges or discharges. These 'side reactions' happen more when the battery is fully charged, when it is fully flat, or when it is hot. Leaving the battery fully charged for a long time does allow some of those so-called 'side reactions' happen more than would if the battery is charged, disconnected, and allowed to discharge normally. In addition, when connected to power, the device and its battery can get hotter than it would otherwise. But, the difference is minimal, and so the convenience of just plugging it in when you go to bed and having it fully charged when you get up, is worth more to most people than the slightly better battery life from charging it most of the way before you go to sleep, unplugging it overnight, and topping it up when you wake up.",
"Batteries consist of two cells inside them with a wall between them that lets electrons through. Charging a battery causes electrons to move to one of the sides and be stored there until the poles are connected again. Charging a battery beyond the maximum induces extra energy to the battery and can cause chmical reactions to happen which can change the properties and degrade the quality of the components inside."
],
"score": [
16,
4,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
asmaqm | How does data compression work? | Technology | explainlikeimfive | {
"a_id": [
"egv951h"
],
"text": [
"Very simple ELI5 answer: Imagine that part of the file contains the string \"abbbbbbcd\". You could compress that to a6bcd. 9 characters down to 5. A 45% reduction. By using such techniques you can make a file shorter for download, and then the installation process expands it again. Another technique: If you have a picture of the sky, there are probably 500+ different shades of blue in there. By reducing that to 100, say, you need fewer bits and bytes to store details of the colour of each pixel. Which again saves space. Note the difference between these 2 techniques though. The first is known as lossless, because once you uncompress the file there is no loss of data. The second technique, known as lossy compression, results in a permanent downgrading of the quality of the image file. Which might become apparent if you wanted to print a really large version of it, or zoom in closely to the sky. You'd see that the area was a bit more blocky than before. & #x200B; One more point. Sometimes a 10 GB download doesn't actually contain the full 15GB of data, whether compressed or not. For example, you might download a program which, on installation, starts by creating a large empty database that will be used to hold data that doesn't yet exist. The code required to create a large empty database is tiny."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
asnv2l | How do fuel automatic shut off handles work? | Technology | explainlikeimfive | {
"a_id": [
"egvgsgd"
],
"text": [
"The ones in the gas pump? There is a free flowing air tube inside the handle. Any gas you pump into the tank, pushes air outward, some goes through this air tube. When gas gets high enough in the tank, it blocks this air tube, which triggers a trap in the handle, shutting off the fuel flow."
],
"score": [
16
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aspwkj | What is impedance and ohms and why is it so important to audio? | Technology | explainlikeimfive | {
"a_id": [
"egvuiet",
"egvtzi4"
],
"text": [
"Ohms are the unit of measurement of electrical resistance. Impedance is the resistance of a circuit independent of it electrical source, both in terms of static (Think DC voltage) current and Dynamic (think audio signal) current. & #x200B; How it relates to audio is in terms of power transfer. If you want to have the maximum amount of power transfer to your speakers (typically what you're trying to match in terms of impedance), you want the source impedance to match the load resistance (your speakers)",
"Those are terms of resistance for electricity, for overall circuits and specific resistors respectively. Basically, it affects the efficiency and quality of the electrical signals, which in turn affects the quality of the audio produced by those signals"
],
"score": [
6,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.