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
listlengths 1
1
| selftext_urls
listlengths 1
1
|
|---|---|---|---|---|---|---|---|
awxi74 | Why do you need at least an Nvidia pascal graphic card and a 7th gen intel cpu to stream 4k netflix movies with the pc app, but a smart tv without those components do it easily ? | Technology | explainlikeimfive | {
"a_id": [
"ehq60xo",
"ehpv11f",
"ehqb5os",
"ehpu8sl",
"ehq4c8k"
],
"text": [
"You don't need both as far as I'm aware; either one is fine. They're required because they implement certain copy protection / DRM features in hardware. Netflix sends encrypted 4K streams that require these features for decryption and display. If your smart-TV can stream Netflix at 4K it also implements these features using its own hardware.",
"It's still a pretty niche product even in 2019; the main limiting factor, unfortunately, is the software that interfaces with the digital rights management which prevents you from capturing the video and saving it.",
"According to the Netflix web site, for their Windows 10 app or MS Edge on Windows 10: \"Streaming in 4K requires an HDCP 2.2 compliant connection to a 60Hz 4K-capable display, Intel's 7th generation Core CPU or newer, and the latest Windows updates\" No mention of particular graphics cards. However, note that Netflix want to encrypt the data between your graphics card and your monitor using HDCP 2.2. Hollywood insist on this to ensure that you can't just record the video or stream it over the Internet. This is not really Netflix's fault, if they didn't use HDCP 2.2 then the movie companies would not let them have 4K movies. So you will need a monitor that supports HDCP 2.2 and a graphics card that supports HDCP 2.2. The Nvidia Pascal graphics cards were the first to support HDCP 2.2, but other graphics cards may be available that support it. For a smart TV, the display is built-in, there is no cable for you to hook into, so there's no need for HDCP. The CPU requirements are because there is a lot of video data to decode; you need a fairly powerful CPU for that. Depending on your graphics card, it may be able to do some/all of the decode on the graphics card, but that's more awkward to code for and more awkward to explain to end-users; just requiring a powerful CPU is much simpler for Netflix. It's simpler and cheaper for them to write the code, test it, and support it. If 4K becomes more popular in future, they will probably support graphics card based decoding at that time. Instead of a powerful CPU, a 4K smart TV will have a special chip that has the video decoder in hardware. This can decode the video much more efficiently - it uses less power and is much cheaper than a general-purpose CPU, but it can only decode that one video format and can't do anything else. For a TV that is a very good trade-off; for a PC the lack of upgradability and flexibility would make it a bad tradeoff. & #x200B;",
"Is this true, I did not know that?",
"Netflix locked 4k content behind several layers of arbitrary hardware and software requirements because they were paid to do so, not because of any technical reason. Last I saw, it was Kaby lake or newer intel only CPU, windows 10 and microsoft edge. 4k content with modern codecs is not that difficult to decode especially with some GPU support. This is a DRM lock in deal."
],
"score": [
7,
4,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ax0k78 | can human corpses undergo taxidermy and be preserved like animals? Why or why not? | Technology | explainlikeimfive | {
"a_id": [
"ehqghmg",
"ehqgeix",
"ehqjsqb",
"ehqgdy9"
],
"text": [
"Short answer, yes. Long answer, taxidermy isn’t quite what you think it is. The skin/fur of the animal is taken off the body. This is then preserved, and put over a wire frame and stuffed. The teeth are put in the mouth, and fake (generally glass) eyes are placed. You can do this for a human, it would be difficult, and the skin would be a different colour due to the preservation process. It works best with fur.",
"Yes. After all, humans are just another collection of cells like the others living beings on this planet. The reason you won't find may of them is that, besides it being creepy, the legal system will not allow it: There are lots of rules and regulations on what can happen with the human corpses before they are buried or burned.",
"Check out Gunter von Hagens. I saw his exhibition live. Was extremely interesting and well done.",
"Our skin is way too thin and prone to discoloration and cracking to taxidermy (i hate that taxidermy is the verb rather than taxiderm or something) Most animals which have to anchor fur also need thicker skin to do it and skin discoloration is hidden by said fur. Don't get me wrong, it has been done but it doesn't tend to last very long and generally looks awful."
],
"score": [
9,
6,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ax1l5h | How does the "I'm not a robot" work? | Technology | explainlikeimfive | {
"a_id": [
"ehqza0t"
],
"text": [
"A “robot” in this case is a macro programmed to do a certain task, such as “click here, type this, click here, etc.” So someone could make a robot that goes to a YouTube, clicks the “create an account” button, enters a username, password, and everything else, subscribes to T-Series, and then moves on to the next one. YouTube doesn’t want a bunch of fake accounts obviously. What a robot can’t usually do is identify pictures or weird words, or have human-like mouse movement. The ones where you have to enter text look weird so a robot can’t use software to identify what text it’s looking at. All the lines through the text mess it up. The ones where it asks you to “select all pictures containing a store front” or something, it has no idea what a store front is. That’s such a broad term, and with how grainy the pictures are it has no hope of figuring it out. The ones where you just check a box and it says “done” usually track your mouse movement or something. A robot will move the mouse in a PERFECTLY straight line, and stop right on the button, at inhuman speed."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ax2o0u | how does hacking in real life work? How exaggerated are hackings in movies compared to real life? | Technology | explainlikeimfive | {
"a_id": [
"ehqwy8n",
"ehqvhx6",
"ehr40uk"
],
"text": [
"Hacking in real life is starting a script to run a bunch of attacks, and then reading the paper waiting for the computer to \"Bing\". Then it's snooping around in the machine you've hacked, to see if there is anything you can sell there. Usually not, so it's on the the next computer, and the sports page. It's totally exaggerated in movies, because movies are supposed to be interesting (to get people to buy tickets). Actual hacking is hours of boredom, with a few interesting minutes in between. Nobody would pay to watch it.",
"Hacking is usually just trying to get around a password. In my experience, its like this: imagine there's a locked door, now you have 3 options: get the key, pick the lock, or find a window/backdoor/way around the door. Movies are *very* heavily exaggerated.",
"Real life hacking is not very exciting to watch and thus the movies and tv shows and many books tend to make up stuff they show instead. There are many different types of hacking. Social engineering may be the most likely to be depicted accurately in movies and tv. It is basically confidence artist and scammers trying to trick people into giving up information. This may look marginally existing and is easy enough for a non-technical person to understand. Calling someone up pretending to be their tech support to trick them into revealing a password or downloading something is about as basic as it gets. Other aspects are less glamorous and less easily understood. Showing a hacker writing a piece of malware is rather boring and not very different from them writing any other piece of software. You may get occasionally shots of some 'hacker' working on some program in movies and tv-shows but since actual programming environment tend to look boring they often substitute something more exciting look like that looks like it might involve programming from far away. Opening up a command shell changing its colors to black and green and running some simple command that results in lots of text output is apparently a favorite. The sort of thing you frequently see in movies where hackers race against time hitting key on keyboard in extremely fast succession to get in or even where dueling hackers fight against each other in real time is not really a thing. What also isn't a think is passwords that get guessed one letter at a time like an old mechanical safe lock. Tools that have progress bar to show you how close you are to whatever it is you are trying to achieve do of course exist, but the progress bars tend to be mostly cosmetics for endusers. No normal person who writes a tool just for themselves to use for a special occasion would include a progress bar instead of showing the progress in some way. Generally systems that you are trying to break into don't come with a nice GUI and helpful messages that conveniently tell those breaking in how well they are doing. Real hacking can be quite boring to anyone but the person doing it. Dramatizing it to make it look exciting from the outside is the only way to go really. It would be like trying to show the exciting world of forensic accounting to a viewer."
],
"score": [
5,
4,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ax5nqx | why a file name cant be \ / : * ? " < > | | Technology | explainlikeimfive | {
"a_id": [
"ehrc40t",
"ehrcasb",
"ehrcj3s",
"ehrp3yk"
],
"text": [
"Because those are all special characters used by othe purposes by the operating system. /\\ are directory separators : is used for the drive letter/device name in Windows * and ? are wildcards < and > are used for redirection symbols “ is used to allow spaces in filenames.",
"They can. For example, ext4 allows for all names except \\0, /, ., .. . However, assuming you are talking about a particular filesystem (FAT32?). There are two things to keep in mind that 1) Special Characters. Some characters tell your system to do something besides access the file system. (For example, in DOS ':' was used to denote drive). One simple way of handling these characters is to simply disallow their use in file names. (If they are allowed in file names, you have to define a way to 'pass through' anything that might be looking for special characters, such as an escape character. 2) Some of the older filesystems were defined before Unicode was standard. This means they couldn't rely on a relatively reliable character set and had to define an allowable character set for their implementation. For extremely simple file systems, this could just be ASCII",
"URL_0 Basically, they're characters that mean something to the programs and utilities that have to read filenames. Sort of like someone named \"None of your business.\" If they tell you their name, you won't recognize it as a name.",
"Lets say you have a file with the name \"great\\\\[movie.mov]( URL_0 )\". You save it in the folder C:\\\\movies. Now, many programs store filepaths as simple text strings. In this case, maybe some media player stores the location of this file simply as \"C:\\\\movies\\\\great\\\\[movie.mov]( URL_0 )\". When the player now tries to open this file, it has no way of differentiationg between the character \"\\\\\" as a part of the title and the \"\\\\\" as a folder level seperator. So it will probably try to open the folder \"C:\\\\movies\\\\great\\\\\" and look for a file named \"[movie.mov]( URL_0 )\". Since both these things do not exist, this cannot work. & #x200B; Thats why the \"\\\\\" is forbidden in file names in the first place. The other symbols have similar reasons."
],
"score": [
18,
6,
5,
5
],
"text_urls": [
[],
[],
[
"https://en.wikipedia.org/wiki/Filename#Reserved_characters_and_words"
],
[
"https://movie.mov"
]
]
} | [
"url"
] | [
"url"
] |
|
ax5w1s | On 1960s-1980s era TV shows why is 'outside' footage always more grainy? | I hope the person reading this knows what I mean... You watch any sort of TV series from the olden days (I'm from the UK so Fawlty Towers, Mr Bean, Blackadder Season 1 spring to mind as examples, I'm sure this applies to way more shows internationally too). The shots which are indoors seem more 'established' for lack of a better word. Smooth frames and clear picture, then they will venture outside and it just goes full grainy and what seems like much lower FPS too. Did they say "ok we are going outside, put the good camera down and grab the shit camera". Anyone who might know the reason for this? | Technology | explainlikeimfive | {
"a_id": [
"ehrd3bm",
"ehrgpgy",
"ehry0nz"
],
"text": [
"The outdoor footage was taken with a small, hand-held film camera that used smaller, lower-resolution analog film (16mm film typically).",
"Dad's Army was terrible for this. The outdoor footage looks twenty years older than the rest.",
"A lot of the time US shows would use stock footage when that would be cheaper to buy the rights to a shot or two than recreate the scene yourself."
],
"score": [
13,
4,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
axadua | How are our Phones so resistant to bugs, viruses, and crashing, when compared to a Computer? | Technology | explainlikeimfive | {
"a_id": [
"ehs7e48",
"ehs7hec",
"ehscbfq",
"ehst784",
"ehsicst",
"ehsanf3",
"ehsetqt",
"ehsctgx",
"ehs700t",
"ehs77j1",
"ehsje7l",
"eht025n",
"ehslkzi",
"ehtd24o",
"ehsaiq0",
"ehse034",
"eht6y3e",
"ehssiy1",
"eht8zh9",
"eht7w2h"
],
"text": [
"Bugs because the hardware combinations are more limited ~~then~~ than PCs Viruses? They're still vulnerable, less so because the O/S is very locked down always. The user *almost* never has \"root\" control of anything, unlike a windows system where if you have the password you can force through risky things to install if you have no idea what you're doing. \\*Also phone app stores are the only official way to install onto your phone, those apps are screened by Apple and Google. Sideloaded apps are far more rare and you have to work at getting that done knowingly Android and iPhone are both based off of Unix Like systems→Linux (droid)/BSD(apple) - There's no normal admin account that just gets to do whatever, everything is compartmentalized and locked down making only very rare exploits the likely vulnerabilities. Crashing? Same as bugs, limited combinations mean a manufacturer can ensure no weird hardware will cause problems and the OS doesn't have to be change much, minor driver differences at best. Most phones use the same family of chipsets for radios/wifi; screens. Samsung makes tons of shit for apple phones, they need each other. Until recently everyone uses qualcomm Sidenotes: 1. YES I know this isn't quite eli5 2. For all those grammar enthusiasts, yes I know the difference between then and than, I'm glad someone found a way to backhandedly comment my \"seeming\" intelligence yet complete feeble-mindedness due to a minor lazy grammatical error. Marvelous!",
"Extremely controlled environment. The Google/Apple/Amazon store only allows apps that are guaranteed* to work on the hardware their customers have. Those that have incompatible hardware cannot download the apps through the store. With great effort, you still can install the program manually and your phone will start crashing and bugging out. Computers can have any mix of parts that may or may not work as intended by the developers, and be running drivers that may or may not be updated. Since there's no universal store to buy all your apps from (and probably shouldn't be) developers have to just take a guess at what their user will be installing software on, and hope that they actually read what was and wasn't compatible. Nobody does, and the list isn't complete, so you run into bugs.",
"I used to be a mobile developer, doing mostly Android but also some iOS development. Apps on a phone are a lot more sandboxed than what you would get on your PC. An android app, for instance, does not have direct access to the storage spaces of any other app on your phone; as far as that app is concerned, using only its own power, you have nothing else on your phone except this app. No matter how hard it tries, it can't escape the little bubble that it's in. In order to allow the apps to talk to other parts of the phone, they use \"private methods\" or internal APIs, commands supplied by the OS to let apps access stuff. So, for instance, if your app wanted to access the camera on your Android phone, it would need to go through an API called Camera/Camera2. This is part of the Android OS, and written by Google. There are libraries that wrap this functionality up and make life easier for developers, but in the end all calls must go through that API. What this does is mean that the Android OS can essentially control everything the app does. This is why apps have to ask \"permission\" to access things like the camera; there is only 1 way in/out to the camera (that Camera2 API call), and it can be closed/opened using the little permission toggle. All other permissions work the same way. This is very different than Windows, where access to hardware is open to any application that can talk to the hardware drivers, and where any storage on the machine is accessible, as long as it isn't write protected or encrypted by the OS or some other means. Windows is the wild west, while your phones are highly controlled themeparks.",
"Who wants to write malware when you could just build an app where a user pays you for the privledge of giving you all their personal data.",
"While others have done a good job explaining why this is true, I'm going to point out that it's not as true as you think it is. **First of all, phones have plenty of bugs.** Apps have plenty of bugs. Phones crash occasionally. Users just don't notice as much! Mobile OSes started with power usage as a major concern and extremely limited multi-tasking. As such, their app development SDK insisted that 3rd party apps allow the OS to kill them at any time (to save battery) and provided a design pattern to allow \"tombstoning\". The app gets a brief notification that it's about to be killed and can write a little bit of state, then it's shut down. Well-designed apps write this tombstone data ahead of time in case they're killed without warning. When you \"switch back\" to the app, it may actually be started from scratch. It just pretends that it just picks up where it left off. When an app crashes or freezes on a desktop OS, the OS tries to give it a chance to resume working. This make it very noticeable when an app freezes, you get a spinning wheel, then the app UI disappears (and Windows gives you a crash notice). On a mobile OS, the app just crashes, restarts, and picks up where it left off. Sometimes, mobile apps get stuck in a crash-resume-crash loop, but are generally designed to count the number of start attempts and delete the \"resume\" data and start fresh. When a mobile OS crashes, it can do the same thing. Just reboot while the user isn't looking and pick up where it left off because the user isn't watching the individual app windows disappear. **Secondly, the virus game has changed since the days of Big Internet Worms.** There didn't used to be profit in malware, and so the goal was notoriety. Now, there's a shit ton of profit to be made in stolen user data, cryptocurrency mining, etc. The goal of modern day malware is to be unobtrusive and stay unnoticed, while the goal of famous Windows viruses was to do as much damage as possible. There is plenty of malware on phones, and the most insidious of all are apps that use 100% approved APIs and get the users to grant them permission to their hardware.",
"In addition to what others said, I'll add that most PC viruses spread via email attachments or by clicking bad links. Both are those are mitigated heavily on phones because an evil EXE file, for example, simply won't do anything on a phone - it literally cannot open.",
"Here's is a better ELI5: You have two houses. PC house is large, and has lots of big doors and windows. Many are unlocked, because the family living there wants to be able to go where they please, when they please, and do what they want. This freedom also means burglars can also get into the house easier if the family is not protected. Good families buy alarms systems and security guards (virus protection, firewalls etc). Android is a smaller house, and it's not owned by the family but just rented to them, and it was built with a lot more locked doors and windows the family can't open at all. Neither can burglars. The family gave up some freedom to go where they want and do what they want for more security. Now the family can rip out those locks (root/jailbreak) and get more freedom, but are again at higher risk. Apple house is pretty much a prison.",
"These days the malware and viruses are right out in the open like [Uber's \"God Mode\"]( URL_0 ) spying on you and [Facebook undermining a Presidential election]( URL_1 ).",
"Both Iphone and Android are based from Unix/Linux based systems. In short, these operating systems have much stricter rules on what is allowed to run, or who is allowed to run something. The user isn't even allowed to access most features themselves. In order to get a virus on a phone the way you could with a Windows PC, you would have to basically intentionally run the code on your own and possibly root/jailbreak your phone.",
"Phone OSes came about in a different era of architecture and design (and security awareness) than most OSes. Phone hardware is far more tightly controlled that that of a PC, which can support thousands of different options of each component. Even Android, which is relatively \"open\" as a specification, still has a specification that's far tighter than any PC specification. Even the software distribution is much tighter, as app developers have to submit their apps for testing and certification before they can be published. Yes, Android has \"alternative\" app stores, but those are largely overrun with buggy, virus laden software. There is no such control point for software on a PC.",
"You mean when compared to a PC running Windows and not Linux or MacOS?",
"This is an excellent question OP and I am going to try to offer a partial answer - on security in phones. For a start, any mobile device which has a CPU, RAM, an OS, and an ability to connect with other devices is at risk. This includes, cell phones, tablets, some cameras, some in car systems, etc. Those devices are not inherently resistant to security threats but are less of a target for some kinds of attacks (e.g. large scale malware and ransomware) because the people who initiate the attacks normally want to be paid and they can't make much by infecting or encrypting data on a phone (that is changing). As well, people on phones tend to use apps much more than Web services, and so they are less prone to downloaded malware and some other kinds of attacks. However, phones are much more prone to phishing (email, text, MMS) of all types as phone users tend to take security less seriously than they should and often respond to phishing attempts without thinking it over. The fact that most phones ship without security apps is a part of the problem, but the constant use of social media, texting, Cloud and other services from phones is really the bigger issue. People on phones often inter-mix personal data (useful to criminals for things like more phishing attacks, fraud, black mail, etc.) with work data (valuable to intellectual property thieves, corporate spies, nation state actors, etc.). Those people know that an average person is likely to have both types of data on their phone (e.g. business emails sent to the phone, docs stored from work via the phone, into a Cloud folder). So, phones are a target and they are under attack. Most of the time, attackers want your data. That is worth more to them than the phone (some exceptions apply). They are less of a target for **some** kinds of attacks but the threats that are on the rise include: * phishing (as mentioned); * Social engineering (convincing users to share sensitive or private information with another person through manipulation); * Surveillance of the user and their location/transactions/shared contacts, etc. via text monitoring, audio tagging, metadata collection, GPS, and a lot more. Much surveillance is done because the user agreed to terms of service without understanding them. Some is done by malicious actors though. * Malware (on the rise, including to take control of the phone for things like crypto mining) * Malicious WiFi hotspots (someone puts up a hotspot so phone users will connect, and then scans their communications looking for something they can steal/use). Computers are prone to the same stuff, except that most PCs come with built-in security features, especially under Windows 10 and Mac OS X and from Intel (another whole story) and a lot of users install and run Anti-malware software, a basic firewall, etc. to help secure the PC. PCs get hit far more often than phones and the numbers are staggering, so manufacturers tend to take security seriously (e.g. Microsoft). The protections in place on phones are unique though as follows: 1. Apple implements security in iOS (running apps in controlled and secure \"sandboxes\"), uses encryption widely to protect user data (e.g. in iMessage) and in hardware (built in encryption hardware, etc. In a nutshell, Apple iOS is a closed system and that makes it much harder for attackers to figure out the inner workings and then plan/launch attacks 2. Android, as an OS also forces apps to run in a controlled sandbox, runs a hardened kernel (the \"core\" of the OS). and support a bunch of encryption options (some run w/o user notice). Android is implemented on a ton of different hardware though and so things like device access hardware, file segregation, absence of bloatware, provision of security apps, and lots of other things is down the the phone manufacturer (e.g. Samsung) and some do security well (OnePlus) and some don't (you can google that :) 3. Both also provide tools to find lost/stolen phones, lock the phone, check that apps are signed and from a known source, block apps, protect OS files, etc Things start to break down if: 1. Users jailbreak their phone 2. Side load apps from unknown sites (i.e. not Apple or Google) 3. Don't use a password, facial recog., thumb print or SOMETHING to lock the phone 4. Share their device with others who may not be careful and diligent about security of YOUR phone and data All of those things put your phone at greater risk. A few tips on what you can do to improve phone security: 1. Set up a phone login and use a strong PIN or password or switch to biometrics...(at least 8 characters for a PIN) 2. Turn on phone tracing in case it is lost or stolen 3. BACK-UP important info (e.g. contacts) from the phone to a PC or into the Cloud in case you need to restore it later 4. Password protect any Cloud accounts with a strong (like 12+ characters) password 5. Install a password vault so you do NOT save passwords in something like Note or EverNote (bad idea and password vaults are free or cheap) 6. Install **all** vendor patches and updates, especially if they say \"Security enhancements\". This is a big issue in Android. Many vendors (looking at you Google) don't offer support for older phones. So, people who can't afford a new phone every 2-3 years are prone to newer attacks (because...no patches) 7. Install anti-malware apps and set them up to auto scan apps, incoming data, etc 8. Only install apps from reputable sources and check the security/privacy settings for all apps. If you are done with an app or have suspicions about how it is behaving (often hard to know), consider deleting it 9. Don't use social media apps on the phone. Seriously, they all suck and all (especially some in the news lately) take your data ALL the time 10. Read up on your phone's security features and apply those you understand (if not sure, read more) All of this applies to phones and tablets. Also, I know I didn't fully answer your question so it comes down to this \"more attacks on PCs, because they are data rich and may provide a pay day so vendors offer more security some built in and some you buy\"...but things with phones are getting worse and because phones are the gateway to much more (Cloud, remote to home, banking, etc.) they must be secured. Long post, but I hope this helps. :)",
"I'd come at this from the other perspective: who says they are?",
"It all comes down to the fact that Phones and desktops run different Operating Systems. I agree that a controlled environment for apps is a factor like others have pointed out. But it mostly depends on how well the vendors have tested their OS. The virus part heavily depends on how lucrative it is for hackers. And it can also be the other way round. For example I've got a Android phone with LineageOS and an Arch Linux Desktop. I need Anti-Virus Software for my phone, but not for my PC. And my phone crashes much more often than my desktop.",
"because they limit the user in what they can do. on an windows pc you can download and run any .exe you find. in android you have to specifically enable third party apps via hidden menu's before you can do that. on iphone thats basically impossible. this makes it way harder to deliver malicious apps because they have to go through an distributor instead of directly to victims. the operating systems are also limited in what they can do, a lot of niche things the majority of people won't use but are super powerfull.",
"They aren't, the systems are just more scrutinized Cellphone ecosystems are simply easier control in each phase. Take a peak: URL_0 Edit: typo",
"Because mobile OS (iOS and Android) were built in the 2000's with security in mind from the start. Unlike Windows and MacOS, where almost all users have permission to permanently modify the OS, mobile phones use the principal of least privilege [ URL_0 ]( URL_1 ), or, at least, a close approximation of it. In addition to restricting what users can do, mobile OS's restrict what applications can do. They can't modify other applications, they can't (easily) change the underlying OS. They're allowed to change their own data, and, with permission, change your photos, call history, music library, etc.",
"Simple: Simplicity of OS and hardware compared to a PC. Simpler: Walled Garden in the case of Apple products: the very thing many people complain about. **For Apple**, this also includes controlling BOTH hardware design and software design plus implementing critical technologies other platforms still don't really have like: * Apple designs both hardware and software so it has a level of control over how the device operates that Intel, Microsoft and Wintel vendors could only dream about. Similarly Android can never have the same control over behavior that Apple has because it also splits HW from SW. This is inherently more secure. * Apple can customize SW to match desired or designed HW features **it has designed**, and it conversely customize HW to match desired or designed SW features, Examples are the security/encryption processors and the motion processors that cooperate with the A-series CPU/GPU chips. Again, split-HW/SW architectures can only dream of this kind of control. So the security/encryption processor stores all thumb-prints, facial recognition and passwords inside of it - you can't hack it out short of opening the device, unsoldering the chip, using a lot of expensive equipment to destructively reverse engineer the chip and there's still a good chance doing that would destroy the data forever. iOS and macOS are designed to exploit this security processor now. * Use of a Unix-based OS - all networking was originally invented on Unix and similar minicomputer OSs, NOT on PCs - it makes a difference. Unix is generally more security and Windows historically shot itself in the foot by being \"backwards compatible\" which created most of the security problems. Android is a new OS so it's largely untested and Google isn't exactly the most trustworthy companies anyway when it comes to privacy and security. * Use of a particular variety of Unix called Mach which has a microkernel - the philosophy of which is minimize what is given privilege and put as much as you can into lower privilege user memory spaces. This includes stuff like file systems and hardware drivers. There are SOME kernel drivers but those are minimized and developers are strongly discouraged by Apple from writing kernel drivers. Usually you don't really have to unless you aren't a good programmer. * Sandboxing all apps so no app has direct memory access to any other apps memory or to kernel (OS) memory without going through special controlled interfaces. Every app lives in it own little virtual machine space where it has to ask \"Mother May I\" to do anything outside that space. * Declaration of what OS and hardware features you will use (disk, cameras, microphones, etc.) as part of the software BEFORE it's even accepted into the App Store. So you must declare what \"Mother May I\" questions you will EVER ask before start coding or submitting your app to the Apple Store * Having fairly tough guidelines on what can or can not be in the App Store. For example you can't just say \"I want to access all things all the time\" in the above credentials - that's not allowed and your App will be rejected if you try to do that. * Curating and reviewing every App to assure they meet the guidelines and rules Strictly some bad stuff that can still wiggle through but compared to Windows or Android or Linux, it's fairly minimal. This is part of why malware species are several orders of magnitude (1 order = 10x, 2 orders = 100x, etc.) higher on Wintel than Mac or iOS.",
"As someone who works in tech support for a cell provider my opinion is it's not that they are resistant, they are just way better at hiding it. Usually by the time any crashes or viruses become noticeable to the user the damage to the OS is already done and you have to wipe/reinstall the OS",
"In a normal computer, all your applications, by default, have access to all your files (and also the microphone and camera). Separating them is extremely rare, because, well, mainly because that's how it's always been. Under Windows and OSX, you also typically obtain your software by downloading it from the software vendors web site. On a phone, every app gets its own sandbox to play in (yes, that's actually the technical term). Also, the system will not let them access certain things like the camera without you giving permission. That means that even if you download malware, it can't really do much: It can't access data stored by other apps, access your camera etc. (Unless it manages to break out of the sandbox, which is not easy and requires an unpatched security issue in the sandbox.) You also can't (easily) download random software off the Internet - and putting malware into the Play/Apple store means that Google/Apple *might* find it before you can infect many users (though the reviews are no guarantee!) This makes the initial infection much harder, since the attacker can't just tell you an ad telling you to download the newest flash player. Additionally, the sandbox concept, combined with the fact that each phone has its own specific operating system and all phones of that type are exactly identical, means that it's very easy to know what the state outside of the sandboxes is supposed to look like. Thus, the phone can be built to make it very hard to change anything outside, making it harder for the malware to break out of its sandbox (and stay alive there even when the phone reboots). An operating system for a PC has to run on many different configurations of hardware, the user will install low-level drivers, and everything messes with everything, which makes it really hard to tell which changes were supposed to happen, and which ones were done by something malicious. Nothing technical (aside from the driver issue that could be worked around) stops you from building an operating system for computers that works like the one on phones, except that it will be unknown, nobody will use it because it has no apps, and nobody will write apps for it because nobody uses it... there are attempts to make this work with existing software, but there isn't enough demand for secure solutions to make them work well, and the ones that build them typically target the ultra-paranoid, which results in very secure solutions that are impossible to use for the average person, eat lots of resources, don't allow you to do many things, etc."
],
"score": [
11458,
785,
359,
124,
106,
76,
66,
63,
25,
25,
11,
11,
6,
6,
5,
4,
4,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[],
[
"https://www.theguardian.com/technology/2016/dec/13/uber-employees-spying-ex-partners-politicians-beyonce",
"https://www.nytimes.com/2018/03/19/technology/facebook-cambridge-analytica-explained.html"
],
[],
[],
[],
[],
[],
[],
[],
[
"http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=android"
],
[
"https://en.wikipedia.org/wiki/Principle\\_of\\_least\\_privilege",
"https://en.wikipedia.org/wiki/Principle_of_least_privilege"
],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axb9w8 | Why do smartphones seem immune to storage failures, whereas PCs frequently suffer from hard drive crashes? | Technology | explainlikeimfive | {
"a_id": [
"ehsd7jo"
],
"text": [
"solid state memory with a constant power source is pretty reliable, hard drives have a lot of moving parts that can wear out and fail. PCs tend to age 4 or 5 years before they are replaces, some much longer. Phones are typically replaced every year or two. So their systems are newer and less prone to failure."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
axbf9y | How does a smartphone determine its GPS position instantly, whilst a purpose-built car GPS takes minutes to acquire satellites? | Technology | explainlikeimfive | {
"a_id": [
"ehseig2",
"ehsm0bq"
],
"text": [
"Because (for most users) your phone is recieving and processing GPS signals 24/7. You car, however, needs to connect to the GPS sattelites each time you turn it on.",
"Your phone can self-locate using a variety of signals (GPS, mobile data and Wi-Fi in most cases) whereas a dedicated GPS unit typically only uses GPS satellites for location."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axbnh3 | How do laser sights work? it's either below or above the barrel, so if they're parallel then the trayectory of the laser and the bullet wont intersect, and if it's at an angle then they will but only at a certain distance right? so how does that work? | Technology | explainlikeimfive | {
"a_id": [
"ehsg3a1",
"ehshqtg"
],
"text": [
"While the LASER travels in a straight line, the actual bullet travels in an extended arc. There are generally 2 places along that arc where the LASER and the bullet would intersect. You can adjust your LASER to shift the point of aim at a given distance. Any further or closer than that calibrated space and the point of impact would shift either above or below where the LASER shows on target.",
"Laser sights are only useful at close distances because of both the offset (AKA: parallax) and because it's just really tough to see the actual dot at distance. As for the parallax, which you correctly point out, it is usually zeroed to the point of impact at 10-20 yards or so and the bullet impact will simply not be exactly on the dot when used at any distance other than the zero distance. Laser sights are not intended for extreme precision shooting; they are for quick engagement at close range."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axc5hu | How does YouTube have the space to hold thousands and thousands of videos? Even then having some of those videos in 4k which would take up a ton if space on a traditional harddrive. | Technology | explainlikeimfive | {
"a_id": [
"ehsjn41",
"ehslggv",
"ehsjqc7",
"eht9g7e",
"ehujtxh"
],
"text": [
"They use a ton of HDDs :D Basically they are held on a server farm. Which can hold petabytes of information. Though Youtube now has 100s of petabytes worth of info.. and youtube infrastructure is complicated! As youtube uses a pretty complicated distribution method for its data. when a standard person uploads a video, it only gets stored in the most local data center. this is why when you watch a video with very little views, it often buffers a bunch and takes forever to load. As view count increases, copies of the data are distributed to relevant data centers around the world. this is why ads and extremely popular content loads extremely quickly.",
"The simple answer is that they have a lot of hard drives . & #x200B; If you look and answer on the question from a 2016 the then then got 20 hours of video per minute, lets say that it is 100 today. There 4k video is a t a bitrate of 21.2 Mbps or 2.65 mega byter per second. & #x200B; There is 24x60=1440 minutes in a day You get 20x60x60= 72 000 seconds of new video per minute and at a rage of 2.65MB/s you get 1440x72000x2.65= 274752000 MB = 274752 GB = 274.752TB per day or 100 283 TB per year. If they used 4 TB drives that has the lowest cost per TB they need 68 per day or 25 000 per year. The cost of the dirves is below $100 per drive but even and that cost you only talk about $2.5 million. In practice the stor multiple size and redundant storage, computers to put them in and datacenters to put the computer in etc. But the estimated revenue of YouTube is $8 billion so the hard drives that need to storvideo is small compared to the revenue, & #x200B; It might sound like a lot but if you compare to the global PC market that was at 262 millions computer in 2017 that is 717 000 per day. So the number of drives google need per year is 1/28 the number sold in new computers per day. The sizes it not the same but it give a idea of the fraction of disks google might need. I would guess the there is many time the amount of storage needed for YouTube is unused in computers in the hand of consumers.",
"1 compression. 2 huge servers. Their staff is probably pretty minimal compared to a cable company because they don’t need to deal with end user hardware, and most things are automated. So hard lots and lots of hard drives.",
"Youtube has the space because it's owned by Google. Togther, youtube and Google bring in a ton of revenue, allowing them to build many gigantic server farms to store the tons of data that it stores. [This video is over 4 years old]( URL_0 ) so the technology has changed, but it gives you an idea of the sheer size of a Google data center.",
"On top of what everyone has said that they have big hard drive farms, they also expand those farms at ever increasing rates. They literally take in truckloads of terabyte hard drives everyday and install them."
],
"score": [
35,
5,
4,
4,
3
],
"text_urls": [
[],
[],
[],
[
"https://youtu.be/XZmGGAbHqa0"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
axcdtf | How do GPS store map data, calculate shortest paths, and overall deal with geospacial data ? | I have a project where I need to apply GPS concepts to graphs, and no article or video I found tackles the points I need to understand. So it'd be greatly appreciated if you guys could explain them to me. | Technology | explainlikeimfive | {
"a_id": [
"ehsmgw8"
],
"text": [
"Search online for A* (\"A Star\") algorithm. That's the one on which GPS are based on, with some differences. It's a shortest path calculation algorithm. If you think about it, a road map *is a graph*, with roads being arches and crossings being nodes. If you consider also other information such as speed limits and average traffic, it becomes a weighed graph."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
axcf55 | If phones can shoot horizontal video in horizontal mode, and vertical videos in vertical mode, why can't they shoot horizontal footage when being held vertically? | Technology | explainlikeimfive | {
"a_id": [
"ehslzyo",
"ehsm4r6"
],
"text": [
"The physical sensor that detect the light is a rectangle. So you use all of it in both cases. A larger sensor would be needed to shoot both in both direction and would add the ability so shoot a larger square video. & #x200B; This is how a Iphone X camera look when you take it apart in multiple steps and the rectangular senor is quite clear [ URL_0 ]( URL_0 ) & #x200B; A larger sensor would cost more and filming the other mode would be hade because you could only use a small part of the screen.",
"The camera is fixed in place on the phone, such that the aspect ratio (ratio between the height and width) matches that of the display. When you hold your phone vertically, the rectangular image that the camera captures is also vertical. If order to capture a horizontal image while being held vertically, you would need to be able to rotate the camera 90 degrees. This would add extra cost, complexity, thickness, and weight to the phone, as well as extra points for failure."
],
"score": [
5,
3
],
"text_urls": [
[
"http://www.i-runway.com/blog/wp-content/uploads/2018/01/iphone-x-rear-telephoto-camera-teardown-irunway-300x100.jpg"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
axdu33 | How the spacecraft docking to the ISS is slow while orbiting at high speed? | I was watching the SpaceX crew dragon spacecraft docking to the ISS. The spacecraft was slow while docking to the ISS. But at the same time, both the ISS and the Crew Dragon were orbiting at high speed. How does this docking process work? | Technology | explainlikeimfive | {
"a_id": [
"ehsvzz6",
"ehsweie"
],
"text": [
"The craft is slow relative to the speed of the ISS. As an example, drive on the highway at 65. Someone going 70 will appear to be going 5mph in relation to you.",
"The spacecraft and the station are both moving fast in orbit, but slow *relative to each other.* Think about cars on a highway. They might be driving at 65 mph (105km/h) but since they're all going the same speed in the same direction, they barely move relative to each other. You can drive at 65phm behind another car going 65mph, and the distance between the two cars won't change. Spacecraft docking to the ISS do the same thing. They match orbits and relative velocities so the spacecraft adjust its speed a little bit and slowly approach the station to dock, just like in my example, the second car can speed up to 66mph and thus would be slowly approaching the front car at 1mph."
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
axe4ie | How is certain hardware faster when electricity travels at the same speed? | A CPU or GPU is just a bunch of transistor gates in a really tight space so when you fit more transistors in a tighter space, it becomes faster. But wouldn't have no effect because electricity travels at the same speed and adding more transistors would have no effect. So what makes a certain component "faster" and how? & #x200B; Edit: Maybe I didn't word my post correctly, unless each transistor is in parallel and its own circuit (not sure if it is or isn't) then adding more transistors making the time for it to complete the circuit longer making it slower. So that means more transistors doesn't mean faster in theory. But manufacturers always focus on having more of them in a tight space. So why would more transistors make a CPU faster when it makes the circuit longer and adds more resistance? If the transistors have a circuit of there own it makes much more sense because all of those would complete at once but no one has mentioned that so i'm not sure. | Technology | explainlikeimfive | {
"a_id": [
"ehsyk5r",
"ehsy98v"
],
"text": [
"It’s not about the speed of electricity, it’s about the speed of decisions. Since computers all operate in binary, they make decisions by either saying yes (1) or no (0). These decisions are made by transistors (back in the old days it was vacuum tubes). Let’s for the sake of sanity say that one transistor makes 1 decision (yes or no) a second. Therefore to make 10 decisions it would take that transistor 10 seconds. Ok great, but that’s not good enough for me, so I buy another transistor. Not I can make the same ten decisions in 5 seconds. The speed of electricity doesn’t play a factor. The progression of technology is directly related to how many transistors we can fit on a computer chip. For more information, check out [Moore’s Law]( URL_0 ). It basically says that the size of a transistor shrinks by half every two years. Hence why computers used to be the size of rooms. Hope this helps!",
"You have to go back to how a switching transistor works: If you saturate the base with electrons, the flow of electrons between the collector and emmittor[sp] will start. If you make the size of the base smaller, the reaching of the saturation will happen earlier. As such the switch between a logical 0 and 1 will happen faster."
],
"score": [
6,
3
],
"text_urls": [
[
"https://en.m.wikipedia.org/wiki/Moore's_law"
],
[]
]
} | [
"url"
] | [
"url"
] |
axebbu | Why is HD referred to as 1080P, which is it's vertical resolution (1920x1080), while UHD is referred to as 4K, which is its horizontal resolution (3840 x 2160)? | I would've assumed the naming convention was standard but just now realized they name them opposite from one another. Why not call the latter 2K? Yeah, you'd be rounding but you're rounding to 4K as is anyways. Does this even have a legitimate reason behind it? | Technology | explainlikeimfive | {
"a_id": [
"eht03y5",
"ehszsh1"
],
"text": [
"It's just different naming conventions. \"4k\" sounds more marketable than \"2160p\". \"2k\" was actually the short-lived marketing name for 2160x1440 resolution. It's even more confusing because originally \"4k\" was specifically used to refer to 4096x2160 resolution, but over time TV manufacturers simply started using the 4k resolution to sell TVs which were actually \"UHD,\" which is the official name for 3840x2160. So now 4k refers to either one. I personally prefer to use the vertical resolution to name what resolution I'm talking about. \"480p, 720p, 1080p, 1440p, 2160p, etc.\" Is a lot easier to understand than \"DVD, HD, FHD, QHD/2k, UHD/4k, etc.\"",
"I work in the AV field, and my understanding is it’s strictly marketing. A “4K” display has the same pixel count as 4 “HD” displays, so I think the intent was to convey that. But they just wanted it to sound mo’ betta than what people currently have. I do not think the naming convention was established by an engineer. When professionals talk about resolutions we say “nineteen twenty by ten eighty at sixty” or “thirty eight forty by twenty one sixty at thirty” to avoid ambiguity."
],
"score": [
20,
7
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
axeefu | How does a force quit on an application work compared to pressing the close button normally? | Why do unresponsive applications respond to force close but not regular close? | Technology | explainlikeimfive | {
"a_id": [
"eht2g4o",
"eht0kad"
],
"text": [
"Basically think of it as getting a guest to leave your house. There are a few different ways to close a program. The most \"polite\" way would be to use the red 'x', or alternatively the file- > close button. This allows the program to save data and then close on it's own. Think of it as telling a guest \"It's getting kind of late, I ought to be going to bed\". The guest might respond with \"Okay, I'll get going then\". The guest (program) then wraps up whatever it was doing and excuses itself out. If the guest doesn't respond to this, (or the program doesn't close) you might resort to the \"end task\" button on task manager. This basically equates to saying \"you need to leave\" to your guest. It might hurt their feelings, but it allows the program to close without corrupting anything. However, if that doesn't work, you may have to resort to the extremes. If you go to the processes tab, right click on your program, and click \"end process\", it stops the program instantly and stops running it without question. This basically equates to throwing the guest out of your house by force. This might cause some problems, as you may have corrupted any data that the program was accessing (or your relationship with your guest). If a program stops responding, that normally means that it has crashed or it has hit a bug (or perhaps your guest has had too much liquor?) This means that the code that they wrote to gracefully close it won't work, as the program has essentially stopped running. Since the red x just asks the program to leave, it won't really respond to that. (drunk people don't have much logic). So, you must resort to yeeting your now incapacitated guest out of your place of residence. (the force close button) I hope that put it in more understandable (and memorable) terms. Edit: Ooh, my first gold! nom nom!",
"Ultimately the difference is how the operating system, like Windows or macOS, goes about *asking* the program to close. When using the “x” or close button, your computer is asking nicely that the program wrap up anything (like saving edited documents) and exit. If the program is unresponsive, this ask won’t be handled. When you force close, your operating system unmediated terminates the program without asking - because it’s not asking it closes immediately but there is a slight risk of data loss if there was any unsaved edits to files that are open. Source: Computer and Software Engineer"
],
"score": [
27,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
axewvu | Why is it that when you look at a calculator head-on, you can see all of the numbers on the display, but when you look at it from a side angle some parts of the numbers disappear into the background? | Technology | explainlikeimfive | {
"a_id": [
"eht4tl5"
],
"text": [
"LCDs work on the basis of the polarization of light. There are a few layers in a LCD: Two polarizing filters, 2 layers of glass, and the liquid crystal in the center. Polarization is when you can get all the rays of light lined up in rows using a filter or some other method. Once all of the rays are aligned, they will only pass through another polarization filter if they are in the same orientation. You can see this if you have two pairs of polarized sunglasses. Try putting one lens over the other, and then rotating one while keeping the other stationary. You will see that in a certain orientation, you can see through them both, but when you rotate one 90 degrees, they become completely opaque. The LCD is arranged like this: \\-------------------- Polarizer film Glass Liquid Crystal Glass Polarizer film Mirror (or backlight) \\-------------------- & #x200B; When the light passes through the first polarizer, it gets aligned to one orientation. Then, it passes through another polarizer and to the bottom, where it bounces off a mirror. Then, it passes back through the Liquid Crystal, and out the top through the polarizer. The liquid crystal has the interesting property of being able to twist the orientation of the light. The glass is coated with a transparent coating that is electrically conductive. This coating is masked to form the shape of the segments on the display. When energized, the liquid crystal rotates all the light going through it, which is then blocked by the polarizer since it is now oriented differently. However, a side effect of the polarized light is that it likes to travel in a straight line. If you tilt the display, your eyes no longer see the polarized light because it is not pointing in that direction. It's rather hard to explain in only text, so if you want an illustration, the wikipedia page on LCD displays has a nice diagram illustrating this. & #x200B; Edit: crappy wording, fixed."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
axh2ag | How does an electronic device know the percentage of the battery? | Technology | explainlikeimfive | {
"a_id": [
"ehtl936",
"ehtjqnm"
],
"text": [
"The voltage is not constant as the charge drops. The voltage steadily drops as the charge does, until it becomes insufficient to power the device. The device will typically have a voltmeter to determine how much the charge has fallen and how much it has left before it stops working.",
"Voltage can be thought of as electric pressure, when the battery is used this pressure drops Like letting the air out a balloon by using electronic components and software with some mathematical formulas they can make an assumption of how much power is left based off how much pressure is left"
],
"score": [
15,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axhv0j | Why do images' data storage sizes decrease when saving in MS Paint without doing anything? | When opening an image in Microsoft Paint and pressing CTRL+S such that it saves in the same format, the size of the image in the bottom left corner decreases. Saving without doing anything can continue to decrease the size until the image reaches a point where saving can increase or decrease the size by half an MB or so. Why is that, considering that the image shouldn't technically be altered? & #x200B; I don't think it's a glitch, so that's why I'm asking here. Please redirect me to a more appropriate subreddit if there is one. | Technology | explainlikeimfive | {
"a_id": [
"ehtrapq",
"ehtrazy",
"ehtsj9g"
],
"text": [
"Interesting. Some image formats, like JPEG, are inherently compressed file formats. MSPaint might be compressing the image even more. JPEG is lossy compression though, so you’d expect to see a slight decrease in image quality on each save. PNG is lossless compression, but file size may decrease. Here’s what you can do to test this further: BMP is a fully *uncompressed* file format. You should not see any file size change upon save with this format. Try it out and see what happens.",
"It has less to do with Paint and more with the file type you save it as. Images can be stored in different formats. Draw something in paint then try to \\- save it as a .png file \\- save it as a .jpeg file and you'll notice a file size difference even though you're saving the same thing. & #x200B; Generally speaking, if the image has a lesser number of total colors and large blocks of color chunks or a lot of contrast (sudden changes in color), .png files tend to save them more efficiently. For real world images, with less contrast and large variations with a lot of colors, .jpeg does better. & #x200B; Its likely you had an image belonging to one of those types and used paint to save it in a more efficient format.",
"It would depend on the particular image format, but I'm guessing what's going on here is that Paint is compressing the images. A format such as bitmap is quite simple to understand. In a bitmap file you have a bit of information about the file itself, and then the location and colour of each pixel. Whether you have an enormous HD picture, or a small icon, you can always retrieve exactly the image as it was when you saved it, it's just a grid of pixels. This is quite wasteful though, if you have 50 black pixels in a row, you might say \"here are 50 black pixels starting at x\" rather than explicitly recording where each one is. You can still find them exactly as they were, but using potentially much less disk space. Such compression is *lossless* because you don't lose any information. PNG is like this. An alternative is *lossy* compression, which may be similar in spirit to a lot of lossless formats, but you don't necessarily care about preserving the image exactly. JPEG is clever, in that for most purposes you don't generally sacrifice much the identifiable bits of an image, but for small details - like text - there are often noticeable compression artefacts. If you can continue to save an image like this, Paint is probably applying some lossy compression. You are more than likely losing some information every time."
],
"score": [
4,
3,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
axjdbk | A vast majority of cords and cables are black. Why? | My phone charger cable is black, my aux cable is black, my hard drive cable is black. My coffee machine cord is black, my toaster cord is black. Black, black, black, black. Why is it? | Technology | explainlikeimfive | {
"a_id": [
"ehtx0ah",
"ehtwxo6"
],
"text": [
"There are several reasons for this. Black is usually a color that can be hard to spot. So no matter the color of the surrounding area it is safe to use black to hide the cable. The best is of course to have the cable in the same color as the surrounding area. Secondly a lot of plastic include bromide as a fire retardant in order to comply with fire safety guidelines. But bromide tends to turn yellow when it is exposed to light over a long time. But with black you do not see that the plastic changes color. And finally plastic degrades when exposed to strong UV light. However the black color prevents the light from penetrating into the plastic. So any cables that might be exposed to sunlight needs to be black in order to not get damaged.",
"It is not a bright colour and doesnt attract your attention which somewhat increases the aethestics of what ever appliance is in question because you dont notice the cord as much"
],
"score": [
40,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
axl0xf | How does my phone track my steps? | Technology | explainlikeimfive | {
"a_id": [
"ehu7lyy",
"ehud185",
"ehub4zr",
"ehuc4us",
"ehu9x54"
],
"text": [
"Your phone has a three-axis accelerometer in it, which reads the force of acceleration in three orthogonal directions (think up/down, left/right, back/front although these designations vary with regard to the phone's orientation in the world they're always 90 degrees from one another). When you make a footstep, it creates an impact event - a high frequency sudden shift in acceleration. The phone detects these impact events and marks them as footsteps. If you're also detecting how far you travel, further signal processing is used to determine the zero-velocity point to pair with the impact events to determine how far you've travelled. Gyroscopes on the phone can then determine which direction you've traveled. If your application is really sophisticated, it will also 'fuse' this information with GPS location data to allow constantly re-calibration against sensor drift. In terms of accuracy, it's fairly accurate unless something is specifically interfering with the sensor readings. For example, if you're riding on a train, the rumbling of the train can sometimes create impact events that simulate footsteps. There's no way to perfectly detect footsteps, but decent signal processing can reduce the error rate down substantially.",
"It isn't tracking actual steps, but sudden changes in direction the phone has moved. The pattern of those changes is predictable, so phone are able to distinguish steps from other types of movement. It is not perfect & can be faked, so it's not too terribly accurate, but enough to get the job done.",
"Imagine that in your pocket, your phone jumps a little every time you land a step. This tells it that you just took a step, and it counts one more.",
"> also, is it even accurate? I drive a rough terrain forklift for a living and the bumpy ride definitely counts steps I didn't take",
"A mechanical pedometer is easier to visualize. There is a weight on a spring. Every time you take a step it bounces and counts one step. The phone just does that electronically without any moving parts. I'm just annoyed that it mistakes my fairly vigorous ice skating for a very slow walk. Just not as much impact!"
],
"score": [
127,
10,
6,
5,
4
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axldbp | what are backlinks in regards to SEO and why are they such a big deal? | Technology | explainlikeimfive | {
"a_id": [
"ehu8f0b",
"ehudo97"
],
"text": [
"Let’s say your website is URL_0 . You want to rank higher on Google. SEO specialists might say that you need more backlinks, or links that click out to ESPN on other sites (referring sites like URL_1 or even Reddit). Google searches for how many backlinks you have (or other sites that link to your content) and rank you on it. It’s important because Google thinks that the most relevant content will have the most people talking about it (or referencing their content).",
"They are links from other websites to your site. They are a big deal because if somebody else thinks your content is important/interesting enough to link to, then Google views that as a strong endorsement of quality and value of your content."
],
"score": [
5,
4
],
"text_urls": [
[
"ESPN.com",
"nfl.com"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
axlhb5 | As you remember there were polyphonic melodies in first cell phones. Why they couldn't play normal sound, was it that hard to have that technology in late 1990s and early 2000s? | Technology | explainlikeimfive | {
"a_id": [
"ehual8m",
"ehufyfr",
"ehuhh5s"
],
"text": [
"Instead of recording the actual waveform of the sound, polyphonic melodies are like sheet music: they just contain a list of notes to play. This information is stored in a file format called MIDI (Musical instrument Digital Interface), and typically includes information like the pitch (which note it is, e.g. 'middle c'), intensity (how loud the note is), start time and duration, etc. Storing the information this way takes up a lot less storage space than the actual sound would. For example, a one-minute MIDI file might be 10KB, while a one-minute sound file might be 10MB. Since old phones like had very little storage space, only MIDI was small enough to fit.",
"This brings back lots of memories. Axel F. URL_0",
"By “normal sound” I presume you mean, recordings. Like people have said, they used MIDI, what they didn’t mention is that this is actually playing a synthesiser. I don’t know exactly what one, but it sounds like it’s a square wave oscillator. This can be done with electronic circuitry, which requires no memory, triggered by midi (or something similar), which requires very little memory. Recordings of “real sound” are usually made with something called PCM (pulse code modulation). A standard for this is CD quality, which is sampled at a rate of 44.1kHz (44100 times a second) and has a bit depth of 16 bits (~65,000 possible values). Why it needs to be that way is something called Nyquist-Shannon theory. Basically, humans can hear between 20Hz and 20000Hz, and to accurately represent the waveform of all of those points, you need at least 2 samples for every possible frequency, which means you need 40,000 (20,000 x 2) samples per second. 44.1k because, better to be safe than sorry. Now, if you’re sampling something 44100 times a second, and it can have ~65000 possible values, you’re going to need memory. A lot of it. A standard 3 minute song encoded in 44.1k 16-Bit PCM Audio is about 30 megabytes. If it’s compressed into a low quality mp3 it’s still about 3 megabytes. I can’t find the exact amount, but earlier mobile phones like the Nokia 3310 and 3510i have memory that is listed in terms of a whopping “10 saved recent caller IDs” and “500 calendar notes”. That doesn’t exactly scream the megabytes needed to store even poor quality “real sound”. So, the answer is, they don’t have enough memory to store audio."
],
"score": [
10,
4,
3
],
"text_urls": [
[],
[
"https://www.youtube.com/watch?v=Qx2gvHjNhQ0"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
axms2v | Why can you plug an (AC) electical plug backwards in to a socket and it still works? | Technology | explainlikeimfive | {
"a_id": [
"ehuit28"
],
"text": [
"AC stands for alternating current. The flow goes one way, then the other way, really fast. The device is receiving alternating no matter which way you plug it in."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
axnk0o | What is Natural Language Processing | Technology | explainlikeimfive | {
"a_id": [
"ehuqjtp",
"ehv348h"
],
"text": [
"When you are very, very young you learn how to speak. You start with \"mama\" and \"dada\" and as the time goes by, your mind understands more words, as well as the relationships between them. Then you go to school and you learn about things like \"grammar\" (*how* to say things) and \"vocabulary\" (*what* words you can use). By the time you graduate, you (hopefully) hold a relative mastery of the rules that dominate your language. Sometimes and for many reasons and applications, we want computers to understand natural language. The good thing about computers is that they can calculate way-way faster than you can. The bad thing is that the human way of learning natural language is very difficult to replicate on a computational model. Humans are really good learners (until the elections come - hehe). The discipline of computer science and linguistics (you may also throw AI in there) that is concerned with the creation of computational models that process and understand natural language, is called Natural Language Processing or NLP. These include: making the computer understand the semantic grouping of words (e.g. cat and dog are semantically more similar than cat and spoon), text to speech, language translation and many more.",
"Natural Language Processing (NLP) is getting computers to use and understand human language and speech, such as English, French or another \"natural language\". For example: * Any voice recognition, speech synthesis, or question answering program like Siri. You can speak to a computer and it understands your voice. * a computer program that reads company reports or health records in plain English and produces numbers from them (e.g. profit this quarter). * if you upload your CV/resume to a job site sometimes it will automatically get your name and past employers from the document and fill out a form, even though different people could have formatted the document differently. * Google Translate * a search engine like Google which gives you documents when you type a word into the search box. Note that when you search for *cat*, Google will give you documents containing *cats* and even *feline*. Note that for the last example, an engineer will have given Google's software the information about English synonyms and English plural patterns. Natural Language Processing is a kind of Artificial Intelligence. If you want to build an NLP program you can start writing rules like \"ignore an s on the end of a word\". This is the old school way of doing things and it's called the \"rule based\" approach. However the more advances techniques use machine learning, where you program your computer to learn patterns in English. If you do this you could even write your program only once, and train it to work in many human languages."
],
"score": [
6,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axr2yz | Why does turning the volume down on my phone and up on my car give a cleaner signal at the same volume? | This is kind of a weird one but if I put the volume on my phone to full blast, I get static through my aux to tape. However, if I turn it down a couple notches on my phone and turn it up in my car, I can go even louder than before while still getting no static. What causes this? | Technology | explainlikeimfive | {
"a_id": [
"ehvhh7j"
],
"text": [
"You are overdriving the output of the phone OR the aux-to-tape converted (the latter most likely), essentially pushing the circuitry beyond its limits. When you lower the output you put the circuit back into operating range and you can then cleanly amplify the signal using the car stereo."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
axrz14 | Why does it take so long to download and interpret Black Box info after a plane crash? | I realize it can take time to find the black box. But why isn’t there a computer program that hooks up to the BB and acts like a simulator? All the data is there. Why can’t they plug it in and watch a recreation of what happened immediately? | Technology | explainlikeimfive | {
"a_id": [
"ehvoi1q",
"ehw6l28",
"ehwbaha"
],
"text": [
"The “black box” isnt a single system, its made up of separate recording devices through the aircraft. It doesnt record EVERYTHING, only the Time, Engine specifics and altitude, the other records cockpit voice and conversations. The data recording systems on aircraft flights saves burst data, meaning it only starts actively storing information on systems during burst periods of input, as soon as altitude. Flight pattern. Engine function or flap position starts changing quickly, like a problem has occurred, it begins capturing the movement and data. It doesnt record every aspect of the flight or its systems. Only those that are changed via pilot manual input basically. Its like trying to take a 30 second movie trailer and building the entire movie from it. Edit: spelling",
"So much bad info in here. On commercial planes, there's 2 'black boxes' (actually painted orange, not black, but the name stuck): the Flight Data Recorder (FDR), and the Cockpit Voice Recorder (CVR). Optionally there's a 3rd device, the Quick Access Recorder (QAR) but this is not always used. These recorders are constant recording devices, recording up to thousands of data points. On the CVR, there are multiple high resolution audio channels in the cockpit, including each flight position and general cockpit noise. On the FDR, things are also tracking aspects of the flight, engines, attitude, etc. Why can it take so long to read out? Because they are recovering vital data after a massive impact that usually shreds the plan to bits. The boxes have to be found first (e.g. for the recent Amazon flight, they were buried in mud, but they could also be deep in the ocean, or in supper-difficult terrain to access). Once found, they have to be very carefully preserved and shipped to properly equipped research labs (only a handful in the world). When the devices are relatively unharmed, and assuming modern solid-state digital recordings (versus the ancient tape recordings), they are usually downloaded, read, and validated within a couple of days or arrival at the lab. But then they have suffered a massive impact (e.g. over the defined 3400G limit, or 1100C fire for 30 mins), then the lab experts often have to extract individual data chips and then reconstruct data by very low-level recovery techniques. When you put it all together, these guys do an awesome job, and the lessons learned from the last minutes of a stricken flight make the skies safer for all of us.",
"If they find the black box in tact they can get the data pretty fast. But interpreting it isn't that easy. There isn't enough data to build a complete simulation of what happened. And even if there were it wouldn't really be cost effective to develop a simulator program to reliably make sense of it. Easier to just parse it and reconstruct what happened manually. There are other systems aside from black box that they recover data from. They aren't necessarily water/damage proof. I work for a company that makes engine control units. If the unit is in tact we can pull the data off of it with our normal engine maintenance software easily. But in the past they've brought water logged ECUs to us, and we've had to spend weeks recovering the data from them. We have to pull off the memory chips then come up with some hardware/software to be able to recover the data from them. We don't have this equipment laying around because it happens so seldom. On top of that, even if you can get all the data immediately and it seems obvious what went wrong you're still going to want to finish your investigation and account for all factors. Does the physical damage agree with the aircraft data? If the problem was an engine failure, were there other factors that led to that engine failure? You're going to want to have all the answers before you start publicizing your findings."
],
"score": [
24,
7,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
axthjh | How do portable batteries know when to give or receive charge? | This battery I have uses the same USB C port for charging the unit itself as well as charging other devices. How does it know what mode to be in? | Technology | explainlikeimfive | {
"a_id": [
"ehw3hz3"
],
"text": [
"The electrons will go where the voltage \"forces\" them to go, much like water falls or flows where gravity pulls it. So if the battery is the only generator of voltage, then the chemicals inside will react and produce electrons that will go through your device. However, if you connect a \"more powerful\" source of electricity, like for example a USB 5.0 V to a (normally) 4 V battery, the electrons go INTO the battery (because there's a 1 volt difference) and force the chemicals inside the battery to \"un-react\", thereby \"charging\" the battery. Basically to charge a battery you just connect a slightly higher voltage to it."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
axxe33 | How did Stephen Hawking talked even though he can't move a muscle? How did the computer knew what he wanted to say? | Technology | explainlikeimfive | {
"a_id": [
"ehwphh0",
"ehwpeqp"
],
"text": [
"He used very subtle muscle movements to control the computer. The computer would go over a list of letters/words and Hawking would move his muscle whenever he wanted to choose the current letter or word. Towards the end of his life it would take him up to a minute per word. Any interview you see of him is either heavily edited to remove these long pauses, or his entire talk was pre-recorded (that's how he gave lectures).",
"It didn't read his mind. He used a muscle in his cheek to trigger a sensor which moved a cursor across a screen of letters, words, and stock phrases."
],
"score": [
20,
7
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
axyh96 | Why do modern cameras have lower (~12) megapixels as compared to older cameras? | I thought it was always better to have 'more' megapixels on your camera/phone to get a good picture. My previous phone had 21 mpx as compared to my current which has 12 mpx, still my new phone clicks better pictures as compared to the 21 mpx phone. | Technology | explainlikeimfive | {
"a_id": [
"ehwvt3o",
"ehwvgoy",
"ehxdqr8"
],
"text": [
"When I took a digital photography course in college, probably about ten years ago, it was explained to me like this: It's less about the absolute number of megapixels and more about the ratio of megapixels to the size of the photo sensor. The size of the sensor is more indicative of image quality than the number of pixels, but \"12.5 megapixels\" is more marketable than \"big ol' photosensor.\" It's easier to compare 12 to 10 and say, oh I know which one is better. This is what started the megapixel hype. We are probably starting to see this die down a bit as camera components become cheaper and image capturing software becomes more powerful.",
"Because we've got beyond the stage where more pixels would give us a better image. The megapixel wars are over, thankfully; and now cameras fight it out over better looking pictures.One thing that will give better pictures is *larger* pixels on the sensor, and the first thing you need to do to make pixels larger is to have less of them.",
"Increasing the resolution of image sensor in a phone camera beyond about 12mp doesn’t really lead to significant improvement of image quality because the lenses on those cameras are not good enough to actually produce an image with more than 12mp of detail. At the same time having lower megapixel count has some benefits like faster read speed and easier processing. Manufacturers always knew that but until some point they were forced to put higher resolution sensors in their phones for marketing reasons. That’s because until some point consumers really believed that megapixel count was indicative of overall image quality."
],
"score": [
9,
6,
5
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
axyjqn | Why do new Phones cost more and more but don’t seem to be that „new“? | Technology | explainlikeimfive | {
"a_id": [
"ehwzubv",
"ehwxt1d"
],
"text": [
"Very simple: because people are willing to pay for it. Top-level phones also have a very nice position right between life necessity and luxury status symbol. On the one hand, for the amount of entertainment and business utility it provides, it's understandable for people to spend amounts that are similar to a laptop. On the other hand, $1000 is cheap for a luxury product. The amount of interaction (be it through Instagram likes, or \"Is that the new iPhone?\" questions IRL) a new iPhone gets, is a lot higher than similarly priced watches, jewelry, etc. and it's definitely a lot cheaper than a nice car.",
"when a technology gets older (mature) changes (innovations) becomes relatively smaller because the technology gets more developed. for example 10 years ago the smartphone was a breakthrough and innovations were large and fast but now the smartphone is pretty much developed so there is less to add in a new phone untill there is another breakthrough"
],
"score": [
6,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ay6ffh | Why screens are hard to read outdoor? | Not only sunny days, cloudy even overcast days. It's just hard to read screens clearly outdoor. | Technology | explainlikeimfive | {
"a_id": [
"ehyovgx",
"ehykt0l"
],
"text": [
"Bright sunshine can exceed 50 & #8239;000 lux whereas bright lighting inside is typically more like 500 lux. Our eyes are amazing enough to deal with this factor-of-a-hundred difference but consumer display technology is not.",
"The Sun is very bright. Much brighter than the display technology available for signs. To over power the Sun would take a powerful laser on a sign in the middle of nowhere. What could go wrong? Everything!"
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
ay6hf5 | How were video game cheats/trainers written? | Firstly, I haven't played video games for years and have no intention of cheating on any video games. But I picked up programming (C# and Python) 3 years ago and wondered how were online game cheats / offline game trainers written in the programming perspective. | Technology | explainlikeimfive | {
"a_id": [
"ehynbcd",
"ehysbjf",
"ehyooc7"
],
"text": [
"Well it involves memory for the offline. Basically it is easier to do in c++ , but since I suck at c++ I did it in c# pretty much you can hook into the game that is running. Then you memory dump what the game is doing in ram. Searching for certain numbers you can go ok these memory addresses all have three which is my number of lives. Die once then search for 2 on those same addresses. Process of elimination. Ok so this memory address hold my number of lives. Right code to monitor it and if it changes make it back to 3 again. Tada infinite lives or whatever. Aimbot and such are a bit harder and I never got that far. Online it's a bit harder as you usually have to compensate for anti cheat. Which I have no idea how to get around. And also you cannot change stuff that is stored server side. I tried to do above in diablo 2 back in the day with my life and the server would always reset it back to it was. However you can inject code into the communications stream to do stuff once you figure out how to read the packets the game sends. This can let you do other things and why people making multiplayer games should never trust the client. Too easy to manipulate data. Anyways just what I did messing around a bit. I only really did trainers for single player games beside the d2 thing so this was a while ago.",
"It boils down to figuring out how the game communicates with memory storage, and finding areas in that communication which are vulnerable to manipulation. Offline games are stored on your machine. So if you figure out where in the physical memory the information is stored, you can rewrite it before it is retrieved for use. Online games you don’t have access to the storage, but there is more communication. The trick there is to intercept the communication, or to replicate it. If you can make your computer/phone/whatever send the same signal twice, or prevent sending a signal at all, you can trick some games. Some online games store much of their data locally and do not verify against a server, those ones you exploit like a local game.",
"Although my information is dated I know that in at least one instance, the \"cheats\" were commands that were put in for testing purposes. The test team needed to ensure that when you reached level 15 you could do thus and such. Rather than play the game for hours and hours to reach level 15, you use a command that would get you there all at once. Why not take this feature out before release? Because that would mean you were assuming that the taking out the \"cheat\" code would have no impact on the game play, but why take the risk? My presumption is that these cheats are leaked by individuals that are part of the development/test teams. & #x200B; In other cases, you can find these cheats on the game site web pages, especially solo games. & #x200B; & #x200B;"
],
"score": [
6,
3,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
ay8sbd | How are producers, DJs and remix artists able to separate the singing/lyrics from the original song so cleanly? (Without the instrumentals) | Technology | explainlikeimfive | {
"a_id": [
"ehz3gu0",
"ei0ss7m"
],
"text": [
"There parts that are called Song Stems. These are broken down parts of the song. Separate parts like drums, percussion, strings, etc and of course the vocals. Sometimes this is provided by the artists or the label themselves. If stems are not available, a DJ can do pre-work and do vocal isolation. There are many ways to do this but the end is not as clean as stems. Then they add the music part themselves. Last option is to get vocals from cover artists the use it to start the remix.",
"It’s possible to remove the vocal from a track, and by the same token, isolate the vocal. Most commercial recordings are stereo. Stereo recordings do not contain the same information in both channels. This is either referred to as mid/side or sum and difference. Sum and difference is easier to understand. So, there is information that is common to both channels, this is called the sum. There is information contained only in one channel, the difference. If you take the stereo file and convert it to mono, you have the sum track without the difference. Most vocals are placed in the centre of a mix. If you phase invert the mono file and play it over the stereo file, the sum will disappear, which includes the vocals. It’s possible to band pass the mono track to isolate the strongest frequencies of the vocals. Leaving a somewhat accurate version of the track without vocals. You can then take this version, phase invert it, and play it over the original track, leaving only the vocals. Phase invert: sound is a waveform, like a sine wave. If you take a sound, flip the phase 180° (up to down, down to up) and play it over itself, it will cancel itself out. All the sound sums to 0."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ay97pt | Why cant all plugs just be round (like an aux cord) and not weird shapes (HDMI, USB, etc.) so they’re easier to plug in? | Technology | explainlikeimfive | {
"a_id": [
"ehz61oq",
"ehz8gxt",
"ehz69gc"
],
"text": [
"1) Different shapes are a good thing. It prevents you from plugging your monitor into your networking port or audio jack when you really wanted the video port. 2) Lots of digital protocols involve various input and output wires that have to be connected correctly. If you were to plug it in backwards or to the wrong port, nothing would work.",
"Round plugs that you can plug in at any angle have problems getting you more than two or three connectors. If you look at your headphone plug you will see three separate areas that function as connectors. Non-stereo plugs only have two connectors. USB plugs despite being serial have 4 or five connectors. HDMI has 19. How would you cram all these into some coaxial plug that can be turned every which way? The plug would have to be very long insanely complicated and very fragile.",
"With a round plug, you have a limit to the number of unique connections that can be made The most common types of round plugs use one, two, or three connections. A single-line connector is for mono sound (on a pair of headphones or speakers, the same audio would play through both sides). A two-line connector supports stereo sound (differentiating left and right). A 3-line connector is stereo with an added microphone port (basic headsets). Additionally, the potential for 'bleeding' across lines increases. Certain electrical pathways in many electronics have sensitive components, and if too much voltage goes across those pathways, it'll damage the components, rendering the device inoperable. It's much easier to make a device with minimized 'bleeding' using a non-round plug and port."
],
"score": [
13,
5,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ay99jj | How did people edit movies and television shows before computers? How did they change fonts, add effects, etc.? | Technology | explainlikeimfive | {
"a_id": [
"ehz6giy",
"ehz6mma"
],
"text": [
"You can cut and splice film together to get the sequences you want from the various takes. It is also possible to paint over film for title sequences or just hold a board that was made for the show in front of the camera with the words you want on it.",
"They would literally cut and splice film. That's why the command to end a scene is \"Cut!\" Back in the day, if they wanted an effect, they had to find a way to make it actually happen on stage. That's why they're called \"practical effects\" versus CGI. Scale models, real explosions, even dumb stuff like smoke and little spotlights in older films."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ay9kvn | How do you know when a letter or word ends and a new starts when using Morse Code? | Technology | explainlikeimfive | {
"a_id": [
"ehz8jk0"
],
"text": [
"The length of the pause makes the difference. Between letters the pause is three dits, between words the pause is 7 dits."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ayew9b | Why are the UK telephone area codes almost in alphabetical order? | I come from Worcester and now work in Winchester and I noticed the area codes were close (01905 and 01962). This led me to look at a list to see if they were assigned in alphabetical order. & #x200B; And they *almost* are. But with other random towns added in. & #x200B; Why is this? How were they assigned? | Technology | explainlikeimfive | {
"a_id": [
"ei08ers"
],
"text": [
"In may cases it look like it is because of name changes of the zones for example the next after Worcester is Milton Keynes but the area was originally called Wolverton & #x200B; [ URL_1 ]( URL_0 ) & #x200B; So most are alphabetical series but there have been later changed for various reasons."
],
"score": [
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/List_of_dialling_codes_in_the_United_Kingdom",
"https://en.wikipedia.org/wiki/List\\_of\\_dialling\\_codes\\_in\\_the\\_United\\_Kingdom"
]
]
} | [
"url"
] | [
"url"
] |
ayfvv6 | - Why do soap operas look different on TV compared to all other shows? | Technology | explainlikeimfive | {
"a_id": [
"ei12eip",
"ei0oqu3",
"ei1bbfs",
"ei143zb",
"ei0fduw",
"ei0fv70",
"ei0zso3",
"ei1es6p",
"ei1epvy",
"ei19s4q",
"ei1axca",
"ei1cx5h",
"ei1dtsi"
],
"text": [
"they are shot in higher frames, so it looks more fluid, and that makes it look like you are there watching them shoot a scene instead of watching a scene in a movie/tv show",
"It's the lighting. Better tv shows and movies set the light for each shot based on where the camera is. Soap operas set the lighting for a whole set and then leave it. This allows them to film faster but has a lot of limitations around how they light. There is rarely back lighting, for instance. Most of the lights are set from above or from the open \"fourth wall\" behind the camera. They also chose to light very evenly as a style. There aren't a lot of shadows or deep contrast between lightest and darkest parts of the lighting. I assume they did that so older people with worse vision or people using crappy TVs could see the actors better.",
"The short answer is lower quality because of costs. The equipment used for filming and lighting, plus and especially post production costs. Soap operas use a higher frame rate so it actually looks clearer but produces a weird effect of looking TOO real that viewers tend to not like. Most movies and high production TV also go through a slight color filter (usually blue.)",
"It’s a combination of what most of these responses claim: The studio lighting, studio camera setup/lenses used, and the 30fps video framerate. If you look at a multicam sitcom, they suffer the same way. It feels more jarring on a soap opera, I imagine, because soaps want it to NOT look or feel like a stage. With a sitcom, we know the audience is there, the 4th wall is not, and accept the stagey-ness as an inherent part of the form “Why does the frame rate matter?” To understand this you need to understand a little about photography and shutter speeds. I’m not going to define those here. The framerate shot matters in TV because you are used to seeing the way things move and appear on films where the action captured on each frame is typically captured with a blur that’s equivalent to a still camera shooting a picture of a moving object at 1/48th second (I said “typically”—don’t clap back at me about shutter angles). When something shoots at 30fps, the look of the motion captured on each frame is more akin to a still photo captured at 1/60th. (nb: new stuff, even shot for tv, frequently shoots at 24fps now. The stage setup and lighting still create that artificial look, but it’s less dramatic because the framerate is now consistent with what we’re used to in movies)",
"Because they're filmed almost exclusively in studio sets where the lighting is incredibly bright and the perspective is always the same. Other shows and movies are shot outside or in normal buildings.",
"The realistic / real-time look comes from filming 29.97 frames per second compared to movies which are traditionally filmed at only 23.98 frames per second.",
"A few of you guys are right. It has to do with framerates and frame blending. Soap opera's are shot on video, mostly 29.97fps interlaced. The fields (one half of the horizontal lines) can get mixed with the frame before/after (frame blending). In theory it's supposed to make the motion smooth and not jerky. In practice most people would rather see solid frames. You'll notice in some older TV shows (happened a good bit in X Files) where there would just be a short clip that looked like it was filmed on a camcorder. That's because they either added a shot that used a different camera or dropped it in during a certain phase of editing where it didn't have the same video specs as the footage it was mixed with. Ultimately I think soap opera fans like the look, and it's mostly done because they're made cheap and fast.",
"The soap operas look differently because of the lighting. They use a lot of lighting from all angles so that they can shoot different scenes and shots back to back. They have to do this because soap operas usually have daily episodes. Having lighting specific to each scene and then having to change that would take too much time",
"[Austin McConnell did a great video on this]( URL_0 ) Soaps use a one camera setup so that they don't have to waste time moving the camera around. They put massive amounts of footage each year so they have to.",
"It’s a combination of a lot of things, their budget is much lower than that of primetime shows, their production schedule is crazy, they sometimes film 2-3 episodes in a day and the lighting techniques are different as well. [This article is old but explains it very well ]( URL_0 )",
"They are produced and most importantly lit very cheaply, and they green light sometimes 10 years worth of seasons in advance. They are shot differently than higher budget shows because they mostly have 3 and even two wall sets. They look different because they look like shit, and they look like shit because they have shit budgets, and they churn out as much garbage as they can afford to to fill those daytime slots.",
"They look different because they are lit differently. Generally speaking, every shot in a film or TV show is individually lit, so it gets the perfect mix of contrast, exposure, tone, etc., and that's why it takes so long to shoot movies and tv shows, usually only 2-3 pages/minutes per day. But soaps have to shoot an entire episode every day, so they basically light each set for general use and then block the actors onto standard marks, with fingers crossed that the lighting will look approximately correct. Sometimes you'll even see shadows fall across an actor's face because's he's unusually tall, or leaned the wrong way, and the standard lighting couldn't accommodate it. The difference between video and film does also play a role, as does different frames per second, but it's generally lighting that makes the biggest, most noticeable difference.",
"So: on a **movie**, or a \"one camera\" show (a show shot like a movie, like GOT), each shot is lit specifically for that show, and it is a whole art. The top cinematographers (the cameraman or woman) go for a particular kind of lighting, carefully crafting it to match the mood of the film--more gritty, more moody, darker, brighter, etc. They work with their chosen top lighting technicians, who are known as gaffers, and set the lights (the top assistant gaffer is known as the \"best boy,\" if you've ever wondered about that credit). So that's why you have a movie that looks like \"The Godfather,\" vs. a movie that looks like \"The French Connection,\" vs. any other movie whose look you admire. The director will work with his favorite cinematographer, who in turn has his chosen team of lighting technicians. On a **sitcom,** the show is shot like a stage play, almost. You have several sets, that you always shoot on, set up like a stage (i.e., facing an audience), and for efficiency, and on a far smaller budget, the shows are shot with multiple cameras, and the lighting has to work for every shot, so there's far less subtlety, and lights are not reset between shots. Still, though, there are differences between directors and cinematographers, and lighting technicians. A **soap opera** is the cheapest of the cheap. They're designed to be the cheapest possible productions. The sets are cheap. The makeup and hair is cheap. And most of all, the lighting is cheap. They generally set up a few what are called \"BFLs\" (Big Fucking Lights) and they are not moved, changed, or altered. For this to work, the lights are as bright as possible so there are no shadows on the set. They also use cheap camera equipment and are usually some kind of inexpensive digital video cameras. They shoot them every single day, so they need to be as quick, efficient, and cheap as possible. The audience is watching for mild entertainment, to follow the easy stories, and enjoy watching their favorite actors or actresses, and does not care at all what it looks like, so there's no particular motive for them to make them look better. TL/DR: cheaply shot, cheaply lit, cheaply produced"
],
"score": [
2612,
754,
251,
47,
23,
20,
7,
4,
3,
3,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://youtu.be/h683ckfeNok"
],
[
"http://mentalfloss.com/article/25169/why-did-soap-operas-look-different-other-tv-shows"
],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ayfxvm | Why is prime factorization so reliable for modern encryption algorithms? | Technology | explainlikeimfive | {
"a_id": [
"ei0g7io",
"ei0g55s",
"ei0nc5e"
],
"text": [
"When doing encryption, two things has to be true: 1) It must be easy to calculate 2) It must be hard to reverse Multiplying two prime numbers is insanely easy for a computer, so 1) is true. Finding out which two prime numbers were multiplied together to get a number is impossibly hard to do (within a reasonable time frame) for a computer. Basically, the only way to truly know which two primes multiply together to form 144 483 604 528 043 653 279 487 is to multiply every single prime with every single other prime to see if it gives the correct answer, and each calculation takes some time. At some point you'll get the answer, sure, but what does that help if your calculation takes fifty thousand years?",
"It is very hard for computers to calculate. In fact, we don't know of any algorithm faster than exponential time (more or less) to factor numbers. We do have an algorithm to factor numbers in polynomial time, but this only works on a quantum computer. Why this problem is so hard, and whether it can be solved on a non-quantum computer in polynomial time, is an unsolved question in mathematics.",
"> Ultimately, this doesn't seem to be too hard for computers to calculate, so why is prime factorization so difficult for computers? Depends what you mean by \"hard\". It's super easy to write a program that will compute prime factors. It's extremely difficult (and may well be impossible) to find one that will do so *quickly*. The numbers used in cryptography are very big - so much so that even with the fastest known algorithms on the most powerful computers available, it would take far too long to factor them to be practical."
],
"score": [
15,
14,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aygyd0 | How does encryption/decryption of a file work? | Technology | explainlikeimfive | {
"a_id": [
"ei0r1c6"
],
"text": [
"Let's talk about a simple \"toy\" encryption algorithm. A file is a series of bytes, which are made of bits. An encryption algorithm will take a \"key\" which is a number that is secret and needed to recover the file. The algorithm will go through the bytes in the file and do a mathematical operation on the bytes and key to produce new values. Let's say the key is 256 bits (a fairly common number). We'll go through the file 256 bits at a time an do an operation called \"XOR\" where if two corresponding bits have a \"0\" and \"1\" the output bit is \"1\" otherwise it is \"0\". XOR has a property that A XOR B XOR A == B, meaning by doing an XOR with one of the two operands a second time, you recover the other. For added removal of patterns, we shuffle the output bits in some predefined way. The end result is a file that looks nothing like the original, but which can be recovered by simply redoing the process since (data XOR key) XOR key gives you the data back. Now, this strategy has a big flaw in that any 256 bit value that is the same in the input will turn into the same result in the encrypted file. So what we'll do is after XORing the key and first 256-bit value together, we will take that value and XOR it against the next 256-bit value before XORing with the key, and repeat this down the file. This causes a rapid chaining of information, which makes the output much less predictable. Undoing it still just requires the key. & #x200B; Modern encryption algorithms are more complex than this, but this shows a way to take a known number and make a file totally unreadable without decryption or cracking it."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ayi2dj | How do bots work to buy Hype items? Supreme had items drop today that sold out in less than 3 seconds. How does the bot know where to click to get the item and size, as well as overcome Captcha? | Technology | explainlikeimfive | {
"a_id": [
"ei0wucc"
],
"text": [
"It doesn't generally have to \"click\". Your browser sends a message to the server saying \"I want to buy this\" and then does some other messaging to send payment info. A bot could do these things without a browser. A second option is to write scripts in your browser to do it. A webpage has a structure that a program can read and manipulate, and it can simulate clicking without actually doing it. & #x200B; For captchas, if it is good a human likely must do it. A script could pop it up for the user once it is available, or you can outsource captcha solving to groups of people who solve them for a fee."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
ayi9lm | Why is adding a dark theme to an app/OS so hard and doesn't take just a few color changes? | Technology | explainlikeimfive | {
"a_id": [
"ei0zd3n"
],
"text": [
"from my experience, it's the chaotic way in which designers end up serving specifications. Might be more true in web but designers don't often enough get enough time or info to plan out a theme for their project in such ways that inversions of colors can just happen on the fly and you gets palettes with too many colors that get used inconsistently in the designs that you then have to flip somehow. things aren't defined, for instance, as background color, title color, text color, link color from the start but a humble of colors that are sometimes backgrounds sometimes links sometimes 1 shade away from every other view/page in the project making the scope of such a theme change pointlessly more difficult based on the average client's willingness to incorporate principles of accessibility design I'd be surprised if things got better"
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aykz9k | - How do Video Game servers work? | Technology | explainlikeimfive | {
"a_id": [
"ei1k5j5",
"ei21w49"
],
"text": [
"I'm going to assume you're talking about servers for typical FPS (First Person Shooter) games. All the server is doing is acting as a \"middle man\" to ensure all of the players (clients) know what all of the other players are doing, and to handle any reactions to those players actions, and again, ensuring all of the players observe the same reaction at the same time. Multiple times per second, your computer sends information about exactly where you are and what you are doing - moving in a certain direction, opening a door, firing a gun - and does the same for every other player at the same time. Then, multiple times per second, the server shares that consolidated information with all of the players, so that each player's computer knows what to display on the screen. Certain decisions are also made by the server - did that bullet you shot hit that other player? How much damage did it do? Did it kill the player? All of that information is sent to all of the players at the same time, so everyone observes the same thing. It gets more complex.... on games with really big maps, the server may only share information to players from other players in their vicinity, so not every player is receiving the same information, but players who are close to each other would get very similar information. This is a very high level summary - it gets far more detailed and complex and varies between different games.",
"This is explained fairly easily by looking at the history of multiplayer gaming. In the good old days, before game servers existed, you had to know someone's IP address in order to play against them. What happened was, one person from the group would setup the game, they would be the \"host\". All the other players (the \"clients\") connected to this game using his IP address. (Or worse, in the age of dial-up modems, you'd use a direct modem connection to play, where one player has their modem dial the phone number of the other person, obviously this only supported 2 human players. In those days LAN gaming was also an option, it was much faster than internet and the host machine could broadcast the game over the LAN rather than needing to enter IP addresses, but it meant you needed to be physically connected to that network.) So that sucks, you have to know the people you're playing, or at least have some one of sharing the IP address and planning when to play. And you can have network problems with NAT and firewalls and stuff. So matchmaking servers were created, which were a central known server that everyone could connect to in their game. Someone would host a game game, and the game would broadcast that to the matchmaking service. This could be a service specific to the game, the developer (eg. URL_0 , Westwood Online), or a third-party service (eg. GameSpy). Then everyone could browse the available games and join one. The matchmaking service took care of connecting the clients to the IP address of the host, and maybe it would track some game stats and stuff, but that's about where their responsibility ended. Not long after, players and developers realised that a multiplayer game would be much more stable if one of the machines was dedicated to hosting the game - a dedicated server. This machine could devote its system resources to ensuring communication with all the players. No one was playing on this machine, so it didn't put too much stress on rendering graphics and handing player input. Developers would eventually provide a version of the game that didn't render graphics at all, and was run and controlled via the command line. The host player would often have an advantage when it comes to lag, since his machine controlled the game locally and had the final say over network conflicts; this advantage was removed with a dedicated server. Also, since the host machine controls the game, people quickly found that a host player could cheat at the game. So dedicated servers hosted by the developers or third-parties became a thing. In modern online multiplayer, not a whole lot has changed architecturally. Developers and other third parties (like Valve, Microsoft, Sony or Nintendo) still host dedicated servers for their games, recouping their costs via sales of the game, DLC/microtransactions, advertising or online subscriptions. The servers essentially run a simulation of the game that doesn't participate or render graphics, sitting on an unmanned machine. Of course these days game servers are run across multiple computers in the cloud, likely using Virtual Machines - virtual computers that can be spun up or shut down as demand rises and falls. And even today, you still have the dichotomy of some games that use this client-server architecture (multiple players connecting to a single dedicated server), or use some kind of peer-to-peer architecture (like the old days of players connecting directly to each other via matchmaking services, where either one player is the host and has control; or games where there is no one machine in control, and some kind of consensus amongst players needs to be reached). And peer-to-peer games can still have problems with cheating without significant effort to prevent/detect, and suffer more from lag because basically the game can only run at the speed of the slowest person. But they don't require paying for dedicated servers, so it's a financial decision that developers still make. Nintendo games for example are all P2P. Now there's a lot of technical details you can go over regarding what exactly a dedicated server does. There's lots of cool network engineering, physics and maths-based logic and tricks that goes into ensuring a smooth experience for all the players, dealing with lag and network conflicts, preventing/detecting cheaters etc. But the crux of it is, they're hosting a non-graphical version of the game that has the final say over all game activity, that every player connects to over the internet, and which controls which players receive which information."
],
"score": [
7,
5
],
"text_urls": [
[],
[
"Battle.net"
]
]
} | [
"url"
] | [
"url"
] |
|
aylrt0 | How do computers understand your code? | Technology | explainlikeimfive | {
"a_id": [
"ei1rbso"
],
"text": [
"Programming code is compiled by the compiler into Assembly language which is your code in a form of cpu instructions and memory addresses. Assembly is not very human readable so back in the day higher level languages emerged like cobol, fortran, Dartmouth Basic, and C to name a few. These langs were more readable and easier to work with, and started being taught in colleges. Theres a video on this exact topic on youtube showing a simple example of code in C and its assembly version."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
aymo3q | The difference between DIY grade power tools and professional grade power tools | Technology | explainlikeimfive | {
"a_id": [
"ei1w384",
"ei1wdgf"
],
"text": [
"The wear parts in professional tools are much better designed; bearings, bushings, contactors, brushes. This makes them much more expensive, for no real change in function, and have much longer life. If you use your saw for hours every day, you will have it long enough for it to wear out. It's a big advantage to have one that lasts 5 times longer and costs 3 times as much. For a DIYer, either saw will last a lifetime, and one is 3 times as much.",
"More metal internal parts versus plastic. Tighter tolerances between moving parts so they can be used more precisely and don't wear out as quickly. More/better lubrication on moving parts. Cases housing moving parts are sealed better to keep lubrication in and keep contaminants out. Designed to be serviceable rather than disposable. Better overall quality control at the factory and better warranty."
],
"score": [
12,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ayoa49 | Youtube search is creepy | Technology | explainlikeimfive | {
"a_id": [
"ei25ev9",
"ei27mln"
],
"text": [
"It's a whole thing with companies monitoring what you search so they try and show you things relevant to you. This is what cookies are for.",
"Because you're not the first person to watch that video. Millions of people watched it already and some of their next searches was central tire inflation system. In addition, it's basically some team's job to write software to recognize subject keywords in videos."
],
"score": [
9,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
ayrspt | If the infrastructure 15 years ago is still being used by cable companies today. Then how can they provide such higher internet speeds? | Currently I have 200 Mbps internet (I could have 400 Mbps with the better package) on non-fiber optic line. 15 years ago it was very good to just have 20 Mbps consistently and now it is a laughable speed. If I am not missing something, how can cable companies maintain these high bandwidths and speeds now with the same infrastructure from 15 years ago? I understand how fiber optic cables maintain a higher bandwidth/speed (kinda) but if copper wire had this capability then why couldn't we have these speeds 15 years ago? | Technology | explainlikeimfive | {
"a_id": [
"ei2t3l6",
"ei2sw12"
],
"text": [
"Let's say you have a 7 lane interstate. At each end there is a toll booth. In the past payments were processed manually and there was a receipt that had to print, but the printers were slow. Only do much traffic could get through. Fast forward to the future where you pay with the touch of a button and get an instant receipt or pre-pay before you get there and just zoom right through. Ignoring I know nothing about toll booths, this is basically why. The info in the past couldn't be processed as quickly, so there is always a bottleneck. Today it's much faster. I'm not sure if we've reached the physical limitations of the current infrastructure though. I know we've come up with better ways of transporting the info such as the digital equivalent of carpooling or taking the bus. Only so far you can go before you'll have to expand the interstate or change to a better mode of transport. Like bullet trains...or Elon Musk's idea of the hyper train system. What is it called again?",
"Essentially, the tech on the transmitting and receiving end are much better. Cable internet over coax uses DOCSIS (Data Over Cable Service Interface Specification), which has had periodic improvements made to allow it to operate faster. More specific details can be found here. URL_0"
],
"score": [
6,
5
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/DOCSIS#Comparison"
]
]
} | [
"url"
] | [
"url"
] |
ayu5t2 | 3D Printing | Hey, there. I'm not a very technologically-inclined person and depend on my boyfriend when it comes to anything new. I didn't know 3D printing was even a thing before joining reddit (a few months ago, I'm late - I know). How does this even work? Do you have a computer connected to it? Is there certain software? How does it just make a solid object?? | Technology | explainlikeimfive | {
"a_id": [
"ei39dqg",
"ei3dglt"
],
"text": [
"At a simplified level, imagine if we slice a 3D object into a series of 2d layers spaced a small distance apart, and then use molten plastic to draw each layer at a small thickness, and then stack each of those layers we just printed on top of each other. That's the general idea of 3d printing with many consumer printers. There has to be code that takes a 3d model from a modelling application in order to generate those layers and they have to be sent to the printer by some means, but that's not much of an issue.",
"Have you ever made a little clay or play dough pot by rolling out thin clay spaghettis and then laying them down in a spiral going up and up till you had a little pot? That's the way the most affordable type of 3d printing machines work. Except the machine uses plastic instead of clay, and the plastic already comes in one long spaghetti wound on a spool. It pulls in the plastic spaghetti, heats it up till it melts and a computer that can interpret 3d plans controls the position of the print head the molten plastic comes out of very precisely so it can lay down a very thin molten plastic strand in a very long spiral going ever higher following the shape of the 3d model in the computer."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
ayvjkl | How does a computer or calculator calculate the square root of something | Technology | explainlikeimfive | {
"a_id": [
"ei3lfgx",
"ei3k7s8"
],
"text": [
"Here is a possible way: What is the square root of 5? I don't know, but it's between 1 and 5! Maybe it's 2.5. Let's check. 2.5 squared is 6.25. Oh no, that's too big. So it's between 1 and 2.5. Maybe it's 1.25. Let's check. 1.25 squared is 1.5625. Oh no, that's too small. So it's between 1.25 and 2.5. Maybe it's 1.875. Let's check. 1.875 squared is 3.515625. Oh no that's too small. So it's between 1.875 and 2.5. Etc etc until the difference is smaller than 0.000001 or whatever your accuracy needs to be.",
"There are methods that can be used on an arbitrary function to compute where it intersects a line. The earliest of these is called Newton's method and basically uses the tangent of a curve to compute an approximation, then from that approximation does it again to get a better one, so on until the value is \"good enough\" for the purpose."
],
"score": [
12,
11
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
aywqoo | Why is it when round objects spin at a certain speed they appear motionless? | Technology | explainlikeimfive | {
"a_id": [
"ei3s2mi"
],
"text": [
"Your eyes have a frame rate per second, when an object is spinning and matches your eyes frame rate they appear motionless. This is why helicopters blades will appear motionless on high speed cameras"
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
az51cs | How do headphones work? | Technology | explainlikeimfive | {
"a_id": [
"ei5acsn",
"ei5cgco"
],
"text": [
"Headphones are simply 2 baby speakers that sit very near your ear.. Since they're tiny they require very very less power, are less loud and the dynamics of sound are more notable as they are very near your ear!",
"There are small magnets that vibrate at a certain frequency (repetitions per second) as a way to augment sound these are called drivers. The drivers in your earbuds are extremely small, yet since they are so close to your ear they sound a lot louder."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
az82wc | How do speed cameras capture speed? | Technology | explainlikeimfive | {
"a_id": [
"ei5ydpo"
],
"text": [
"In my understanding it's not the cameras that catch speed, they only take a photo of the speeding vehicle. You have either a ground sensor that measures the speed with which the wheels of the vehicle get from point A to point B, or a laser sensor that measures the speed of the object by comparing how long it takes for the light to bounce back in a couple of measurements."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
az8hd2 | water damage to electronics. | I know that water is conductive, but I don’t quite get why water will harm something electric. For example, a phone dropped in water or left in the rain – why do they stop working? A toaster in the bath would kill someone, but why does the toaster “fry”? To boil it down to one question, what makes water and tech a bad mix? | Technology | explainlikeimfive | {
"a_id": [
"ei60861",
"ei60hjb"
],
"text": [
"The water allows the electricity to jump from one circuit to another it wasn't meant for and it can destroy the components on things like the motherboard.",
"Because water is conductive, it connects connections that are not supposed to be connected. Short circuits are bad, it lets too much current that isn’t supposed to be there through connections that aren’t necessarily supposed to deal with it. Electronics are sensitive, a few short circuits fries things really quickly."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
az9wjn | How do game developers generate fog? | I started learning opengl and I know about vbos, vaos, and shaders. I know what fog is in real life, but in video games, what *is* it? How do you make weird and realistic bumpy and foggy shapes? To clarify, I'm not talking about rendering distance here. I mean the physical up close oozing around and even reacting to the player kind of fog. | Technology | explainlikeimfive | {
"a_id": [
"ei6anvz"
],
"text": [
"Particles. I wish I could tell you more about it than that, but I can tell you that much. It’s the same way they generate fire (and sometimes water). As I understand it, it basically involves rendering colored points rather than shaded/textured polygons and then writing rules about how they behave collectively (how they move together, stick and break apart, etc.)."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
azfq5l | How do we get propane and other gases from the ground? | If there are pockets of gases in the Earth how do we get them from the ground without the gases just dispersing into the air? | Technology | explainlikeimfive | {
"a_id": [
"ei7g1b7"
],
"text": [
"We refine crude oil which contains gases in the oil(similar to carbonated beverages but less fizzy) and can undergo chemical reactions which will take bigger molecules and break them down into smaller molecules, like propane, which we then seperate out."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
azjlrw | How do barcodes work? How is it that they can be universally read and we haven’t “run out” of options for them? | Technology | explainlikeimfive | {
"a_id": [
"ei8h34l",
"ei87zwi"
],
"text": [
"Others have explained how they work, so to the other questions, they use standardized formats for the patterns of lines and spaces to make them universally readable by equipment that follows the standard. We don't run out of options because there are many different standards (UPC-A, UPC-E, ISBN, multiple EANs and GS1s, etc.) for [linear barcodes]( URL_0 ). Also importantly, they're not unique. When a single barcode can refer to multiple things, it's up to the system scanning to determine which one it refers to. (Typically they're not reused until the last thing they were being used on is no longer officially sold 'new'.) You could create and print your own barcode labels to label and inventory your stuff if you wanted, assigning them as you see fit. Other scanners could read the barcode if it uses a standard format, but wouldn't know what items they referred to unless you gave them the list to map ids to objects and their software was using that mapping. Since there are many sources for different types of bar codes with different mappings, there is no single universal database of mappings. Retailers who want to use them get the mappings for the products that they carry from their suppliers/distributors/manufacturers. This, combined with the non-uniqueness over time and products, and the many different sources/formats, is why they are often not used at places that sell used items like used bookstores, thrift shops, flea markets, etc. However, you may see some larger/busier ones that issue their own barcodes and labels as they add items to their inventory. Since it's their own system and they created the barcodes, they know what they map to. But the same barcodes read by another system (without the mapping) wouldn't.",
"You know how the barcode scanners sort of 'flicker' that laser light? That's because it's rapidly switching from emitting laser light to 'looking for' laser light. The quick flash of light reflects off the upc code and it sees the width of the white space, broken up by the black bars. This translates into a code of numbers. These numbers used to be reused after so many years because there certainly is a limit to the number combinations. Once a product is no longer sold in stores, the company will stop renewing the upc codes, and they'll know that eventually they can recycle the code. This changed recently, and as of last year, they've decided to stop recycling codes for old upcs and eventually we will switch to the more complex QR codes which hold significantly more data, but essentially work the same way, just on two dimensions instead of the one."
],
"score": [
24,
8
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Barcode#Linear_barcodes"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
azkb5k | why does the video quality decline when a video is reposted over and over again. | Technology | explainlikeimfive | {
"a_id": [
"ei8cgu8"
],
"text": [
"Video compression is lossy, meaning data is permanently lost. Presumably in the cases you are talking about, the video is decoded and then recompressed using the hosting website's algorithm of choice. Doing this will cause more data to be lost, as the compression doesn't \"remember\" the previous compression algorithm's effect. The same thing can happen with jpeg images: cropping or rotating it will inevitably cause a slight loss of quality. Do it enough times and the image quality can get quite bad."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
azkdf2 | How can data be recovered from hard drives even after multiple wipes? From my understanding when you wipe a drive you're resetting all the ones and zeros so do drives somehow remember their old data? | Technology | explainlikeimfive | {
"a_id": [
"ei8edwg",
"ei8dy2t",
"ei8x6x1",
"ei8h902",
"ei9437x"
],
"text": [
"If you overwrite the disk once, nothing remains. If you just format the drive, all it does is overwrite the beginning of the drive, which tells operating system what file system is being used, where them files at etc. All the files and their data is still there, but the index that described where to find them is lost. Still, if you were to actually browse through the disk, you'd still be able to figure out what files there were. Overwriting a 1TB disk requires you to write 1TB of data. Most disks only write like 100MB/s, so you'd have to spene 10,000 seconds, or 3 hours, overwriting things. Most users would never bother with that. Deleting files works similarly. Afaik no commonly used operating system actually overwrites the file upon deletion, they only remove it from the address book and mark that area as free space available for new files.",
"When you erase a file, you're usually not erasing it, just deleting it from the registry. The ones and zeros are there, just not easily accessible, until they get overwritten. So to completely erase everything on the drive so that it can't get recovered, you'd need to completely overwrite everything on the drive.",
"More than one overpass and the data is gone. Otherwise you can attempt bit-by-bit recovery using magnetic microscopy at insanely prohibitive time and cost, the likes of which only a federal agency might have.",
"Theres are some recovery possible even after physical over writing. Apps like dban have the option to run multiple zero-wipes then one-wipes to make sure its scrambled good. You can magnetically wipe the drive with a degausser too. That leaves nothing behind.",
"If you format a drive on Windows, there’s an option called “quick-format”. Basically, it doesn’t actually erase anything once you do it, it just makes it look like you did. But when you put new data on, it’ll overwrite the data that you quick formatted slowly. Quick formatting essentially says “it’s okay to delete these files when needed”. If you quick format a drive, nothing is actually gone. When you do a real format, Windows goes through the drive and changes all the 1s to 0s, so there’s nothing on the drive anymore."
],
"score": [
8,
6,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
azlne1 | How did ancient people handle termites? How are the wooden bridges and temples lasting hundreds of years? | Technology | explainlikeimfive | {
"a_id": [
"ei8ozi2",
"ei8ot8f",
"ei8x5jk",
"ei8p4ww"
],
"text": [
"Any particular locations in mind? Termites aren't a problem everywhere. They only really inhabit consistently hot (or at least warm) regions so, for example, northern europe is termite free.",
"I don't think there are many solely wooden structures that have lasted hundreds of years. The idea of treating wood has only really taken hold since the industrial revolution. Structures that used wood that have survived, such as timber framed houses, have done so for two reasons. Firstly, they used a very hard wood like oak which is hard to start with and becomes incredibly hard over time. I grew up in a house in Hertfordshire, England which was built in about 1600. The oak timbers were incredibly hard - builders we had said their power drills wouldn't touch them. Secondly - and this applies to most older structures - they used designs which were strong in their own right, rather than relying on the strength of the material. So for instance, an arch bridge is incredibly durable - the shape itself resists any loads put on it. It's the same with a timber framed building - the timbers themselves actually do degrade, but the design - with braces and brick infill - is inherently very strong. Modern structures, made of concrete or steel, rely on the fact that the material itself is very strong, which is why you can build things thousands of times bigger. But both rely on the strength of the metal (metal reinforcement in concrete) and that degrades over time, which means they will always have a finite lifespan. It is more economic to build a bridge with less material knowing it will last 70 years, than overengineer it to last 700 years. tl;dr you don't need to have amazing wood preservatives if you have high quality wood and build the structure so that it won't matter if the wood loses some of it's strength.",
"in Japan, a traditional way to weather and bug proof wood was to actually char the surface. this also made it fire resistant too. one way they did this was to tie boards together in such a way that it made sort of chimney. the boards were stood up vertically and a fire was started in the hollow space in the middle. the fire would quickly travel up the interior, burning the surface. the core of the wood would still be strong and durable.",
"Termites only thrive in warm climates, between the 40th parallel north and the 40th parallel south. Which means in large parts of the world termites are a non-issue."
],
"score": [
35,
18,
4,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
azsyaz | How do our cheap electronic clocks automatically change time when it’s spring forward? | I have a cheap electronic clock from Walmart. Did it get programmed for the next 6 years or how ever long it may last as an appliance? Or is this some circuit board clock embedded? I seriously have no idea. | Technology | explainlikeimfive | {
"a_id": [
"ei9uzyx",
"eia74n9",
"eia1g1t",
"eia55wz",
"eia7368"
],
"text": [
"Did it automatically set its time? There are radio stations that broadcast the time is a format that can be easily deciphered by electronics. This allows clocks to automatically set the time and change to DST.",
"URL_1 URL_0 A single station in Fort Collins, CO transmits a WWVB signal at an *exceptionally* low frequency of 60kHz. That gives exceptional continentwide coverage and building penetration. GPS receivers give reliable time, but are unreliable indoors, esp with a metal roof. 60kHz will penetrate most walls. But 60kHz data rate is *exceptionally* low. 1 baud. ONE bit per second. It takes a full minute of error-free data to convey the time of day. It sources the standard from multiple atomic clocks and is fantastically accurate. Many technical apps demand an accurate time standard, although many use a GPS antenna external to the building.",
"A bunch of wrong stuff in this thread. WIFI is just silly. You have to be logged into the network for it to work. Really, think about it.... GPS could work - but why put a GPS chip into a device when you have had (for decades) URL_0 Radio. And it is free. This place is amazing. People talk out there assholes and it stays up, but you keep it short and sweet and it gets auto deleted. You then message the mods and they double down on there fiefdom.",
"If you're in the US, our National Institute of Standards and Technology powers longwave radio station WWVB (among others) which exists partially to broadcast time signals to radio-controlled clocks. Here is their list of Manufacturers of Time and Frequency Receivers, along with other links about NIST's time and frequency services: URL_0",
"There are a few ways to get the time automatically, but only a few of them make sense in cheap electronics : either it uses an (almost) worldwide radio broadcast, or it was programmed on the chip, which is trivial with modern electronics and works fine as long as the date of winter/summer time doesn't change. If your clock is set automatically, usually every night, it uses radio broadcast Wi-Fi doesn't make sense unless it has other connected features (such as streaming music), GSM network is more complex, and you usually can't get GPS signal indoors, so they don't really make sense on a simple alarm clock More info : URL_0"
],
"score": [
71,
42,
16,
9,
3
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/WWVB",
"https://en.wikipedia.org/wiki/Radio_clock"
],
[
"https://en.wikipedia.org/wiki/Radio_clock#List_of_radio_time_signal_stations"
],
[
"https://www.nist.gov/pml/time-and-frequency-division/radio-stations/wwv/manufacturers-time-and-frequency-receivers"
],
[
"https://en.m.wikipedia.org/wiki/Radio_clock"
]
]
} | [
"url"
] | [
"url"
] |
azywrw | Why do photographs of screens look like they’re “moving” when you zoom into them? | Here’s an example: URL_0 | Technology | explainlikeimfive | {
"a_id": [
"eib1cad"
],
"text": [
"> Photographs of a [TV]( URL_1 ) screen taken with a [digital camera]( URL_2 ) often exhibit moiré patterns. Since both the TV screen and the digital camera use a scanning technique to produce or to capture pictures with horizontal scan lines, the conflicting sets of lines cause the moiré patterns. To avoid the effect, the digital camera can be aimed at an angle of 30 degrees to the TV screen. [Moiré]( URL_0 )"
],
"score": [
4
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Moiré_pattern",
"https://en.m.wikipedia.org/wiki/Television",
"https://en.m.wikipedia.org/wiki/Digital_camera"
]
]
} | [
"url"
] | [
"url"
] |
azz9zj | Why are some gas cylinders filled with other materials? | I heard that for example acetelyne cylinders are filled with a stone-like material similar-looking to pumice. What is the purpose of those fillings and wouldn't it allow less gas to be stored? | Technology | explainlikeimfive | {
"a_id": [
"eib41jh",
"eib3ypw"
],
"text": [
"That gas is explosive if above 15 psi. Obviously there's more than 15 psi in the tank so they dissolve the gas in acetone and use the pumice like stone to absorb the liquid to keep the tank from spontaneously turning itself into a bomb.",
"The pomice is there to suspend the acetone in acetylene. The acetone is there to stabilize the acetylene."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
b01ibj | Why does radio reception sometimes increase when we stand next to a radio or touch the antenna? | Technology | explainlikeimfive | {
"a_id": [
"eibm8i8"
],
"text": [
"Your body reacts to electromagnetic radiation (which includes radio). FM just happens to have frequencies near the resonant frequency of the human body. So your body acts like a tuned antenna for some stations."
],
"score": [
13
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b024c5 | what does it mean when a song/album is remastered? What changes? | Technology | explainlikeimfive | {
"a_id": [
"eibsa0j"
],
"text": [
"The songs you usually listen to, at least digitally, are mostly in a format called .MP3 This format basically takes hundreds of megabytes' worth of audio data, and compresses them into just a few megabytes. When you master a track, a large part of the process is controlling how that compression process takes place. During compression, many audio frequencies are lost. There is audio all around us, including breathing, friction, and even the air in the room. As opposed to vinyl records, in which you can usually hear many of these frequencies (making it sound very realistic as though it is played next to you), .MP3 formats omit them. It's impossible for that compression to take place without affecting the music at least in some way. Original mixes tried very hard to minimize any effect that could make the music too \"flat\", or affect the richness of the audio. However, day after day, audio equipment get better and sound engineering advances greatly. This means that mixes made in the 1990's could contain undesirable compression errors that we have the tools to fix now. This is where a remaster comes in. It's basically to push the sound quality of older recordings into places that were not possible at the time. & #x200B; N.B. Remastering isn't exclusively meant for compressed audio like MP3. It could be used to fix mixing flaws or rework other mixing errors that weren't caused by compression. However, the majority of remasters deal mostly with compressed tracks. That's where the noticeable difference is. You can't spot much change in an original vinyl record, and a remastered one. (Unless creative changes were made, i.e. artistic choices to change certain sounds)"
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b02za4 | why is there such an effort from companies to block resale of promotional freebies? | In particular I am referring to the recent free game promotions with AMD and Nvidia hardware. They make you go through hoops to prevent you from giving the games away or selling them. Is there a legal reason for it or is it something else? Why do they care what you do with them? | Technology | explainlikeimfive | {
"a_id": [
"eibvfwf"
],
"text": [
"Because it's a potential for lost revenue... And yes, there is a very big possible legal penalty - piracy and/or conspiracy to commit piracy and/or aiding and abetting piracy. Whatever you call it, what you're describing is theft."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
b03r87 | The difference between the World Wide Web and the Internet. | Technology | explainlikeimfive | {
"a_id": [
"eic015d",
"eic2fzp",
"eibzsyq"
],
"text": [
"The internet is the network that connects millions of computers together. The World Wide Web is the part which you access through your web browser. Online games, for example, use the internet, but aren't part of the www.",
"Internet is broader term for whole computer network no matter what protocol computers (servers) use. The world-wide-web is a narrower term denoting computers/network that provides access to hypertext (i.e. web pages) via HTTP/HTTPS protocols. The hypertext is the reason (imho) why internet gained such popularity and is the most visible aspect of internet, so it is frequently as synonym for internet, but there are other protocols servers use in internet, for instance for email there are POP3/IMAP for receiving emails and SMTP for sending ones. Or each chat application like Snapchat, FB Messanger Slack etc uses its own protocol.",
"Okay, so I looked this up. It appears that the internet is computers linked together to share information, etc. While world wide web is the specific sharing of information through URL_0 . Someone else may be able to explain better but that was my five second lesson! Source: URL_1"
],
"score": [
12,
6,
3
],
"text_urls": [
[],
[],
[
"http://www",
"https://www.theedigital.com/blog/differences-between-the-internet-and-world-wide-web"
]
]
} | [
"url"
] | [
"url"
] |
|
b068m1 | When deleting apps, games, etc, from your computer, where does that data go? How does that memory it used to take up, get erased? | Technology | explainlikeimfive | {
"a_id": [
"eicce2z",
"eiccdh2",
"eice1fz",
"eiccqs8"
],
"text": [
"Your game occupies a house in your PC's disk. You tell your PC you don't want that game anymore. The house continues to be there, it doesn't get erased or go anywhere. But as soon you install a new game, your PC will build a new house on top of the old one.",
"It doesn't actually, strictly speaking, get deleted. It's more like... the system forgets where the data is stored and what it means. The 0's and 1's are still there, until new information is written over it.",
"Continuing the house analogy, the data is still in the house until new data moves in, just the house address is lost. So a forensic exploration may find it. That is why a drive needs to be over writen, or physically destroyed if it contains info that should never be found. A hole drilled through it is the easy wsy. Not an issue for most personal use computers.",
"The file system will have a list of what sections of the disk is used and what sections are unused. When you delete data from the disk it will put these sections in the list of unused sections. It will also remove the file from the directory listing. So when you write new data to the disk the file system will look for unused sections it can use and might find that the sections containing the old deleted data is listed as unused. In that case it will reuse those sections for the new data. So when you delete the data it is technically still on the disk but it is not listed in the directory and might get over written at any time."
],
"score": [
46,
9,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b06yxr | Does “burning in” brand new audio gears such as headphones and speakers actually work? | Technology | explainlikeimfive | {
"a_id": [
"eicj1aq"
],
"text": [
"First: The word 'gear' in this context is already plural. It's a group noun, like 'news' and 'furniture'. Second: No. That idea comes from decades ago, when magnets were weaker and materials were worse. Even then, it had almost no impact on the sound. Only hard core audiophiles purported to hear a difference in sound quality. Modern sound equipment uses materials that do not change physical characteristics over time. The diaphragm, if there is one, will not stretch."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0b6xe | How do WIFI enabled lights work? | Are they drawing energy all the time? Or just when you turn them on? Or does the amount of energy used change when you turn them on? | Technology | explainlikeimfive | {
"a_id": [
"eidcc4q"
],
"text": [
"It'll be drawing enough energy to run the wifi card and microprocessor whenever plugged in, but will draw more power to run the light when switched on."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
b0bl78 | How can websites tell when you are using an Ad Blocker? | Technology | explainlikeimfive | {
"a_id": [
"eidj9vg",
"eidkmzp"
],
"text": [
"There are a few methods, one of the easiest ways is to have your advertention server serve a piece of Javascript and then check if it loaded. URL_0 uses this Method",
"A web page rarely consists of content that can be loaded by a single web request. There are usually many round-trip requests to load a single page. If an earlier request inserts some code that should cause the browser to make a known later request plus some additional code run by your browser to check if that other request was made, it can tell if you blocked the \"tracer\" ad request."
],
"score": [
5,
3
],
"text_urls": [
[
"https://www.detectadblock.com"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0d21o | if my internet speed is 500mbps download, why do my devices download at less than 10% of my internets capability? | I'm trying to download an update for my Xbox One and it's taking a long time. I have Fios and the Google Mesh router. Everything is connected great with 500mbps download, but the update is only at 20-30 mbps. | Technology | explainlikeimfive | {
"a_id": [
"eidqkmr",
"eidqlxn",
"eidtttd"
],
"text": [
"Well, first of all, your speed will be limited by either your download speed or the uploaders upload speed, whatever is slowest. If the Xbox network only allows you to download at 30 Mbps, that's what you'll get. Secondly, there's a difference between MBps and Mbps. One MBps is 8 Mbps. So if your download speed is 500 Mbps, that's \"only\" 62.5 MBps.",
"Internet speeds are typically measured in mega*bits* while speeds shown in the download windows are usually in mega*bytes*. One byte is usually 8 bits so those speeds make sense.",
"Folks are correct about the Xbox upload speed and the bits vs bytes arguments. Both are true.There's also other bottlenecks along the way that mean you're often not going to get that 500mbps speeds.The first is that it's very likely they advertise \"up to 500mbps.\" Your connection is part of a larger network from your provider with limited capabilities. They assume most people are not going to be using up 500meg of bandwith at one time and so they often sell more bandwith than they can actually provide. For example lets pretend there's 10 people in your neighborhood with the same provider. Your provider has equipment capable of 3000mbps total. They can't handle all of you at 500 mbps, but they sell it to you anyway, because it's incredibly unlikely for all of you to need that bandwith at the same time. But, during a busy time, they're already at 2700mbps when you hop online. Well you're not gonna get 500 meg. Now figure that among hundreds or thousands of users and you can see where there are times where you'll be getting less than your full speed. Also equipment has bandwith limitations as well. Gigabit ethernet isn't actually 1000mbits under perfect conditions. Cable length, interference, hardware quality can all affect it. Routers and modems can only handle so much bandwith before they start to fall behind. This is why for high bandwith connections you have to have a docsys 3.0 or 3.1 modem. All of this can add up to make noticeable reductions to bandwith. Finally data transfer rates (like downloading a game from steam) measure only the amount of file data sent. Because of the way networking functions, this is broken down into packets and frames. Each packet and frame has data padded onto it (Like a destination, identifying information, etc). This still requires bandwith to send, but is usually not measured by things like steam. So there's a lot of additional little things that potentially further slow your connection."
],
"score": [
8,
4,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
b0d2rl | How does hanging up a phone call and calling again “fix” connection when the initial call was poor quality? | Technology | explainlikeimfive | {
"a_id": [
"eidt5aj",
"eie6xmb"
],
"text": [
"Telephone calls don't always take the exact same path from your phone to the phone at the other end. On a cell phone, hanging up and calling the person again will make your call use different radio channels, or even a different cell. This change will often clear up whatever interference or poor signal was causing the problem. One a wireline call, your call might have been on a pair of wires in the telephone central office that have gone bad. All of these central office wires are shared among the telephone users in your neighborhood, so a different pair of wires within the telephone central office might be used the next time you make that same call. The downside, is that *someone else* making a call might end up using the bad wires and get a poor-sounding call, until the telephone company figures out where the problem is and fixes it.",
"You know those puzzles where you have a bunch of points on the left side, and a bunch of points ont he right side, and a bunch of lines connecting them, and you have to find the path? That's more or less how phone calls work. The telephone company allocates you a line, and that is used as your connection between the two points. This is what operators did way back in the day. Now, sometimes the path they path they choose is experiencing difficulties, like some storms are in the area, or a raccoon chewed through a cable, or whatever. By hanging up and establishing a new line, you will (very likely) get a new path, which may or may not be better or worse than the first one."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0f9a1 | How does Spotify know what music I will like and generate those discover weekly playlists? | Technology | explainlikeimfive | {
"a_id": [
"eie7hud"
],
"text": [
"They track what you listen to, and match it up with what other people listen to. And more recently, they use machine learning to find songs and artists that are audibly similar in some manner. The models that result in people listening through the playlists are kept, and the others dropped. This is why you’ll get some really odd suggestions sometimes; you’ve effectively become part of the product."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0fhhq | How is it that new phone battery can last in stock for "long" periods but once used it will degrade much faster if not properly charged often? | Technology | explainlikeimfive | {
"a_id": [
"eieb2br"
],
"text": [
"Leave your phone at a 40% charge and turn it off, and it will last almost as well as when it was in stock storage."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0gbig | How does Google search pictures? | I've done a little bit of programming so I'm familiar with searching keywords in say a database which is basically what the internet is, but how do search engines compare images and how do they do it so fast? | Technology | explainlikeimfive | {
"a_id": [
"eiemmb8",
"eieva05"
],
"text": [
"1.The name of picture or the context in a webpage 2.When you search FLOWER and appears a FLOWER you click. This make Google learn, time after time, search after search, that the picture is a flower.",
"Originally it only did a regular web search for the keywords you inputted, and then grabbed images off of pages that mentioned those keywords a lot. So if you search \"dog\" and it finds a web page with 30 hits for \"dog\", any pictures on that page are pretty likely to be of dogs. This is still a big part of image search today, but I would guess it's also enhanced with machine learning now that can actually parse some of the semantic content out of an image itself."
],
"score": [
5,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
b0hes0 | How can a hot computer shut down and completely turn off the fans? Wouldn’t the heat hurt the components? Seems like they should keep running for a few minutes.. | Technology | explainlikeimfive | {
"a_id": [
"eieof2a",
"eieqj1f",
"eieodg7"
],
"text": [
"Once the power is turned off, no component is going to get much hotter than it was during operation. The hottest components will not get any hotter. The computer will cool down via convection and radiation even without fans.",
"Also when performing a proper shutdown the CPU for example does have a 'ramp down' the fans do still push air for a few seconds. As long as the component is below its max temp it's fine.",
"When the computer turns off it stops running electricity through the components so they stop producing heat. They can't magically get hotter internally so I'm not sure what the reason would be for a continuing fan cycle."
],
"score": [
10,
5,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0j8c0 | How far up into space must one go before a compass stops working, and what do they use at that point for navigation? | Technology | explainlikeimfive | {
"a_id": [
"eieztmi",
"eiezzpb",
"eifg2s6",
"eift9p9"
],
"text": [
"In the sense of it being a tool for navigation it would stop working pretty quickly, like before you leave the atmosphere. it might point north but that doesn't help you in a space ship. Once it leaves earths magnetic field it wouldn't do anything at all (no idea how big earths magnetic field is but farther than the moon)",
"The earth's magnetic field, like it's gravity, extends to infinity. The strenght of it decreases with distance to the point where it wouldn't have enough force to move the needle in a compass. Whilist close to the earth, spacecraft use special devices that interact with the magnetic field for orientation. When the field becomes too weak they use something called reaction wheels, or sometimes reaction control thrusters. While there are many devices to help orient a craft, some even using the magnetic field, to my knowledge it is not ever used for navigation as it only shows the direction to the closest pole, not anything usefull like altitude or speed or whatever. So back to the answer, the thing virtually all spacecraft use for navigation is gyroscopes, combined with a variety of other telemetry data and sensors, to provide accurate data for the mission planers to use. As many interplanetary missions showed, these are accurate within meters even at the largest of scales. Edit: my comment caused some confusion, so let me reitarate. Reaction control wheels, magnetic devices and rcs thrusters are used for attitude control, aka ship orientation. For knowing the position of a craft, most of the time gyroscopes are used, along with other sensors like accelorometers. Star tracking and some other means can also be used, but are not as common. Radio contact to earth and measuring the delay is also an option.",
"i love how \"explain like im five\" has now turned everything into \"explain to me like I'm an astrophysicist in the most complicated form possible\" lmao. oh reddit, never change",
"Most spacecraft don't need to know where they are, just to do a certain burn in a certain direction at a certain time, worked out and programmed before launch. Controllers will then monitor it from the ground using radar or signal tracking and make any corrections as they deem necessary."
],
"score": [
32,
24,
8,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0jer4 | what does "power cycling" a modem actually do? Why is it always 10-15 minutes? | Technology | explainlikeimfive | {
"a_id": [
"eif0kos"
],
"text": [
"Part of is resetting the modem, and part of it is resetting the connection. Resetting the modem is obvious - it's a computer, and sometimes computers have bugs which corrupt a portion of memory. Turning them off and on restores the defaults. Resetting the connection is a bit more complex. The ISP maintains some amount of state for your modem - it knows the modem's IP address (which is assigned dynamically when you connect), and each side has some information remembering agreed-upon details for the connection. Sometimes, one side or both screw up the connection state, and in this case the connection must be torn down. The longer gap is to make sure this reliably happens on your ISP's side, instead of the ISP's side just deciding that the connection is slow for a bit. [This page]( URL_0 ) has a bit more technical information."
],
"score": [
5
],
"text_urls": [
[
"https://blog.pilotfiber.com/why-your-isp-tells-you-to-reboot-your-modem"
]
]
} | [
"url"
] | [
"url"
] |
|
b0kzva | How do APIs work? | I kind of know that they allow two systems to talk to each other, but how exactly does that happen? Does each system's respective APIs connect to each other to form a pipe? Is it possible for one system to have no APIs and connect to the second using the second's APIs? | Technology | explainlikeimfive | {
"a_id": [
"eif9q63",
"eifmdxh",
"eife1jr",
"eig1vd0"
],
"text": [
"An API is a document that describes how you are supposed to talk to a computer system. You know. If you want to connect to it and talk, the document describes how. Everything from login credentials to error messages to what information you can pull out of it and how to behave to put information in is covered in the API. We can kind of demonstrate this by having a normal conversation about where to find the closest McDonalds when someone starts talking to you on the street. Hungry Person: \"Hello?\" You: \"Yeah?\" HP: \"Is there a McDonalds Nearby?\" You: \"Yeah?\" HP: \"Awesome, is it far?\" You: \"Nah. half a mile?\" HP: \"Awesome, in which direction?\" You: \"North.\" HP: \"How far was it again?\" You: \"Half a mile, perhaps.\" HP: \"Thanks.\" You: \"Good luck.\" Now. if you boil that information down to an API, you have to first establish a way to ask you questions. You know, can I speak french? Italian? Or is it just English? The API specifies that. You can *just* speak English. There is just one way to ask the question. And that is defined by an api version number you can ask for. That is literally the first thing the server says when you connect to it. \"I'm version 1.0\" can mean \"I only speak English\" or perhaps \"There is just one way you can phrase that question if you want me to understand it.\" Next, the API is for asking for directions to things. Is it *just* McDonalds? Any kind of burger joint? Any kind of restaurant? Just around here? Across the nation? Any business? THAT part doesn't have to be covered by the API. Your question has an answer. Or it doesn't. \"Is there one nearby?\". The server makes its own assumptions on what you actually mean when you say nearby. It's helping you to find shit nearby. There is one, or you get a no as a response. Then, the client wants to be sure that your version of nearby and my version of nearby is the same. so it asks for clarification? \"yeah, how far is it, then?\" And get a response. And then it asks for the actual direction. Because maybe you don't really feel like driving to your mums hood around dinner time without popping by, so you ask again. then, you know. Why would you ask about the distance again? This is where an API differs from a conversation. There is no point in asking for the same information twice. And then they agree that they are both all good and want to stop talking. so they end the conversation. API's can be simple. And complicated. They can cover really complex things. And they can do several thousands worth of a very simple thing by sending a huge list of simple tasks that it wants to have done. A bank for example that connects to another bank has an API that they talk through when the systems talk: \"I have a list of accounts that we are sending money to.\" \"Alright. toss that list over.\" \"It's 200000 transactions.\" \"That's fine, I'll take it.\" \"Here it is.\" \"Ahem, there is something broken with transaction 12453. We didn't do that one. Or any of the ones after. Fix your damn list.\" \"Uh, yeah. Sorry about that. Bye.\" Or when a power company's operational centre computer connects to a circuit breaker: \"Hi.\" \"Uh, hello there. I am the circuit breaker that you have named X45t7.\" \"I'm your master.\" \"Yeah, I acknowledge that you are my master. What is your command?\" \"I request a full status report.\" \"I am currently CLOSED and has been for 950 043 minutes. ...What is your command?\" \"Actually, I just wanted the status. bye.\" The API's define what the systems can say to each other. And how they say it. Generally speaking, it's the server that has an API. And the client is supposed to follow it. The API is the definition on how the server will talk. What it will say. If there are different ways to say the same thing. How you ask it for information. How you give it information. What the responses mean when it says them.",
"An API is a way to use a piece of software without needing to know how it works. * Software is a restaurant kitchen. If you want some food, and all you have is access to the kitchen, then you need to know how both how the kitchen is organized and how to actually make the food yourself. * An API is the front end of the restaurant. You still have to know how to get to the restaurant and how to read the menu, but then you can just order. The menu lists what all of your options are, the wait staff takes your order to the kitchen, everything is cooked and served, and you got what you wanted without ever needing to learn anything about the kitchen.",
"An API is simply a list of commands, definitions and protocols that a software exposes to the outside world for communication. Imagine it like the internal phone line of a company. You cannot directly call the CEO, but you can use a public phone number to connect to the switchboard, and ask to be connected to the CEO. A system can easily not have an exposed API, which in practice mean no other system can \"talk\" to that system of it's own accord: but that system *can* connect to other systems or use their data if they have an API. All an API is is \"Here is how you can talk to me, what commands you can give, and how I will respond\". An API simply abstracts away what is really happening and gives you an easy set of buttons to push to get the system to do what you want. A dog could be described as having an API when considering the commands you teach it: You can say \"Speak!\" and the dog will bark, but you yourself don't have to worry about the exact biological processes that allow the dog to bark: you just know how to trigger them. Same with \"Sit\", \"Come\", and \"Stay\".",
"Imagine you have a bank that stores valuables for customers. Your customers are entitled to deposit or retrieve their belongings whenever they want, but you can't just let people wander into the bank because they might take something that isn't theirs. Instead of letting them have free access, you make them go through tellers. The customer tells the teller what they need, and proves that it's something they're authorized to do, and the teller goes and gets it for them. An API is kind of like that, except instead of a bank it's a database or some other protected system, and instead of a teller it's an interface such as a series of methods that they use. The reason you build an API is the same as the reason a bank has tellers: You want customers or partners to have access to things so they can build cool stuff with them, like games integrating with Facebook or job hunting sites integrating with LinkedIn. However, you don't want to give them total unlimited access in case they do something bad, so instead you build an API which has total access to the system (since you built it), but restricts what the user can do. As for how they work on a technical level, that depends on the specific API implementation. A lot of times it's like a public wrapper around something private. For example, if I have an online database I want people to have indirect access to, I might build a set of PHP web services that access the database directly, and people are able to access those but not the database itself."
],
"score": [
8,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
b0mf32 | Why do electrical appliances such as alarm clocks have so few buttons, wouldn't it make more sense (and simplify setting up) to have a button to activate each feature (brightness, alarms, time, date, radio)? | When I need to change a setting on my clock I have to tab through every other setting before I get to the one I need and even then I sometimes tab past it and have to go around again.... | Technology | explainlikeimfive | {
"a_id": [
"eifjgyv"
],
"text": [
"I actually work on the automotive industry, so not actually appliances but I believe the reasons are the same. Quick answer: saving money Long answer: most of the appliances we use at home are produced in large quantities and believe it or not, currently the most expensive items on an electronic device bill-of-materials are actually buttons, displays and connectors and not the chips themselves. Essentially these items are limited to the minimum possible to decrease the material costs. Other indirect reason is the electronics board (PCB) space. Too many buttons and switches actually cost a lot of circuit space which also costs money; less buttons = less space needed = less costs = more profit."
],
"score": [
21
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
b0nrm5 | How did sending messages on birds work? | Technology | explainlikeimfive | {
"a_id": [
"eifspuo",
"eiftbmo"
],
"text": [
"The birds only fly home. They can navigate to their home from thousands of miles away. So you raise them in one particular place, and take them with you in a little cage when you go off to invade some other country, and when you needed to send a message you tied it to the bird and let it go, and it flew *home*, where someone was waiting to see if any birds with messages flew back. It wasn't 100% reliable, but you could send multiple birds and the distances they could fly and still get home are pretty amazing.",
"This was done only with carrier pigeons. These are pigeons that have been specially bread to return home after they have been released. So you could go to a carrier pigeon breeder and get a few pigeons. These would be carried in a cage for days or even weeks on end. When you want to send a message back home you write it on a piece of paper. This is then secured to the leg of the pigeon and the pigeon is released. It will make its way back home to the pigeon breeder. He will get the note from the pigeons leg and read it. He can then pass the message on. You can see how useful this is for example if you have an army marching around trying to out maneuver the enemy but needs to tell the cities where they should send the supplies and reinforcements to."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0nsbo | You know those glass windows that can blur at the press of a button? How do those work? | Technology | explainlikeimfive | {
"a_id": [
"eift6bt",
"eifzrtq",
"eig82x4",
"eig37yz",
"eigadoh",
"eig0dxm",
"eihwx6d"
],
"text": [
"As I understand it they use liquid crystals like in LCD screens. When a voltage is applied, they all align and let light through. When they're not energized they just go in whatever random direction and disperse the light. & #x200B; Edit: Gold? Gold! Thank you, anonymous stranger.",
"There are a few ways to do it. u/duck1024 described what is usually called a Suspended Particle approach. Its a straight forward approach that can be tuned but needs constant voltage. However, on top of that, there is the electrochromic approach. Electrochromics work by a burst of electricity through a material that physically changes colour when it is exposed to electricity (its similar to react-to-light lenses in a pair of glasses, except rather than reacting to light, they react to electricity). Once the pigment changes, it stays changed until another burst is applied. They also darken to a grey shade, don't got completely opaque, and can sometimes take minutes to change. Edit: spelling is hard",
"I see this has been answered but I wanted to chime in since I own a company that installs a lot of this product. & #x200B; The technology is called \"PDLC\" or polymer dispersed liquid crystal, commonly referred to as \"Smart Film\" or \"Smart Glass\". There are a ton of liquid crystals suspended in a polymer solution which is laminated between a PET coating. When electricity is applied the liquid crystals all orient into the same direction, allowing transparency. When electricity is removed, the crystals disperse back into a mixed state. The film works opposite from what most people assume, with electricity making the film clear. Most people assume you are turning the film \"On\" when it is frosted, so we typically install the switch upside down. That way, when a client wants to add privacy for their office, boardroom, etc, they flip the switch \"on\" but are actually turning the product off. & #x200B; The film (we install the film version, there is glass as well, same technology) uses about 0.4 watts a square foot, so even a large installation, if left powered constantly, draws very little power. & #x200B; Although the film looks very clear when powered, there can be quite a bit of haze when clear. Cheaper products have more haze. Even the best products have an optimal viewing angle of 90 degrees, so viewing from the side, or from top down or bottom up you will notice haze. You are literally looking at the side of the crystals when out of optimal viewing angles. Lighting can also play a part in the amount of haze, as light will reflect of the crystals. & #x200B; It is expensive, expect to pay between $75-$100 a square foot for product and installation. & #x200B; Let me know if you have more questions! I play with this stuff all day!",
"Does anyone know why this hasn't been implemented as a way to tint car windows?",
"Since we're on the subject, what are they called and can I get some? How expensive would it be?",
"I don't know those windows. Have you got a link to what you're talking about?",
"I actually made a presentation about that kind of glass. It is called smart glass or also known as switchable glass. The light transmission of the glass gets affected when electricity, heat or light is applied. Between two glasses is a thin liquid film laminate of rod-like nano-scale particles. When no voltage is applied, the suspended particles are randomly organized - > blocking and absorbing the light. When there is voltage applied, the suspended particles align and let light through. This glass can be used manually and automatically to control the light which gets through. & #x200B; That is of course only a short explanation. I hope you understand what I say in this post - sorry for my bad english!"
],
"score": [
12934,
1191,
137,
34,
19,
14,
4
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0nv2b | How do experts believe superintelligence will emerge and engage with humanity? | Technology | explainlikeimfive | {
"a_id": [
"eifw2j5"
],
"text": [
"**Short answer**: There is no answer. The moment that a superintelligence exists is also the moment that we cannot predict beyond. **Long answer**: The idea of the \"technological singularity\" says that as soon as an AI superintelligence comes into existence it will immediately figure out how to make itself more intelligent, do that, figure out how to make itself even more intelligent, do that, etc. It will quickly surpass the limits of human intelligence, which means we can no longer predict how it will interact with humanity. There are people arguing pretty much every possible side of the discussion, so you could pretty much pick any outcome you liked and find some expert or another that supports that outcome."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0o4y8 | What is big data clustering? | Technology | explainlikeimfive | {
"a_id": [
"eifxy5f"
],
"text": [
"First, big data is just a buzz word, and just means any large amount of information. Suppose you have information about a few objects, some apples, fire trucks, and tangerines. We could take two pieces of information about these objects, the color (red or orange) and the shape (round or square) and use them to determine which items belong to which groups. Some fire trucks will be redder than others, and some apples maybe be less round, but they all should exist in similar places in red/orange-round/square considerations. The clustering means that we determine limits as to when an object is more likely an apple, tangerine, or fire truck. If the object is redder than an upvote and round, it must be an apple. We would want to create categories for these so if we get a new object, we can label it as an apple, fire truck, or tangerine based on what we’ve seen before."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0oz4t | How does your phone not get into a sound-feedback loop when on speakerphone? | Technology | explainlikeimfive | {
"a_id": [
"eig2dlr"
],
"text": [
"There's a process called \"echo cancelling\". Basically, the sound that's being sent out is also flipped 180 degrees out of phase and fed into the microphone circuit. There it cancels out the sound from the speaker that's being picked up by the microphone."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0p3az | Why does Google Chrome have ~10 or more processes running at all times even if I don’t have many tabs open? | Technology | explainlikeimfive | {
"a_id": [
"eig418c"
],
"text": [
"Chrome uses different processes not just for tabs, each extension also gets its own process and there are a couple of additional utility processes. You can see which processes are running by opening the Chrome task manager (Chrome menu > More tools > Task manager)."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0pasx | How do they create bullet holes and make glass shatter for movies? TO my knowledge some are real and not CGI? | Technology | explainlikeimfive | {
"a_id": [
"eig520c"
],
"text": [
"There are \"squibs\" which simulate bullet hits on people or surfaces. They don't fire live ammunition for movies. Safety glass can be made to shatter - often it is made out of materials other than glass."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b0rg7m | How do electronic devices (phones/smartwatches) keep track of time when their batteries die? | Even when not connected to the internet, booting up a device that has kept time is super cool. | Technology | explainlikeimfive | {
"a_id": [
"eiglw9l"
],
"text": [
"They have a second battery. Many electronic devices like computer motherboards have circular watch batteries for the sole purpose of keeping time and a few basic configuration settings when the power is off."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
b0vloi | What’s so special about a Tesla Coil? | Technology | explainlikeimfive | {
"a_id": [
"eihk3u1",
"eihrsof"
],
"text": [
"It raises the voltage of an electric current. This allows the electricity to jump out to other objects. This creates flashy lightning. Humans tend to be interested in flashy shiny things.",
"They are strong against tanks, infantry and whatever else land units the enemy throws at you in Red Alert."
],
"score": [
28,
21
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0wrj8 | What exactly do game studios have to do to port a game made for console to PC? | Technology | explainlikeimfive | {
"a_id": [
"eihs9da",
"eihvy0b",
"eiht52f",
"eii6umc",
"eii14rd"
],
"text": [
"Games are computer programs. And computer programs are written as a series of commands that humans can understand, like 'jump character ' in so called 'high level languages'. These are then converted by a program called a 'compiler' to a series of 1 and 0 called 'machine code', which is what computers can process. Depending on the the specific capabilities and design of the computer you wish to run the program on, there are different compilers. For example, on one computer, the command for 'jump character' may translate to a machine code '01001', while on a different computer it may be '10011'. On still another computer, there may be no 'jump character' instruction at all. Rather there is instead a command 'move character up' and 'move character down'. A jump would rerequire moving the character up and down really fast. These changes have to be made by the creators of games to ensure that their game runs on a different computer. The process is called 'porting'. Porting can be very hard or very easy depending on the specific design and high level langiage platform that the games are written in. It also depends on how similar or different the two computers which are being targeted are in terms of capabilities.",
"It's all about the **Game Engine** these days. The engine is what runs the game, it handles things like drawing the geometry, adding the lighting, taking user input, moving the character, animating the enemies etc. Very few games are written without a game engine. So if the game engine exists on the new platform, it's usually not too hard. For example, Unity (A very popular game engine for indie / small studio development) will run on many platforms. For these, you often just load your game file into the engine and make some changes to suit the new hardware - some hardware can handle less detail or slower frame rates which require small changes to the game. For AAA games the Engine is usually in-house, so if they are converting the game to a new platform they may need to convert the game engine first which is a huge task. That is actually a program and the internals could be quite different from one platform to the next.",
"To start off, they'd simply copy all of the game code and put it on the PC. For the most part, any part of the game that only deals with *itself* doesn't need to be changed. This would also include: Art, music, levels, animations, AI, etc What *would* need to be changed are the parts that talk to the operating system. Basically, a game wants to say: \"Give me a window to drawn on\", \"Let me give you sound output\" and \"Give me input from the keyboard/mouse/gamepad.\" So, a console game would need to be changed so it knows how it ask for and perform those things. (Though, depending on the game engine used, these things may already be done and they simply could push an \"Export for PC\" button.) In addition, there are little things that are expected to be changed (Lazy games studios don't always to this to the grief of players) which include changing the hints shown in game from game-pad icons to keyboard and mouse, also, adding PC specific options like full-screen mode and other graphic settings. This is just a basic overview really, in the real world, there would likely be many small adjustments and issues that would need to be fixed.",
"Your game is a program. Think of a program as a job. Anybody can do this job, if they can understand the instructions. Consoles and PCs don’t speak the same language, so if you want to port a console game to pc, you have to either rewrite all of the instructions in a language the pc understands, or supply a translator (emulator) to translate all the instructions on the fly.",
"20+ years ago, games would have to be completely re-written to port a game from one platform to another. The reason for this is that developers had direct access to the hardware, so they would write the code to expect a very specific machine to run on, and to issue very specific instructions to that hardware to make things happen on screen, play sounds, register input from the player and so on. Those same instructions would mean nothing to another machine, so a Megadrive (or Genesis) game wouldn't run on a SNES even if you found a way to insert the cartridge. This is obviously VERY inconvenient, but was necessary because machines back then were slow, and you needed to hand-code every instruction to get maximum performance. Then computers got faster, and people started implementing *abstraction layers*, programs that handle all the tricky stuff for you and you just ask them to do things for you. Its slower to do things this way, but the performance hit was relatively tiny given the increased power of the machines so the convenience massively outweighed the drawbacks. These *abstraction layers* would be your *operating system*, and *drivers*. If you want to draw a picture on the screen in a Windows environment, you don't issue instructions to the CPU or GPU directly, you ask Windows to create a window to hold the image, and then you ask the graphics driver to draw the image, and the driver handles the bit where it issues commands to the hardware. The result is that software is way more portable, because your code is no longer expecting a specific CPU or GPU in order to work, it is instead expecting a certain operating system or set of drivers who can then talk to any number of CPUs for you. So to answer your question, nowadays porting games requires three things: First it needs to learn how to talk to Windows and/or Linux, because Xbox One and PS4 have their own operating systems which work in different ways and have different rules. So the game has to understand how it should start up in a Windows environment, this would be things like where the \"entry point\" to the program should be so Windows knows where to start running the program. Secondly, it needs to talk to the drivers correctly, so it knows who to speak to about drawing stuff on the screen and playing sounds. Most consoles nowadays share things like DirectX with PCs for drawing graphics, so often they already speak the same language and not much porting is necessary. The third and biggest task however, is optimisation. When working with a console, developers know exactly what the machine is good and bad at, and they can write their game to exploit this. On a PC however, you have a much wider variety of machines to run on. Some people might be running an AMD video card with 4gb of VRAM, some will be running an NVidia card with 8gb of RAM. Some people will have a quad-core CPU at 3.0ghz and others only dual-core but clocked at 4.5ghz. Sometimes developers will need to re-write the renderer in order to be more flexible and work on a wider range of PCs, which is where you end up seeing really shoddy ports that run badly on PCs."
],
"score": [
58,
25,
11,
7,
5
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0x1yz | Why do people use the color 'green' for greenscreen and not any other color? | Technology | explainlikeimfive | {
"a_id": [
"eihre8g",
"eihrix3",
"eihrelp",
"eihrea1",
"eihtq0i"
],
"text": [
"Green screen effect it actually called Chroma Key. Green is most often used because it does not match any natural hair or skin color, so it's the safest bet for not keying out any part of your actor.",
"They do use other colors actually!!! Green is the usual though because it doesn't match any natural skin tone or hair color, meaning no part of an actor will be edited out through chroma key. If there is a green costume or prop, a blue screen will be used instead",
"Because it doesn't conflict with various skin tones or natural hair color. This article explains it well. URL_0 have a read.",
"They use different colors based on what they are trying to film. But green is because there is not much green in humans. :P",
"The greenscreen is for something called Chroma Key. Where they edit out anything that has that exact color. There are three primary colors. Red, Blue, and Green. Human skin has a slight reddish tint, but contains very little blue or green, so they don't use red. Blue screens do exist, and infact predate the green screen. The switch mainly had to do with alot more people wearing blue than green."
],
"score": [
28,
20,
7,
4,
3
],
"text_urls": [
[],
[],
[
"https://www.google.com/amp/s/theconversation.com/amp/ive-always-wondered-why-is-a-green-screen-green-92989"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b0xmd3 | How every pixel of a display is controlled individually? | I mean how the system controls every single pixel is controlled without using millions of different cable going each pixel? Don't they need different cable for every pixel? How can the pixels have different colors on while they aren't being controlled by different cables? I can understand the amoled screens because they have self illuminated pixels but how do lcd screen controls pixels? | Technology | explainlikeimfive | {
"a_id": [
"eihunl5",
"eii2fci",
"eiihqxs"
],
"text": [
"> I mean how the system controls every single pixel is controlled without using millions of different cable going each pixel? It does uses \"millions\" of different cables. They are just very short and tiny. And it is the same with OLED, LCD, AMOLED etc.",
"There are very thin wires down and across the screen. For example, a 4K TV is 4096 × 2160 pixels. It has 4096 vertical wires and 2160 horizontal wires. Where they intercept is a pixel. A pixel is control by activating one row and one column wire. For a 4K TV with a refresh rate to 60 Hz, each pixel must be controlled in 1.88 nanoseconds (0.00000000188 seconds). Pixels have one one colour: red, green, or blue. They are packed so close together that your brain merges them into one pixel. But sometimes you can see coloured fringes on objects. That is why screen are constantly getting more and more pixels. To make such anomalies disappear.",
"Yes. Each pixels have usually two \"cable\" to power it. Although they are more like a ultra thin metallic trace on the glass (that's the number one reason why there is a tiny gap between them). Now, to avoid having that amount of cables dangling from your screen to your video card, we employ two techniques: serialization, and memorisation. Serialization is why really old printer cable where \"parallel\" cables with a crazy amount of pins, while new printer cable are USB cable with just 4 wires. The idea is simple: you have 2 million pixels to send, 60 times per seconds. You can either have 2 millions cable to send each pixel in parallel, and you keep that up for a 1/60 of a second so that they stay on. Or, you can send 2 millions pixels, one after an other, on a pair of wires that run at 120 MHz (that's 60Hz x 2 M). But then, only one pixel stays on for a miniscule fraction of a second, and you rely on eye persistence of vision... Or: Memorisation allows you to put a tiny memory behind each pixel so that they remember their color for 1/60 of a second. Then you get the advantage of both: few cables, and stable image. But the screen is more expensive as you need a memory on each pixel."
],
"score": [
8,
6,
6
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
b0xz49 | What makes greenscreens work and why exactly they are green? | Technology | explainlikeimfive | {
"a_id": [
"eihw6n3"
],
"text": [
"You simply hide every pixel that has that green color. Make it transparent. Green is used because it has a nice contrast to humans. But really any color can be used. Blue is also seen often, orange and red are more rare since human skin is to close to it."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b11ih0 | Why do digital devices slow down when they get old? | Technology | explainlikeimfive | {
"a_id": [
"eiijtuj",
"eiijvg8"
],
"text": [
"The main reason is that programms and apps require better hardware as they get updated. It’s not really the digital device that slows down, but the updated software is just to heavy to run on the outdated hardware",
"Most computers these days don't have any moving parts, everything is a chip. For this reason, they don't really wear out. The reason they \"slow down\" is because the software is updated with new features they require more and more resources like processing power and system memory. & #x200B; They can also appear to slow down even running the old software because we get used to other newer devices that do more and do it faster or smoother than the older devices."
],
"score": [
12,
7
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
b11o14 | On programs such as photoshop, increasing the size of a picture beyond what it already is lowers the quality of it. How do small projectors manage to create a relatively high quality picture from such a small display? | Technology | explainlikeimfive | {
"a_id": [
"eiilwdk"
],
"text": [
"Projectors have lenses that designed to create high quality images at a certain distance. If you try to project smaller or larger the image starts to go out of focus. On professional projectors designed for large live events you can swap in a different lens but increasing the size of the projected image will cause the light spread out more and so the image will not be as bright which can contribute to a loss in quality."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b143fh | Why doesn’t a battery or electronic device charge instantly up to 100% when you plug it in? Also is this technology coming in the near future? | Technology | explainlikeimfive | {
"a_id": [
"eij5d7l"
],
"text": [
"The electricity that you get from a charged battery works because some chemical reaction gradually moves electrons from one side of the batter to the other, causing a voltage across the batter. As more and more atoms react, they lose the ability to move electrons this way. For some materials, reversing the voltage on the battery can cause the electrons to move back, and reverse the chemical reaction, but just like it takes time for the reaction to happen in one direction, it takes time to reverse it to. For materials that can be charged quickly (like smaller capacitors) they also discharge quickly. You can't have one without the other. Sometimes you can charge the battery faster by increasing the charging voltage, but if you do it too fast, the chemicals in the battery will get hot, and have a tenancy to light on fire. This is why batteries get hot when you charge them. There will certainly be better batteries in the future, but right now battery technology is moving at a bit of a crawl. It's hard to say what will happen next. Edit: Correction from u/EightOhms You don't reverse the voltage, you just put it under voltage."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b14jek | How do 3D movies work? | Technology | explainlikeimfive | {
"a_id": [
"eij7ygp"
],
"text": [
"Seeing \"3d\" works by the brain taking two slightly offset images, one in each eye, and combining them to understand depth. A 3d movie will shoot the movie with a camera with two sensors at a slight distance apart like the eyes, effectively giving a \"left\" version of the movie and a \"right\". Then you have a special projector that can give the right sided image to the right eye. Currently, this is done often by polarizing the one image differently than the other, and have the viewer wear glasses that block the image you don't want in each eye."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
b14k4n | Regular software tends to have a lot of bugs and mistakes, how do programmers write software for things like airplanes or rockets where there can't be any errors? | Technology | explainlikeimfive | {
"a_id": [
"eij7lme",
"eij7jk1",
"eij7677",
"eijf7ln"
],
"text": [
"They do a lot more testing and re-testing. They also write code is much less complicated than regular code. It does only what it needs to do and nothing more. This reduces the changes for errors. Also the systems are built with fail safes. The hardware has something called a watch dog timer. When the timer runs out it checks that a certain condition is met ( this is called a flag). If the flag isn't set then the timer automatically reset the system to a safe state. & #x200B; Programmers know this will happen so they write their code so that it sets the flag when their function finishes. This way if the program ever gets stuck in a loop, the system will automatically reset to a safe state if the the loop doesn't clear in a certain amount of time",
"When software is written, a huge, huge, huge chunk of time is spent debugging and testing it. When we test our programs, we essentially compare its outputs to expected results. For example, if I write a program that adds two numbers, I can compare it to actual value of adding the two numbers. But you seem to think that all software produced is flawless. It’s not. At all. Because it was tested against tests written by humans. It’s prone to mistakes and we see that all the time. There are many cases of rockets crashing a second after flight because of badly written code that clearly wasn’t tested properly. When something we do succeeds, it might actually produced perfect expected values or it might produce “good enough” values. The quality of your software depends on how thoroughly you tested it for producing the correct expected values",
"you keep it super simple and validate it for much much longer. for things like hardware, you use redundancy.",
"One thing that's not mentioned here is that in planes, there are two different computers running code that was written by two different teams (all working with the same inputs and outputs and rules). That can significantly reduce the chance that a single human error would cause a catastrophe. & #x200B; In rockets, it may be the same, but it might not. I heard that for the curiosity rover program the program was massive like 100s of thousands of lines. That would be nearly impossible to test. Instead they wrote another program that would write flawless code. Since that program was much simpler, they could test it 100% (or nearly)."
],
"score": [
15,
12,
5,
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.