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2,429 | History, or Hx, remains a little perplexing to me. Can you explain how it works, both mechanically and fictionally, in a way that makes sense? I am especially hung up on integrating History changes into the fiction, because I don't understand how to rationalize a shift from +4 to +1, for example.
Thanks! | 2010/09/08 | [
"https://rpg.stackexchange.com/questions/2429",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/387/"
] | History (Hx) is a measure of how well you know someone. Fictionally this might be knowing secrets about them, understanding how they think, knowing their history of violence and being able to predict what they might do, knowing how to work smoothly with them, and/or knowing how to push their buttons or poke their raw emotional wounds and thereby manipulate them. The game doesn't require that you detail this, but you'll probably start with a vague idea anyway.
All together, those kinds of fictional foundations for "how well do I know them?" gives you a certain amount of hold over them, represented mechanically by the Hx rules. When they are trying to do something, you can describe how you help them or interfere with them. If it's fictionally sensible, then you roll+Hx to apply the +1 (for help) or -2 (for hindering) to their roll. The rules recommend rolling at the same time, but it's not strictly necessary.
History changes in three ways. With the ***end of session*** move, each player picks a PC who they think knows their character better than before. Usually it will be obvious, but occasionally they'll have to think about it. Either way, once they choose it will probably be obvious how the fiction is related to this change. This won't require any special handling to represent in the fiction.
The other way is the rollover when your character's Hx hits +4 with another PC and has to reset to +1 (while getting to mark experience). The rollover from Hx+4 to Hx+1 can be thought of as a new "level" of understanding of someone. You've had a small epiphany about how they tick, but now you're in slightly uncertain territory with them while you integrate this new understanding. Mechanically, your enhanced knowledge of them turns into marking for improvement (which generally makes you more competent, including when dealing with that PC), and allows you the chance to build up your understanding of them again.
The third way Hx can change is due to a classe's special move triggered by sex, but those are self-explanatory when it comes to the fiction. | I think History is sort of a confusing term for this stat, because -- as you note -- it can go down, and how do you get less history with someone? What it really means, as per page 103, is how well you know someone. So maybe I met you yesterday, but it was the most important life-changing day you've ever had and I spent the whole thing with you. I could easily know you very well, and accordingly have a high History. Or I could have known you my whole life, but you're just that guy who lives in the next shack over, and I never knew you were an axe murderer. Low History.
So if I change a lot, you don't know me as well.
This doesn't entirely satisfy me as an explanation, given that my History stat with someone can go from +4 to +1 at the end of a session, and there are mechanical incentives to make that happen. On the one hand, I can decide that I don't want to make that move because I don't know how to play it out in the fiction. On the other hand, then I'm passing up advancement.
In play, I'd want to link that change to whatever advancement I was thinking about. I know when I change in real life, my opinions on people change, and sometimes I look at them in ways that make it harder to empathize. Hey, I just got a gang -- now I'm thinking about them more than I'm thinking about you, and I've kind of lost touch with you. I've lost my knowledge of you, because I'm not exercising it.
Short form: "It's not you, it's me." Which is a cliche but there's something in it.
All **that** said, +4 to +1 isn't always directly linked to an advancement, since it doesn't always generate the fifth circle of experience. I think this still works as a method of foreshadowing your expected changes, though. |
2,429 | History, or Hx, remains a little perplexing to me. Can you explain how it works, both mechanically and fictionally, in a way that makes sense? I am especially hung up on integrating History changes into the fiction, because I don't understand how to rationalize a shift from +4 to +1, for example.
Thanks! | 2010/09/08 | [
"https://rpg.stackexchange.com/questions/2429",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/387/"
] | History (Hx) is a measure of how well you know someone. Fictionally this might be knowing secrets about them, understanding how they think, knowing their history of violence and being able to predict what they might do, knowing how to work smoothly with them, and/or knowing how to push their buttons or poke their raw emotional wounds and thereby manipulate them. The game doesn't require that you detail this, but you'll probably start with a vague idea anyway.
All together, those kinds of fictional foundations for "how well do I know them?" gives you a certain amount of hold over them, represented mechanically by the Hx rules. When they are trying to do something, you can describe how you help them or interfere with them. If it's fictionally sensible, then you roll+Hx to apply the +1 (for help) or -2 (for hindering) to their roll. The rules recommend rolling at the same time, but it's not strictly necessary.
History changes in three ways. With the ***end of session*** move, each player picks a PC who they think knows their character better than before. Usually it will be obvious, but occasionally they'll have to think about it. Either way, once they choose it will probably be obvious how the fiction is related to this change. This won't require any special handling to represent in the fiction.
The other way is the rollover when your character's Hx hits +4 with another PC and has to reset to +1 (while getting to mark experience). The rollover from Hx+4 to Hx+1 can be thought of as a new "level" of understanding of someone. You've had a small epiphany about how they tick, but now you're in slightly uncertain territory with them while you integrate this new understanding. Mechanically, your enhanced knowledge of them turns into marking for improvement (which generally makes you more competent, including when dealing with that PC), and allows you the chance to build up your understanding of them again.
The third way Hx can change is due to a classe's special move triggered by sex, but those are self-explanatory when it comes to the fiction. | SevenSidedDie is absolutely correct, but since the OP also mentioned "how to rationalize a shift from +4 to +1" I thought I'd share a technique which is used by many MCs, and goes further than the simple (but anticlimactic) rationalization of a "new level of understanding":
>
> When your Hx with a character goes to +4 and you reset it to +1, have that character's player tell you a secret about their character.
>
>
> When you tell a secret about your character, tell the other player something their character did not already know, either some weakness or habit, or some psychology they manage to puzzle out. This should be something more than trivial; if it can be used against your character in some way, if it's something the MC didn't know, or if it paints your character in a radically different light all of a sudden, all the better.
>
>
> If you're using Hx (or bonds or the equivalent) with NPCs, and you reset from +4 to +1, the MC will tell you a secret about that character.
>
>
>
AW creator D. Vincent Baker said he wishes he had included this idea in the book.
Original post on the AW forum:
<http://apocalypse-world.com/forums/index.php?topic=1883.0> |
12,342 | I recently had a garage do work on my 95 Mazda B2300 during which they replaced the faulty instrument cluster. When I dropped it off at the shop, it had approximately 170k miles on it. After they installed the refurbished instrument cluster, my truck has magically gone back in time to read 120k miles.
Should the garage have advanced the refurbished odometer to the correct mileage, or do I just need to keep track of the difference? I currently have the exact difference documented, so do I just need to report it to whoever I eventually sell the truck to? | 2014/09/17 | [
"https://mechanics.stackexchange.com/questions/12342",
"https://mechanics.stackexchange.com",
"https://mechanics.stackexchange.com/users/446/"
] | You shouldn't have any worry about it, necessarily. Keep the documentation as you suggested and pass it along to a new owner if that ever occurs. If you drive it until the tires fall off, this will never be a worry. You aren't trying to get over on someone and you didn't cause the discrepancy yourself. It is what it is and should be treated as such.
If you are truly worried about it, there are devices on the internet (eBay) which you can plug into your ALDL port and update the mileage (**NOTE:** Device I found at the time of this writ was: XTOOL PS300 CAR REMOTE ECU PROGRAMMER & MILES CORRECTION TOOL PS 300 ... I'm deign to a link to it on eBay because as an auction, the listing will be gone very soon). Personally I wouldn't go through the expense and trouble of it myself. | Yes, the odometer reading should have been placed at the correct value when the "new" cluster was installed.
You should return to the garage and have them correct the difference, as they should have done in the first place. |
12,342 | I recently had a garage do work on my 95 Mazda B2300 during which they replaced the faulty instrument cluster. When I dropped it off at the shop, it had approximately 170k miles on it. After they installed the refurbished instrument cluster, my truck has magically gone back in time to read 120k miles.
Should the garage have advanced the refurbished odometer to the correct mileage, or do I just need to keep track of the difference? I currently have the exact difference documented, so do I just need to report it to whoever I eventually sell the truck to? | 2014/09/17 | [
"https://mechanics.stackexchange.com/questions/12342",
"https://mechanics.stackexchange.com",
"https://mechanics.stackexchange.com/users/446/"
] | You shouldn't have any worry about it, necessarily. Keep the documentation as you suggested and pass it along to a new owner if that ever occurs. If you drive it until the tires fall off, this will never be a worry. You aren't trying to get over on someone and you didn't cause the discrepancy yourself. It is what it is and should be treated as such.
If you are truly worried about it, there are devices on the internet (eBay) which you can plug into your ALDL port and update the mileage (**NOTE:** Device I found at the time of this writ was: XTOOL PS300 CAR REMOTE ECU PROGRAMMER & MILES CORRECTION TOOL PS 300 ... I'm deign to a link to it on eBay because as an auction, the listing will be gone very soon). Personally I wouldn't go through the expense and trouble of it myself. | Altering the mileage reading on a motor vehicle (causing fraud) is a felony. Selling the car without notifying the buyer of the odometer change would be illegal. If you notify the buyer of the change, there is nothing illegal about it. No need to fix it. Just keep in mind that its behind for service intervals. |
3,672,539 | I've got a Windows 7 machine upon which I do both PHP/MySql Dev, and .NET/C#/Sql Server coding. Due to a recent re-install, I thought it might be an ideal time to try and keep my machine a bit cleaner rather than install both Apache and IIS, etc.
I installed VirtualBox, with Ubuntu 10.04 as the guest OS, with the plan to move my PHP development from my old Windows/Apache/MySql platform onto this virtual image. In addition to this, I want to add CruiseControl/phpUnderControl to my PHP development process.
So far I've got Ubuntu 10.04 installed with a LAMP stack, plus Netbeans for PHP, MySQL Workbench, etc, which is effectively the same as my old Windows dev set up, but I've now also installed SVN and CruiseControl (I've not installed phpUnderControl yet, but that is the next step).
My question is, can I use this virtual image as both my "local" development environment and as a build server, so that I don't need to clutter my native windows machine with MySql/PHP related software (meaning I can keep it nice and clean for .NET development)?
I imagine I'd need the virtual webserver to be able to serve both a "local" dev version of any given project I'm working on, as well as a staging version, which would build using cruisecontrol/svn commits?
Or should I separate my dev and build servers, perhaps keep the local development in windows, and only use the virtual image for the build server? or perhaps have two separate virtual machines for different purposes?
I'd appreciate some advice on the best way to set this up. One of the projects I want to work on is quite complex so I want to make sure I get this up in the right way before I start the project, so that I can ensure the project is well maintained with versioning, unit tests and continuous integration, should I ever need to involve other developers on the project. | 2010/09/08 | [
"https://Stackoverflow.com/questions/3672539",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/298993/"
] | If you are looking to keep your Windows box clean of MySQL/PHP tools then I'd strongly recommend the two VM approach. One desktop linux distribution for development with LAMP etc on it for the quick code/debug turnaround and one that mirrors your real server install (with the addition of svn etc) for your test builds.
This gives you huge benefits for both having a nice dev environment and more importantly having a test server that will reflect operation of your code on the live server. This way you can keep your dev environment VM up to date with the latest updates for the distribution (kernel, tools, etc) and hold the build VM at whatever application versions are on the live machine. This takes a lot of the guesswork out of "is it the new version of library X or my code?".
If you want to go slightly overkill you'd actually want 3. One for dev, one for SVN/continuous integration and one that exactly mirrors your server so you can test deployment/system configuration. | If you are considering having your VM for dev why not set it up exactly as you would setup your staging/production environment?
Furthermore you can setup your VM to host the code repository, and the web server, and then connect your tools that are local to your host machine (Windows). That way you can develop on your Windows box, connected to the VM.
This gives you the ability to do everything in your local environment while simulating the server environment in your VM.
VirtualBox does networking really well too, and you should be able to make your Windows host connect via the network to the server as if it were really another node on the network. |
55,477,050 | I didn't want to ask this question here. I asked it on superuser but didn't get an answer.
<https://superuser.com/questions/1420073/why-did-formatting-win-7-computers-to-windows-10-double-their-cpu-z-bench-score>
So I work at a company as an IT guy while I am doing my computer engineering degree. Doing hardware and software maintenance of computers is part of my job. I have had a weird experience with two of the computers. These two computers(one desktop one laptop) were the slowest computers in the company. The laptop is Dell Inspiron N5010 with i3 370M(2 cores, 4 threads) processor. The desktop is HP 500B MT with E5800(2 cores 2 threads) processor.
At first, both of these computers had windows 7 running on them. CPU-Z(1.87.0) benchmark of the desktop was 113(single thread), 227(multithread). The laptop was 82, 267.
After I formatted these computers with windows 10 and ran the same CPU-Z version benchmark, **I got exactly double performance with both computers. Both single threading and multithreading scores got doubled.**
After formatting with windows 10, desktop got 270, 510. Laptop got 180, 520.
What is causing this? Physical core number stayed the same. Logical core number stayed the same. I am baffled. | 2019/04/02 | [
"https://Stackoverflow.com/questions/55477050",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/4109266/"
] | Is it possible that you upgraded from 32 bit Windows 7 to 64 bit Windows 10?
According to [this FAQ](https://www.cpuid.com/news/51-cpu-z-1-79-new-benchmark-new-scores.html) under the point **What algorithm does the benchmark use...** they state that
>
> the 32-bit version keeps using the legacy x87 instructions, resulting
> in almost half of the x64 performance
>
>
>
edit: please remove question here because it is not about code. I answered on superuser as well | If the difference in speed is noticeable, it might have been an issue with the drivers on WIndows 7, or it might have had something to do with [huge pages](https://www.chaoticafractals.com/manual/getting-started/enabling-large-page-support-windows) (enabling huge pages could boost the CPU performance significantly).
If you can't notice the difference in speed/responsiveness, it might just be a bug in CPU-Z (Have you tried the newest version 1.88?).
Going from Windows7 to Windows10 should not on its own result in such drastic changes in performance, the CPU benchmarks should be pretty close. Windows versions are also important, I've seen tests between *Win10 1803* and *Win10 1809* which show approx 10% increase in FPS in favor of 1809 (but that's GPUs not CPUs). |
14,655 | Say you have a public ASP.NET (or Classic ASP) application on IIS with a script/page that needs to write or update files in a specific folder that is located within the web publishing folder tree.
1) What is the proper way to set this up?
My main concern is that I want to let the ASP/ASP.NET apps write to a folder, but I don't want regular http users to be able to PUT files into it. | 2009/05/29 | [
"https://serverfault.com/questions/14655",
"https://serverfault.com",
"https://serverfault.com/users/1602/"
] | First let me start by saying, I'm a pretty big believer that there is almost always a better solution than writing stuff out to disk. Whether it's writting the data to a database, or feeding web services, writing out to disk should be the last option.
That being said there are some valid reasons, but this is sort of tricky and dependent on why the app needs to write out the files.
Having the data written outside of where code is running from is an absolute requirement. Allowing end users to write to a path where the ASPX/asp engines can interpret/execute code is bad for obvious reasons.
Some other things that impact this are:
1. Whether you're running the worker process under a domain account or the standard network service. It's important to realize that when you grant the IIS\_WPG group write access to a folder, any ASP.NET application running under the default account on the server may write files to that folder. This is a less than ideal configuration on servers where muliple applications run especially when the applications are untrusted and/or running in an ISP/shared hosting environment.
2. Whether the generated files need to be web available or not. If your application is just writting out some non-web viewable files, simply creating the directory, granting the rights, and configuring the application to read/write to the correct place is all you need. If the application needs to write out web viewable files, (this comes up fairly commonly in content management scenarios) you need to create a virtual directory (without execute code/scripts rights) that maps to your writable directory.
3. Whether or not you're working in a load balanced / web farm environment. If your application is operating in a farmed environment and needs to write files to disk for some reason, you're presented with a whole new problem. How do you keep user generated files on webserver1 in sync with the files generated on webserver2? Doing it via some convoluted syncronization script is painful at best and riddled with race/syncro issues. The best way of implementing this is to create a share on a third server (idealy a cluster with some redundancy) and store the data there. If you're running your worker processes under domain accounts (Security Best Practice), you can even map to the share in the application without having a user/pass anywhere in the code or web.config (makes audit/security people happy). IIS also has the ability to map virtual directories to UNC paths, so this won't impact your ability to make this content web viewable. | Probably betting to look over on [stackoverflow.com](http://stackoverflow.com)...
Best practice is to put that folder OUTSIDE of your document root and have your app read from the file system. Otherwise, make the folder read-only except to the ASP[.NET] user and control the write priviliges with your app's internal authorizations. |
14,655 | Say you have a public ASP.NET (or Classic ASP) application on IIS with a script/page that needs to write or update files in a specific folder that is located within the web publishing folder tree.
1) What is the proper way to set this up?
My main concern is that I want to let the ASP/ASP.NET apps write to a folder, but I don't want regular http users to be able to PUT files into it. | 2009/05/29 | [
"https://serverfault.com/questions/14655",
"https://serverfault.com",
"https://serverfault.com/users/1602/"
] | **The App\_Data Folder**
To improve the security of the data used by your ASP.NET application, a new subfolder named App\_Data has been added for ASP.NET applications. Files stored in the App\_Data folder are not returned in response to direct HTTP requests, which makes the App\_Data folder the recommended location for data stored with your application, including .mdf (SQL Server Express Edition), .mdb (Microsoft Access), or XML files. Note that when using the App\_Data folder to store your application data, the identity of your application has read and write permissions to the App\_Data folder.
[What's new in ASP.NET Data Access](http://msdn.microsoft.com/en-us/library/06t2w7da(v=vs.80).aspx) | Probably betting to look over on [stackoverflow.com](http://stackoverflow.com)...
Best practice is to put that folder OUTSIDE of your document root and have your app read from the file system. Otherwise, make the folder read-only except to the ASP[.NET] user and control the write priviliges with your app's internal authorizations. |
14,655 | Say you have a public ASP.NET (or Classic ASP) application on IIS with a script/page that needs to write or update files in a specific folder that is located within the web publishing folder tree.
1) What is the proper way to set this up?
My main concern is that I want to let the ASP/ASP.NET apps write to a folder, but I don't want regular http users to be able to PUT files into it. | 2009/05/29 | [
"https://serverfault.com/questions/14655",
"https://serverfault.com",
"https://serverfault.com/users/1602/"
] | First let me start by saying, I'm a pretty big believer that there is almost always a better solution than writing stuff out to disk. Whether it's writting the data to a database, or feeding web services, writing out to disk should be the last option.
That being said there are some valid reasons, but this is sort of tricky and dependent on why the app needs to write out the files.
Having the data written outside of where code is running from is an absolute requirement. Allowing end users to write to a path where the ASPX/asp engines can interpret/execute code is bad for obvious reasons.
Some other things that impact this are:
1. Whether you're running the worker process under a domain account or the standard network service. It's important to realize that when you grant the IIS\_WPG group write access to a folder, any ASP.NET application running under the default account on the server may write files to that folder. This is a less than ideal configuration on servers where muliple applications run especially when the applications are untrusted and/or running in an ISP/shared hosting environment.
2. Whether the generated files need to be web available or not. If your application is just writting out some non-web viewable files, simply creating the directory, granting the rights, and configuring the application to read/write to the correct place is all you need. If the application needs to write out web viewable files, (this comes up fairly commonly in content management scenarios) you need to create a virtual directory (without execute code/scripts rights) that maps to your writable directory.
3. Whether or not you're working in a load balanced / web farm environment. If your application is operating in a farmed environment and needs to write files to disk for some reason, you're presented with a whole new problem. How do you keep user generated files on webserver1 in sync with the files generated on webserver2? Doing it via some convoluted syncronization script is painful at best and riddled with race/syncro issues. The best way of implementing this is to create a share on a third server (idealy a cluster with some redundancy) and store the data there. If you're running your worker processes under domain accounts (Security Best Practice), you can even map to the share in the application without having a user/pass anywhere in the code or web.config (makes audit/security people happy). IIS also has the ability to map virtual directories to UNC paths, so this won't impact your ability to make this content web viewable. | **The App\_Data Folder**
To improve the security of the data used by your ASP.NET application, a new subfolder named App\_Data has been added for ASP.NET applications. Files stored in the App\_Data folder are not returned in response to direct HTTP requests, which makes the App\_Data folder the recommended location for data stored with your application, including .mdf (SQL Server Express Edition), .mdb (Microsoft Access), or XML files. Note that when using the App\_Data folder to store your application data, the identity of your application has read and write permissions to the App\_Data folder.
[What's new in ASP.NET Data Access](http://msdn.microsoft.com/en-us/library/06t2w7da(v=vs.80).aspx) |
14,655 | Say you have a public ASP.NET (or Classic ASP) application on IIS with a script/page that needs to write or update files in a specific folder that is located within the web publishing folder tree.
1) What is the proper way to set this up?
My main concern is that I want to let the ASP/ASP.NET apps write to a folder, but I don't want regular http users to be able to PUT files into it. | 2009/05/29 | [
"https://serverfault.com/questions/14655",
"https://serverfault.com",
"https://serverfault.com/users/1602/"
] | First let me start by saying, I'm a pretty big believer that there is almost always a better solution than writing stuff out to disk. Whether it's writting the data to a database, or feeding web services, writing out to disk should be the last option.
That being said there are some valid reasons, but this is sort of tricky and dependent on why the app needs to write out the files.
Having the data written outside of where code is running from is an absolute requirement. Allowing end users to write to a path where the ASPX/asp engines can interpret/execute code is bad for obvious reasons.
Some other things that impact this are:
1. Whether you're running the worker process under a domain account or the standard network service. It's important to realize that when you grant the IIS\_WPG group write access to a folder, any ASP.NET application running under the default account on the server may write files to that folder. This is a less than ideal configuration on servers where muliple applications run especially when the applications are untrusted and/or running in an ISP/shared hosting environment.
2. Whether the generated files need to be web available or not. If your application is just writting out some non-web viewable files, simply creating the directory, granting the rights, and configuring the application to read/write to the correct place is all you need. If the application needs to write out web viewable files, (this comes up fairly commonly in content management scenarios) you need to create a virtual directory (without execute code/scripts rights) that maps to your writable directory.
3. Whether or not you're working in a load balanced / web farm environment. If your application is operating in a farmed environment and needs to write files to disk for some reason, you're presented with a whole new problem. How do you keep user generated files on webserver1 in sync with the files generated on webserver2? Doing it via some convoluted syncronization script is painful at best and riddled with race/syncro issues. The best way of implementing this is to create a share on a third server (idealy a cluster with some redundancy) and store the data there. If you're running your worker processes under domain accounts (Security Best Practice), you can even map to the share in the application without having a user/pass anywhere in the code or web.config (makes audit/security people happy). IIS also has the ability to map virtual directories to UNC paths, so this won't impact your ability to make this content web viewable. | App\_Data is, by default, writable but not readable. The server seems to resist any attempt to change this. Thus, it is better to make a completely new folder and change the permissions on it to NOT EXECUTABLE and READABLE and WRITABLE. |
14,655 | Say you have a public ASP.NET (or Classic ASP) application on IIS with a script/page that needs to write or update files in a specific folder that is located within the web publishing folder tree.
1) What is the proper way to set this up?
My main concern is that I want to let the ASP/ASP.NET apps write to a folder, but I don't want regular http users to be able to PUT files into it. | 2009/05/29 | [
"https://serverfault.com/questions/14655",
"https://serverfault.com",
"https://serverfault.com/users/1602/"
] | **The App\_Data Folder**
To improve the security of the data used by your ASP.NET application, a new subfolder named App\_Data has been added for ASP.NET applications. Files stored in the App\_Data folder are not returned in response to direct HTTP requests, which makes the App\_Data folder the recommended location for data stored with your application, including .mdf (SQL Server Express Edition), .mdb (Microsoft Access), or XML files. Note that when using the App\_Data folder to store your application data, the identity of your application has read and write permissions to the App\_Data folder.
[What's new in ASP.NET Data Access](http://msdn.microsoft.com/en-us/library/06t2w7da(v=vs.80).aspx) | App\_Data is, by default, writable but not readable. The server seems to resist any attempt to change this. Thus, it is better to make a completely new folder and change the permissions on it to NOT EXECUTABLE and READABLE and WRITABLE. |
147,023 | How big is the Hogwarts Express train? How big should it be so that all students fit in it?
In the books there is always someone who complains that everything is full but the Trio usually doesn't have to share a compartment with anyone else.
Even in Harry Potter and The Philosophers Stone, Harry and Ron are alone. | 2016/12/11 | [
"https://scifi.stackexchange.com/questions/147023",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/40429/"
] | To the best of my knowledge is never stated directly, but it is implied that the students are sorted into roughly equal numbers in the 4 houses at Hogwarts. There are 7 years and each house has about 10 students per year, or 280 students at the school at any one time, assuming constant class sizes and no dropouts.
If all of the students ride the Hogwarts Express and the cars are standard size, then it has 9 compartments per car, each of which can hold at least 4 students. In this case, the train only needs 8 passenger cars to hold everyone comfortably at 4 passengers per compartment. A normal passenger compartment seats 6, but in the books we almost never see this - it's usually 4 or 5 students per compartment, and sometimes only two.
**From the Film:** The train, at 4 passenger cars, is not big enough to fit the students.
When we see the Hogwarts Express in the movies it only has 3-4 passenger cars, each of which has 8 windows, and presumably 8 passenger compartments per car as a result - far too few for comfortable seating unless it is magically larger inside than outside, such that compartments are possible on both sides of the train, unlike a normal compartment car. Even then, the train would be right at the capacity for students. (4 cars x 16 magical compartments per car x 4 students per compartment = 256 students)
**UPDATE:**
**From the Books:** The train, at 6-7 passenger cars, is just about right for the calculated student population.
Robert Flock, in his answer below, was able to find a reference from the novels to help. Order of the Phoenix, Chapter Ten: “Luna Lovegood” The book describes Harry being goggled at while looking for a seat on the train.
>
> “After he had met this behavior in five consecutive carriages”
>
>
>
He then finds a seat shortly thereafter in the last car on the train. This means that there are six or seven cars. Assuming the same non-magical cars as above, 6 cars with 9 compartments per car each would require an average of just over five students per compartment, or about four and a half if the train had seven passenger cars. This is much more realistic based on the known student population. | The train has undetectable extension charms on the passenger cars, and the majority of sources say there are 3 cars when it runs in the Christmas and Easter, and 5 on the end/beginning if the year (this is including the baggage/prefect car). |
147,023 | How big is the Hogwarts Express train? How big should it be so that all students fit in it?
In the books there is always someone who complains that everything is full but the Trio usually doesn't have to share a compartment with anyone else.
Even in Harry Potter and The Philosophers Stone, Harry and Ron are alone. | 2016/12/11 | [
"https://scifi.stackexchange.com/questions/147023",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/40429/"
] | To the best of my knowledge is never stated directly, but it is implied that the students are sorted into roughly equal numbers in the 4 houses at Hogwarts. There are 7 years and each house has about 10 students per year, or 280 students at the school at any one time, assuming constant class sizes and no dropouts.
If all of the students ride the Hogwarts Express and the cars are standard size, then it has 9 compartments per car, each of which can hold at least 4 students. In this case, the train only needs 8 passenger cars to hold everyone comfortably at 4 passengers per compartment. A normal passenger compartment seats 6, but in the books we almost never see this - it's usually 4 or 5 students per compartment, and sometimes only two.
**From the Film:** The train, at 4 passenger cars, is not big enough to fit the students.
When we see the Hogwarts Express in the movies it only has 3-4 passenger cars, each of which has 8 windows, and presumably 8 passenger compartments per car as a result - far too few for comfortable seating unless it is magically larger inside than outside, such that compartments are possible on both sides of the train, unlike a normal compartment car. Even then, the train would be right at the capacity for students. (4 cars x 16 magical compartments per car x 4 students per compartment = 256 students)
**UPDATE:**
**From the Books:** The train, at 6-7 passenger cars, is just about right for the calculated student population.
Robert Flock, in his answer below, was able to find a reference from the novels to help. Order of the Phoenix, Chapter Ten: “Luna Lovegood” The book describes Harry being goggled at while looking for a seat on the train.
>
> “After he had met this behavior in five consecutive carriages”
>
>
>
He then finds a seat shortly thereafter in the last car on the train. This means that there are six or seven cars. Assuming the same non-magical cars as above, 6 cars with 9 compartments per car each would require an average of just over five students per compartment, or about four and a half if the train had seven passenger cars. This is much more realistic based on the known student population. | *Order of the Phoenix*, Chapter Ten: “Luna Lovegood”. While looking for a seat, having separated from Ron and Hermione who “are supposed to go into the prefect carriage”, Harry is stared at and pointed out by students, it reads:
>
> “After he had met this behavior in five consecutive carriages”
>
>
>
and shortly thereafter Harry meets Neville in “the very last carriage”.
This implies that there would be at least seven carriages: (Prefect carriage, 5 consecutive and last), although the “last carriage” could also be number six. |
147,023 | How big is the Hogwarts Express train? How big should it be so that all students fit in it?
In the books there is always someone who complains that everything is full but the Trio usually doesn't have to share a compartment with anyone else.
Even in Harry Potter and The Philosophers Stone, Harry and Ron are alone. | 2016/12/11 | [
"https://scifi.stackexchange.com/questions/147023",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/40429/"
] | *Order of the Phoenix*, Chapter Ten: “Luna Lovegood”. While looking for a seat, having separated from Ron and Hermione who “are supposed to go into the prefect carriage”, Harry is stared at and pointed out by students, it reads:
>
> “After he had met this behavior in five consecutive carriages”
>
>
>
and shortly thereafter Harry meets Neville in “the very last carriage”.
This implies that there would be at least seven carriages: (Prefect carriage, 5 consecutive and last), although the “last carriage” could also be number six. | The train has undetectable extension charms on the passenger cars, and the majority of sources say there are 3 cars when it runs in the Christmas and Easter, and 5 on the end/beginning if the year (this is including the baggage/prefect car). |
8,534 | We get several questions a day from people trying to run Apache on Windows platforms. Excluding WAMP questions (which are already off-topic), should we allow questions about running Apache on Windows?
Apache is clearly designed to run on \*nix operating systems. While it's possible to run it on Windows, every bone in my body says that it's a really bad idea to do so due to reliability issues, performance issues, and supportability issues. If people want to use Apache, great. Do it on Linux or BSD. If they are stuck using Windows, then bite the bullet and use IIS.
So, what are your thoughts on this? Should these questions be closed due to them not demonstrating "reasonable business information technology management practices"?
---
OK, thanks everyone for your input. We'll leave 'em open (as long as they're not close-worthy for some other reason). | 2015/12/08 | [
"https://meta.serverfault.com/questions/8534",
"https://meta.serverfault.com",
"https://meta.serverfault.com/users/20815/"
] | I'm going to say "leave them open" just because I've supported a couple of vendor products that require Apache on Windows. Those were mainstream packages (things like McAfee ePolicy Orchestrator) that mainstream businesses would use. A fix for a problem with Apache on Windows in a situation like that is not necessarily vendor-specific, and the person asking the question can't just go use IIS instead. | I can't really get behind this there are plenty of Apache httpd systems running on Windows. People should be able to ask questions about them, after all for the majority of issues the answer will be the same and ot OS dependent.
People should though, realise that if their question [relates to an aspect of running Apache httpd on Windows](https://serverfault.com/questions/741651/apache-error-log-showing-error-line-with-no-date) which is OS specific then the chances of it getting answered is significantly lower as there is less mindshare. |
85,261 | Is there a standard screw for tub overflow elbows? Or most popular? I am installing a new tub and looking for a overflow elbow with a screw pattern that will lend itself to a stylish overflow now, and replacement parts for when it gets rusty and grimy down the road.
I've included a picture of a one-screw overflow and two-screw that I have available to me.
[](https://i.stack.imgur.com/WzbY6.jpg) | 2016/02/26 | [
"https://diy.stackexchange.com/questions/85261",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/50433/"
] | Get the 2 hole one; it'll work for those, and single screw overflows almost always come with a bridging plate. | Actually, the only standard is what your bath faucet, knob, overflow & drain (maybe showerhead too, but who buys those they're always the worst clean out the warehouse afterthoughts) ensemble is. The manufacturer of whatever you buy should include its own overflow & drain. If you already have it & it doesn't have these for some reason, then either is fine & just depends on what's available at the store. |
85,261 | Is there a standard screw for tub overflow elbows? Or most popular? I am installing a new tub and looking for a overflow elbow with a screw pattern that will lend itself to a stylish overflow now, and replacement parts for when it gets rusty and grimy down the road.
I've included a picture of a one-screw overflow and two-screw that I have available to me.
[](https://i.stack.imgur.com/WzbY6.jpg) | 2016/02/26 | [
"https://diy.stackexchange.com/questions/85261",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/50433/"
] | I would use whichever fits the hole in the tub better. Note that the 2 hole elbow is a bit larger and may cover better. | Actually, the only standard is what your bath faucet, knob, overflow & drain (maybe showerhead too, but who buys those they're always the worst clean out the warehouse afterthoughts) ensemble is. The manufacturer of whatever you buy should include its own overflow & drain. If you already have it & it doesn't have these for some reason, then either is fine & just depends on what's available at the store. |
85,261 | Is there a standard screw for tub overflow elbows? Or most popular? I am installing a new tub and looking for a overflow elbow with a screw pattern that will lend itself to a stylish overflow now, and replacement parts for when it gets rusty and grimy down the road.
I've included a picture of a one-screw overflow and two-screw that I have available to me.
[](https://i.stack.imgur.com/WzbY6.jpg) | 2016/02/26 | [
"https://diy.stackexchange.com/questions/85261",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/50433/"
] | Get the 2 hole one; it'll work for those, and single screw overflows almost always come with a bridging plate. | I would use whichever fits the hole in the tub better. Note that the 2 hole elbow is a bit larger and may cover better. |
9,494,249 | I want to write a SIP clent in Xcode and want to make call using SIP. Where will I find open source SIP client for Iphone (objective c)?. | 2012/02/29 | [
"https://Stackoverflow.com/questions/9494249",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/1239412/"
] | cancel timer onItemClick, so it wont update data when you have clicked on a item, and if it is needed after item click, start timer again, after call startActivity. | Make use of a java synchronized block |
5,044 | Right now, I'm working on a peach wheat beer. I pitched about 5 days ago now, and the airlock stopped bubbling yesterday. I'm going to do a gravity reading later on today to see if it's finished. My current plan is to rack the beer onto the peaches in secondary, which I've seen recommended in several places. My question is, **how long should I wait between primary fermentation finishing and racking onto the fruit?** I know right now the yeast should be cleaning up after its self in the primary, and if I wasn't going to be adding more sugar (in the form of fruit) in, I'd definitely leave it alone for a while. But, since its about to go ferment again, should I give it time, or can it do clean up once it's done fermenting the peaches? | 2011/09/07 | [
"https://homebrew.stackexchange.com/questions/5044",
"https://homebrew.stackexchange.com",
"https://homebrew.stackexchange.com/users/1561/"
] | It sounds like you already know the answer. You want to wait until the gravity has evened out and off flavors are cleaned up, but not so long that the yeast have all settled. You also want to be sure enough yeast are floating around that fermentation can quickly start again and any bacteria that rode the fruit train will be outnumbered. I usually give it two to three weeks. Follow the advice offered in response to [this question](https://homebrew.stackexchange.com/questions/88/if-when-to-move-to-secondary-fermentation) and you can't go wrong. | I just finished my PeachFuzz Wheat Beer... basically did what you were talking about and it turned out very good. The only problem I had with this mix was with carbonation. After I moved it to a warmer place (about 75deg) it carbed up and is very tastey. I love it! Good luck and I hope it works out for you! |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | No. *Zugzwang* is a chess term (as I suspect you may already know) meaning a state in the game when a player can't make a move without ruining his position: no alternative is acceptable.
You know what *Catch-22* means, as you demonstrate in your previous question. And you asked about *Catch-33* there as well. Maybe you should wait until you are satisfied with an answer there and then compare those ideas to the chess term. | *catch-22* is not a synonymous to *zugzwang*. The first one means a dilemma, or a situation from which there is no escape. *Zugzwang*, while it also pertains to difficult situations, is about being in a tight spot because of a specific rule of chess: you have to make a move at your turn.
PS: I don't know about *catch-33*, but I am sure to be enlightened by the answers to your other question dealing with it. |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | *catch-22* is not a synonymous to *zugzwang*. The first one means a dilemma, or a situation from which there is no escape. *Zugzwang*, while it also pertains to difficult situations, is about being in a tight spot because of a specific rule of chess: you have to make a move at your turn.
PS: I don't know about *catch-33*, but I am sure to be enlightened by the answers to your other question dealing with it. | Yes! Well, sort of. Zugzwang is reasonably synonymous with Catch-22: Both refer to having a dilemma that will not improve, no matter which choice you make. The only difference is that zugzwang implies that you will be in a weaker position after you make a choice. Whereas Catch-22 just implies that whatever you try to change, it will not improve your situation (i.e. it will not necessarily make it worse).
Catch-33 doesn't mean anything. It's just the name of an album. |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | No. *Zugzwang* is a chess term (as I suspect you may already know) meaning a state in the game when a player can't make a move without ruining his position: no alternative is acceptable.
You know what *Catch-22* means, as you demonstrate in your previous question. And you asked about *Catch-33* there as well. Maybe you should wait until you are satisfied with an answer there and then compare those ideas to the chess term. | *Zugzwang*, although it is usually defined otherwise, means that you are already losing and it will become obvious after your next move.
*Catch-22* is about the paradoxes of military life, in particular the impossibility of benefiting from a provision to protect the insane described in the book, and is used for other cases in life where the preconditions for something make it impossible to obtain.
*Catch-33* is simply a play on Catch-22 and means whatever its user wants it to mean; in Meshuggah's case it allowed them to nod towards Heller's book in their album title without attempting to cover it. |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | No. *Zugzwang* is a chess term (as I suspect you may already know) meaning a state in the game when a player can't make a move without ruining his position: no alternative is acceptable.
You know what *Catch-22* means, as you demonstrate in your previous question. And you asked about *Catch-33* there as well. Maybe you should wait until you are satisfied with an answer there and then compare those ideas to the chess term. | While zugzwang is predominantly a chess term, it is also occasionally used metaphorically for real-life situations where whoever makes the next move is left at a disadvantage. This doesn't mean quite the same thing as a Catch-22, although it's similar. |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | No. *Zugzwang* is a chess term (as I suspect you may already know) meaning a state in the game when a player can't make a move without ruining his position: no alternative is acceptable.
You know what *Catch-22* means, as you demonstrate in your previous question. And you asked about *Catch-33* there as well. Maybe you should wait until you are satisfied with an answer there and then compare those ideas to the chess term. | Yes! Well, sort of. Zugzwang is reasonably synonymous with Catch-22: Both refer to having a dilemma that will not improve, no matter which choice you make. The only difference is that zugzwang implies that you will be in a weaker position after you make a choice. Whereas Catch-22 just implies that whatever you try to change, it will not improve your situation (i.e. it will not necessarily make it worse).
Catch-33 doesn't mean anything. It's just the name of an album. |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | *Zugzwang*, although it is usually defined otherwise, means that you are already losing and it will become obvious after your next move.
*Catch-22* is about the paradoxes of military life, in particular the impossibility of benefiting from a provision to protect the insane described in the book, and is used for other cases in life where the preconditions for something make it impossible to obtain.
*Catch-33* is simply a play on Catch-22 and means whatever its user wants it to mean; in Meshuggah's case it allowed them to nod towards Heller's book in their album title without attempting to cover it. | Yes! Well, sort of. Zugzwang is reasonably synonymous with Catch-22: Both refer to having a dilemma that will not improve, no matter which choice you make. The only difference is that zugzwang implies that you will be in a weaker position after you make a choice. Whereas Catch-22 just implies that whatever you try to change, it will not improve your situation (i.e. it will not necessarily make it worse).
Catch-33 doesn't mean anything. It's just the name of an album. |
15,241 | >
> The fundamental principle of gestalt perception is the law of prägnanz (German for pithiness).
>
>
>
In German, all nouns are capitalized. Should the above text be written as is, or with "the law of Prägnanz"? | 2011/03/05 | [
"https://english.stackexchange.com/questions/15241",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/-1/"
] | While zugzwang is predominantly a chess term, it is also occasionally used metaphorically for real-life situations where whoever makes the next move is left at a disadvantage. This doesn't mean quite the same thing as a Catch-22, although it's similar. | Yes! Well, sort of. Zugzwang is reasonably synonymous with Catch-22: Both refer to having a dilemma that will not improve, no matter which choice you make. The only difference is that zugzwang implies that you will be in a weaker position after you make a choice. Whereas Catch-22 just implies that whatever you try to change, it will not improve your situation (i.e. it will not necessarily make it worse).
Catch-33 doesn't mean anything. It's just the name of an album. |
50,735 | I have an existing application that uses AES-256-CBC for encrypting data blocks, and HMAC-SHA-256 on the plaintext for eliminating duplicate data blocks.
For performance reasons, I would like to move to AES-256-CCM and using the resulting authentication tag instead of the SHA-256 .
However, this algorithm is designed to generate a 128 bit tag. This is more prone to hash collisions than HMAC-SHA-256. 128 bits doesn't seem to be sufficiently future proof to ensure collision safety for a system potentially storing enormous numbers of blocks.
Is there a way to extend the tags of AES-256-CCM or AES-256-GCM to have 256 bits strength?
Edit: What I'm try to accomplish is to encrypt a set of objects which are eventually stored in Amazon S3 in a content addressed way, that is, the key of the object should be a hash of the plaintext . People with access to my Amazon S3 bucket should not be able to be able to decrypt the data, nor should the scheme allow checking whether a specific known plaintext exists or not in the bucket. That is why the current scheme is HMAC-SHA256 on the plaintext to choose a key for the object, and then encrypting the object using AES-256-CBC with a unique and unpredictable IV.
AES-256-CBC and HMAC-SHA256 are rather slow, and thus I had the idea to use some form of fast authenticated encryption. | 2017/08/09 | [
"https://crypto.stackexchange.com/questions/50735",
"https://crypto.stackexchange.com",
"https://crypto.stackexchange.com/users/50386/"
] | No, there is no black-box type way of increasing the security strength of the tags of [CCM](https://en.wikipedia.org/wiki/CCM_mode) and [GCM](https://en.wikipedia.org/wiki/Galois/Counter_Mode). Because in this case you would apply a deterministic function which couldn't bring you any increases in security as a collision on the input would still lead to a collision on the output.
For [CCM](https://en.wikipedia.org/wiki/CCM_mode) there is also no non-black box type of way, at least if you want to stick to [AES](https://en.wikipedia.org/wiki/Advanced_Encryption_Standard). This is because [CCM](https://en.wikipedia.org/wiki/CCM_mode) uses [CMAC](https://en.wikipedia.org/wiki/One-key_MAC) internally which is close to [CBC-MAC](https://en.wikipedia.org/wiki/CBC-MAC) which is [CBC](https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#CBC) adapted for authentication. The authentication tag for CMAC is the result of an AES encryption and AES is solely specified for 128-bit blocks (which is the size of the AES in- and output).
[GCM](https://en.wikipedia.org/wiki/Galois/Counter_Mode) is similar in that respect to [CCM](https://en.wikipedia.org/wiki/CCM_mode), in that the output of the polynomial hash function is actually [XOR](https://en.wikipedia.org/wiki/Exclusive_or) encrypted with the output of an AES block. However *if* you pick a longer polynomial for GCM (which will instantly break all implementations you may have) and *if* you maybe make some educated changes to how often the polynomial gets evaluated, you *might* get a stronger tag as the result. However this would most-likely be a GCM look-a-like, but would needs its own (difficult) security analysis and new implementations.
On a final note, the tags of [CCM](https://en.wikipedia.org/wiki/CCM_mode), [GCM](https://en.wikipedia.org/wiki/Galois/Counter_Mode) and [HMAC](https://en.wikipedia.org/wiki/Hash-based_message_authentication_code) are *MACs*. MACs are not neccesarily designed to be good hashes (for a fixed key), because [the threat model](https://crypto.stackexchange.com/a/44210/23623) is different for them. They are designed so that you can't find a tag for a message for which you haven't seen a tag before. They are absolutely allowed to output two different tags for the same message or the same tag for two different messages (because an adversary could maybe have predicted a collision but not for which message pair). | For huge amounts of data it would be better to re-key periodically. You could do something like hash your initial secret with SHA256 every 1GiB of data and re-key AES with new secrets.
If I were designing this from scratch I'd put a large (e.g. 512-bit) random nonce at the start of the large message/stream. Then I'd use part of this nonce to seed a CSPRNG for GCM nonces and then use the rest as a salt when repeatedly hashing AES keys to generate new session keys as you go... or something along those lines.
I wouldn't trust AES-GCM with the same key for more than a few gigs of data personally... and less if you're using smaller auth tags or nonces than the 96-bit/128-bit default. There is a table somewhere of recommended max message sizes for different tag sizes, and nonce size will impact how much data you can safely process with one key. |
109,817 | I'm trying to install Fedora on a really old (1999-2000) PC, even though I have set it to boot the CD/DVD drive first it wont boot from the CD, I know the CD 'im using is bootable, do you think that the CD might be too new or something?
Thanks! | 2010/02/17 | [
"https://superuser.com/questions/109817",
"https://superuser.com",
"https://superuser.com/users/6300/"
] | Prior to about 1999, most computers were designed to boot only from a floppy or hard drive. CD Booting was still relatively new, and generally relied on the "[El Torito](http://en.wikipedia.org/wiki/El_Torito_(CD-ROM_standard))" specification that was embedded into the BIOS, that would search an ISO 9660 record on a CD for a special boot sector and perform some emulation magic to get the darn thing booting. Most modern computers don't require any special emulation and "just work". Based on what you have stated, I am willing to bet you are in the category of troubled hardware. Also, not all bootable discs are created equally - so just because some work, doesn't even remotely imply that all should.
Your best bet is to see if there is some outside chance that a BIOS update is available for that motherboard.
Your next best bet is to custom bake some bootable goodness using [ISOLINUX](http://en.wikipedia.org/wiki/Isolinux) for use on a floppy disk (or even make a bootable CD image) which can get the computer up enough to pull down the rest of the Fedora install over the network.
For what it is worth, I find running something like Feather linux on hardware that old is generally far more productive than a full modern distribution like Fedora or Ubuntu. There is also a lightweight Fedora "spin" called LXDE that may even be a better fit.
<http://lxde.org/> | If the machine is from 1999-2000, I would say the most likely cause is that the optical drive is broken.
I see this as a **VERY** common problem either when the optical drive is heavily used for writing in a relatively short period (1), or if the machine has not been used for several years then you suddenly start using again (2).
In the example above, I typically find that for (1) - it manifests by random read/write errors and/or can read from some media and not others. For (2), usually something mechanical ceases up and the drive either no longer works and/or starts making loud and unusual noises.
Both of these problems are not exclusive to those situations, any error can happen at any time - just in my experience, this is what I see a lot of.
I hope this helps - if it doesn't, in comments, can you write if the machine can read other bootable disks, or standard disks from within any operating system it runs?
Also, if you have a spare known working optical drive, it may be easier if you just quickly swap them around and test. |
109,817 | I'm trying to install Fedora on a really old (1999-2000) PC, even though I have set it to boot the CD/DVD drive first it wont boot from the CD, I know the CD 'im using is bootable, do you think that the CD might be too new or something?
Thanks! | 2010/02/17 | [
"https://superuser.com/questions/109817",
"https://superuser.com",
"https://superuser.com/users/6300/"
] | I've experienced this. The BIOS may be too old and not support booting fron a DVD device. I could not find a BIOS upgrade so I have to temporarily attach an old CD drive I had laying around. | If the machine is from 1999-2000, I would say the most likely cause is that the optical drive is broken.
I see this as a **VERY** common problem either when the optical drive is heavily used for writing in a relatively short period (1), or if the machine has not been used for several years then you suddenly start using again (2).
In the example above, I typically find that for (1) - it manifests by random read/write errors and/or can read from some media and not others. For (2), usually something mechanical ceases up and the drive either no longer works and/or starts making loud and unusual noises.
Both of these problems are not exclusive to those situations, any error can happen at any time - just in my experience, this is what I see a lot of.
I hope this helps - if it doesn't, in comments, can you write if the machine can read other bootable disks, or standard disks from within any operating system it runs?
Also, if you have a spare known working optical drive, it may be easier if you just quickly swap them around and test. |
109,817 | I'm trying to install Fedora on a really old (1999-2000) PC, even though I have set it to boot the CD/DVD drive first it wont boot from the CD, I know the CD 'im using is bootable, do you think that the CD might be too new or something?
Thanks! | 2010/02/17 | [
"https://superuser.com/questions/109817",
"https://superuser.com",
"https://superuser.com/users/6300/"
] | Prior to about 1999, most computers were designed to boot only from a floppy or hard drive. CD Booting was still relatively new, and generally relied on the "[El Torito](http://en.wikipedia.org/wiki/El_Torito_(CD-ROM_standard))" specification that was embedded into the BIOS, that would search an ISO 9660 record on a CD for a special boot sector and perform some emulation magic to get the darn thing booting. Most modern computers don't require any special emulation and "just work". Based on what you have stated, I am willing to bet you are in the category of troubled hardware. Also, not all bootable discs are created equally - so just because some work, doesn't even remotely imply that all should.
Your best bet is to see if there is some outside chance that a BIOS update is available for that motherboard.
Your next best bet is to custom bake some bootable goodness using [ISOLINUX](http://en.wikipedia.org/wiki/Isolinux) for use on a floppy disk (or even make a bootable CD image) which can get the computer up enough to pull down the rest of the Fedora install over the network.
For what it is worth, I find running something like Feather linux on hardware that old is generally far more productive than a full modern distribution like Fedora or Ubuntu. There is also a lightweight Fedora "spin" called LXDE that may even be a better fit.
<http://lxde.org/> | I've experienced this. The BIOS may be too old and not support booting fron a DVD device. I could not find a BIOS upgrade so I have to temporarily attach an old CD drive I had laying around. |
109,817 | I'm trying to install Fedora on a really old (1999-2000) PC, even though I have set it to boot the CD/DVD drive first it wont boot from the CD, I know the CD 'im using is bootable, do you think that the CD might be too new or something?
Thanks! | 2010/02/17 | [
"https://superuser.com/questions/109817",
"https://superuser.com",
"https://superuser.com/users/6300/"
] | Prior to about 1999, most computers were designed to boot only from a floppy or hard drive. CD Booting was still relatively new, and generally relied on the "[El Torito](http://en.wikipedia.org/wiki/El_Torito_(CD-ROM_standard))" specification that was embedded into the BIOS, that would search an ISO 9660 record on a CD for a special boot sector and perform some emulation magic to get the darn thing booting. Most modern computers don't require any special emulation and "just work". Based on what you have stated, I am willing to bet you are in the category of troubled hardware. Also, not all bootable discs are created equally - so just because some work, doesn't even remotely imply that all should.
Your best bet is to see if there is some outside chance that a BIOS update is available for that motherboard.
Your next best bet is to custom bake some bootable goodness using [ISOLINUX](http://en.wikipedia.org/wiki/Isolinux) for use on a floppy disk (or even make a bootable CD image) which can get the computer up enough to pull down the rest of the Fedora install over the network.
For what it is worth, I find running something like Feather linux on hardware that old is generally far more productive than a full modern distribution like Fedora or Ubuntu. There is also a lightweight Fedora "spin" called LXDE that may even be a better fit.
<http://lxde.org/> | In my case it started to boot from the CDROM after I had disabled Quick boot in BIOS |
109,817 | I'm trying to install Fedora on a really old (1999-2000) PC, even though I have set it to boot the CD/DVD drive first it wont boot from the CD, I know the CD 'im using is bootable, do you think that the CD might be too new or something?
Thanks! | 2010/02/17 | [
"https://superuser.com/questions/109817",
"https://superuser.com",
"https://superuser.com/users/6300/"
] | I've experienced this. The BIOS may be too old and not support booting fron a DVD device. I could not find a BIOS upgrade so I have to temporarily attach an old CD drive I had laying around. | In my case it started to boot from the CDROM after I had disabled Quick boot in BIOS |
11,827,979 | I currently have a web service that does as follows:
- User inputs image
- Web service launches a C program using OpenCV
- The program loads training data
- The program detects and recognises certain objects
- The program records these detections and recognitions in a MySQL database
- If the program has detected and recognised objects, it adds it to the training data
This program can take up to 1 minute to run per image. How could I structure Amazon Web Services to do this efficiently? | 2012/08/06 | [
"https://Stackoverflow.com/questions/11827979",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/293895/"
] | Coincidentally, AWS released a [detailed tutorial](http://aws.amazon.com/articles/1602) about processing images, using EC2, S3, SimpleDB, and SQS. It should get you most of the way there. | U can go for **step function** in aws there u will see the process with one f |
948,187 | I'm about to setup a backup using an LTO-4 Drive. I know that drives are meant to be compatible to any tape within the past 3 generations (so I should be able to read an LTO-4 tape using an LTO-4, 5 or 6 drive).
I wonder if this also applies to **hardware compression** and **hardware encryption**?
Is it safe in practice to rely on the ability of any LTO-4/5/6 drive to read my backup tapes? | 2019/01/09 | [
"https://serverfault.com/questions/948187",
"https://serverfault.com",
"https://serverfault.com/users/151/"
] | Both compression and encryption are parts of the LTO standard. This means that a compressed and encrypted LTO-4 tape should be read by a LTO-6 drive.
That said, as the hardware encryption key can be managed by the backup system itself, I think that occasional compatibility problem can arise, at least in theory. On the other side, for compression I don't expect anything to go wrong. | The answer that the LTO consortium want you to read is Yes, but unfortunately it isn't that simple.
Both major OEMs (IBM and HP) do follow published standards [*IEEE 1619.1*](https://standards.ieee.org/standard/1619_1-2018.html) ([see also](https://darkimmortal.com/wp-content/uploads/2020/02/using-gcm-aes-for-tape-encryption.pdf)) (encryption) and *[ISO/IEC 22091:2002](https://standards.iso.org/ittf/PubliclyAvailableStandards/c036090_ISO_IEC_22091_2002(E).zip)* / *[ECMA-321](https://www.ecma-international.org/publications/files/ECMA-ST/ECMA-321.pdf)* (compression). However there are some slight differences in areas that are not covered by the standard, for example: IV generation differs between drives, IBM disregards raw data protection flags, and IBM has a different (and better) SLDC compression algorithm. You can find more detail here: <https://darkimmortal.com/the-secrets-of-lto-tape/>
Returning to the spirit of the original question, one key issue I have found is that **IBM LTO-4 drives cannot read *encrypted* LTO-4 tapes written by HP LTO-4 drives** (drive immediately crashes on read and has to be restarted). I've tried enough combinations of firmwares, settings, tapes and data that I am as certain as one can be with 2 drives that this is a wider issue. I doubt this issue exists in later generations or it would be more widely reported, but it highlights the fact that the LTO standard isn't as bulletproof as the marketing would suggest. I have written a program to workaround this issue in software: <https://github.com/lukefor/ltoex>
Additionally, IBM SLDC compression does not appear to follow spec. Although I have not seen any issues with HP drives' ability to read this data, I was not able to decompress it successfully in software by following the standard. |
11,059 | My Japan resident card is good until 2021, but my passport will expire in less than 6 months. I need to go on a business trip outside of Japan very soon and may not have enough time to renew my passport.
The trip itself only lasts about 1 week so my passport will still be valid when I come back, but with less than 6 months of validity, will I be able to enter Japan?
**Update**: the consensus is while I won't have trouble entering Japan with my soon to expired passport, it is possible that airline will deny me boarding. Because of that, I decided to play it safe and paid some extra money to have my passport renewed quickly. | 2017/05/31 | [
"https://expatriates.stackexchange.com/questions/11059",
"https://expatriates.stackexchange.com",
"https://expatriates.stackexchange.com/users/8758/"
] | There is no 6 month validity requirement listed in the official guidelines.
[Requirements for foreigners entering Japan](http://www.immi-moj.go.jp/english/tetuduki/kanri/youken.html):
>
> Foreigners must have a valid passport to enter Japanese territory.
>
>
>
And [Landing Procedures for foreign nationals](http://www.immi-moj.go.jp/english/tetuduki/kanri/zyouriku.html):
>
> A foreign national must satisfy the following conditions for landing
> in Japan (Article 7, Paragraph 1 of the Immigration Control Act)
> before he is permitted to enter the country with the status of
> residence and period of stay authorized.
>
>
> 1. The foreign national must hold a valid passport with a valid visa issued by a Japanese counsular officer;
>
>
> | For Japanese immigration passport should be valid on reentry day. Problem can be with airline if they use inconsistent information. |
344,822 | I was playing Super Smash Bros Brawl (after the release of Super Smash Bros Ultimate) and I played a my main man Yoshi and I picked up an item. I saw another item better than the one I had. However couldn’t drop my current item so I couldn’t pick up the new one.
How do I drop items in Super Smash Bros Brawl? | 2019/01/10 | [
"https://gaming.stackexchange.com/questions/344822",
"https://gaming.stackexchange.com",
"https://gaming.stackexchange.com/users/225113/"
] | There are several ways to drop items:
1) Dropping - This lets you just drop the item where you are and is much faster than throwing it. Just grab while not pressing any direction and your character will drop the item where you are.
2) Throwing - Press a direction on the left stick like you are running and press grab; your character will throw the item in that direction.
3) Getting hit - If you get hit enough, you will eventually drop whatever item you are holding. I believe it is dependent on your damage/the attack's damage/knockback but there is some randomness involved. | Literally just press the grab button. If you want to throw it (which can be used to fight enemies) then move the left stick (or hold a direction on the D-Pad) in the direction you want to throw it in as you press the attack button. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | **Primary Advantage: Psychological Control**
The primary advantage for manipulating toddlers would be **psychological**, not the physical training. By stunting certain emotional development patterns, it would be possible to make hyper-violent (and possibly hyper-loyal) soldiers. Taking over the psychological development of toddlers would also *prevent the child from having any memories* of life with parents, siblings, friends, or a non-military world. None of that pesky individuality to get in the way. The child may not even believe they are human (either god, slave, angel, half-human, alien, etc) - they may believe they are grown, produced, or "manifested" through a non-birth process. Heck, they may not even know about sex or reproduction! Absolute control over their earliest memories equals absolute control over their basic view of the universe.
>
> would this process result in improved soldiers?
>
>
>
Depends on what you mean by "improved" - that's not immediately obvious. If "super loyal, willing to die, and *very* good at being violent" equates to "improved", then yes. But with every pro is a con. It's difficult to stunt someone's growth and then have them be creative thinkers. You need at least one guy to be able to think calmly and strategically, which becomes both a strength (not very much insubordination) and a major weakness (that guy becomes a single point of failure for the entire military structure). I'm sure there are many other cons, but that would depend on the specifics of your story. | cegfault pointed out the main draw of this method, but I'd like to complete with drawbacks:
While I'm not knowledgeable in epigenetic1, a lot of things during your growth will affect the final result, and not only on a genetic level.
While exercising is connected to the release of hormones linked to growth and muscle development, over-exercising has also been proven to be harmful to a child development. Too much effort and/or muscle mass will grind down the growth cartilage.
Starving and depriving of sleep someone will also affect their physical development. You will probably achieve murderous sociopaths given the proper training, but you must expect mental and physical setbacks if you overdo it, especially at a young age.
So a too harsh training from a young age seems suboptimal, as you will eventually produce a bunch of degenerates hyper violent short-sized, short-focused "murder hobos".
1: Only learned about that recently, it's the science focused on the changes in genes expression during life, as far as I understood. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | I cant find the article I read anymore so this will have to do: <https://scholar.google.nl/scholar?hl=nl&as_sdt=0%2C5&q=olympic+training+toddlers&btnG=#d=gs_qabs&u=%23p%3D31F1lBUcOosJ>
What I read was an article which trained children extremely young to see the effects. They trained the children in ice skating using play and rewards (rather than shocks which would reduce the effects of training). This allowed the children to be extremely good at ice skating. Not olympic material (yet) but they surpassed many semi-professionals. The drawback was that other skills immediately suffered, such as development of communication, social skills and learning what the world was ("this is a bench, that is a shirt"). Once they stopped the program most of these skills saw a massive drop, while "normal" skills for that age rapidly started catching up.
A more well-suited way to teach would be to encourage playsessions that learn them the basics, rather than hyperfocus on military aspects which will most certainly mean that other 'less important' skills will lack.
As for essentially abusing your children to "make them pain resistant", you might as well set up gladiatorial combat to the death as that will be close to what your army would be doing to itself. <https://www.secasa.com.au/pages/child-physical-abuse-understanding-and-responding/effects-of-child-physical-abuse/>
These children would become insubordinate, lack the skills to work together as a group, have issues with anger management, would be violent (not a good thing as they would be violent against fellow soldiers and officers just as easily), have problems with getting new children in your army and many other psychological problems.
A better way is to encourage a proper response to pain. Lets say you add tree climbing to the programs and make small contests for the children to climb towards a goal (not necessarily the fastest as that only encourages the best climbers to play). Climbing causes small wounds but when play is fun those arent as important and the child will learn what pains it can ignore and when pains are serious enough to keep an eye on, IE "I fell and broke a finger" is a good moment for a child to react and seek help to learn how to treat it. Additional advantage of such playtypes would be a stronger immune system. Tree climbing is just one example, and the idea would be to have a variety of playtypes that encourage not just physical exercise but also having to think and plan through a situation. Say having a treasure hunt for some candy but having to overcome some obstacles to get there. Depending on the age the amount of support would change. Toddlers would be guided by adults, this would strengthen their belief in listening to others and cooperation while the adults can present them with bite-sized problems tailored to the current skill of the children. Older children would get less supervision but more responsibility. A great way would be to have older children guide younger one's while an adult supervises the entire group to steer them. It teaches responsibility, guidance and teaches the older children both when to trust in someone's abilities once they give an order and when they need guidance. It also teaches them that guiding is a far better option than ordering and expecting results every time. | **Primary Advantage: Psychological Control**
The primary advantage for manipulating toddlers would be **psychological**, not the physical training. By stunting certain emotional development patterns, it would be possible to make hyper-violent (and possibly hyper-loyal) soldiers. Taking over the psychological development of toddlers would also *prevent the child from having any memories* of life with parents, siblings, friends, or a non-military world. None of that pesky individuality to get in the way. The child may not even believe they are human (either god, slave, angel, half-human, alien, etc) - they may believe they are grown, produced, or "manifested" through a non-birth process. Heck, they may not even know about sex or reproduction! Absolute control over their earliest memories equals absolute control over their basic view of the universe.
>
> would this process result in improved soldiers?
>
>
>
Depends on what you mean by "improved" - that's not immediately obvious. If "super loyal, willing to die, and *very* good at being violent" equates to "improved", then yes. But with every pro is a con. It's difficult to stunt someone's growth and then have them be creative thinkers. You need at least one guy to be able to think calmly and strategically, which becomes both a strength (not very much insubordination) and a major weakness (that guy becomes a single point of failure for the entire military structure). I'm sure there are many other cons, but that would depend on the specifics of your story. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | **Primary Advantage: Psychological Control**
The primary advantage for manipulating toddlers would be **psychological**, not the physical training. By stunting certain emotional development patterns, it would be possible to make hyper-violent (and possibly hyper-loyal) soldiers. Taking over the psychological development of toddlers would also *prevent the child from having any memories* of life with parents, siblings, friends, or a non-military world. None of that pesky individuality to get in the way. The child may not even believe they are human (either god, slave, angel, half-human, alien, etc) - they may believe they are grown, produced, or "manifested" through a non-birth process. Heck, they may not even know about sex or reproduction! Absolute control over their earliest memories equals absolute control over their basic view of the universe.
>
> would this process result in improved soldiers?
>
>
>
Depends on what you mean by "improved" - that's not immediately obvious. If "super loyal, willing to die, and *very* good at being violent" equates to "improved", then yes. But with every pro is a con. It's difficult to stunt someone's growth and then have them be creative thinkers. You need at least one guy to be able to think calmly and strategically, which becomes both a strength (not very much insubordination) and a major weakness (that guy becomes a single point of failure for the entire military structure). I'm sure there are many other cons, but that would depend on the specifics of your story. | While a few answers explain the downsides of your plan to militarize their early training I want to explain a path you could take. Don't train your children through sheer adversity, train them optimally. There is a lot of research out there how to raise a proper adult.
Care for them, exercise them but not to much. Give them proper nutrition to maximize potential physical limits. Raise them as well adjusted adults that can improvise and are stress resistant. You don't want a dumb grunt, you want an elite killing machine. Given the amount of resources you put into them you're going for special forces of some kind.
Now the point you start giving this your own spin is in the loyalty department. For a soldier loyalty is key, it will make them accept orders without hesitation, it will allow them to push through their limits. Donb't be feared, be loved.
Research into animals has shown loyalty is best achieved by mixing love and pain. Sheer pain and torture will turn the subject away, they simply fear their caretakers and shun contact. Just love make s them loyal but only so much. Mixing them is the sweet spot. Experiencing a good deal of love make them familiar with it. But alternating it with harsh punishment creates a fear. A fear they'll fight to prevent to become reality.
Be kind to them till they misbehave. Punish laziness but reward giving it all. With a loyal subject you can train them to be anything. Combine this with shaping their moral frame of reference and you can get incredible control over your soldiers. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | **Primary Advantage: Psychological Control**
The primary advantage for manipulating toddlers would be **psychological**, not the physical training. By stunting certain emotional development patterns, it would be possible to make hyper-violent (and possibly hyper-loyal) soldiers. Taking over the psychological development of toddlers would also *prevent the child from having any memories* of life with parents, siblings, friends, or a non-military world. None of that pesky individuality to get in the way. The child may not even believe they are human (either god, slave, angel, half-human, alien, etc) - they may believe they are grown, produced, or "manifested" through a non-birth process. Heck, they may not even know about sex or reproduction! Absolute control over their earliest memories equals absolute control over their basic view of the universe.
>
> would this process result in improved soldiers?
>
>
>
Depends on what you mean by "improved" - that's not immediately obvious. If "super loyal, willing to die, and *very* good at being violent" equates to "improved", then yes. But with every pro is a con. It's difficult to stunt someone's growth and then have them be creative thinkers. You need at least one guy to be able to think calmly and strategically, which becomes both a strength (not very much insubordination) and a major weakness (that guy becomes a single point of failure for the entire military structure). I'm sure there are many other cons, but that would depend on the specifics of your story. | There is not much historical evidence for training soldiers or warriors when they are toddlers.
A toddler is defined as a child just learning to walk, or as a child age 12 to 36 months.
As far as I can tell the youngest boys to ever be officially enlisted in professional armed forces were aged five at the time, and that was very rare, and also much older than a toddler.
As for a warrior class, the Spartans began training boys to be warriors at age seven.
As far as I can tell, the youngest soldiers and sailors to successfully carry out military duties would have been not much younger than ten - nine or eight being the youngest I can think of and very rare.
Similarly, the youngest military & naval officers on active duty would have been not much younger than ten, and that would have been very unusual.
Therefore, military training of toddlers would not begin to pay off with reasonably competent and capable soldiers for five, ten, or maybe even fifteen years. The average length of military training has varied a lot, from weeks to years, but even five years training before active duty for the average soldier in an army would be unusually long and expensive.
Therefore most societies would not have universal training of children as soldiers beginning as toddlers, considering it a waste of time and money, and your society needs a special reason to begin that practice. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | I cant find the article I read anymore so this will have to do: <https://scholar.google.nl/scholar?hl=nl&as_sdt=0%2C5&q=olympic+training+toddlers&btnG=#d=gs_qabs&u=%23p%3D31F1lBUcOosJ>
What I read was an article which trained children extremely young to see the effects. They trained the children in ice skating using play and rewards (rather than shocks which would reduce the effects of training). This allowed the children to be extremely good at ice skating. Not olympic material (yet) but they surpassed many semi-professionals. The drawback was that other skills immediately suffered, such as development of communication, social skills and learning what the world was ("this is a bench, that is a shirt"). Once they stopped the program most of these skills saw a massive drop, while "normal" skills for that age rapidly started catching up.
A more well-suited way to teach would be to encourage playsessions that learn them the basics, rather than hyperfocus on military aspects which will most certainly mean that other 'less important' skills will lack.
As for essentially abusing your children to "make them pain resistant", you might as well set up gladiatorial combat to the death as that will be close to what your army would be doing to itself. <https://www.secasa.com.au/pages/child-physical-abuse-understanding-and-responding/effects-of-child-physical-abuse/>
These children would become insubordinate, lack the skills to work together as a group, have issues with anger management, would be violent (not a good thing as they would be violent against fellow soldiers and officers just as easily), have problems with getting new children in your army and many other psychological problems.
A better way is to encourage a proper response to pain. Lets say you add tree climbing to the programs and make small contests for the children to climb towards a goal (not necessarily the fastest as that only encourages the best climbers to play). Climbing causes small wounds but when play is fun those arent as important and the child will learn what pains it can ignore and when pains are serious enough to keep an eye on, IE "I fell and broke a finger" is a good moment for a child to react and seek help to learn how to treat it. Additional advantage of such playtypes would be a stronger immune system. Tree climbing is just one example, and the idea would be to have a variety of playtypes that encourage not just physical exercise but also having to think and plan through a situation. Say having a treasure hunt for some candy but having to overcome some obstacles to get there. Depending on the age the amount of support would change. Toddlers would be guided by adults, this would strengthen their belief in listening to others and cooperation while the adults can present them with bite-sized problems tailored to the current skill of the children. Older children would get less supervision but more responsibility. A great way would be to have older children guide younger one's while an adult supervises the entire group to steer them. It teaches responsibility, guidance and teaches the older children both when to trust in someone's abilities once they give an order and when they need guidance. It also teaches them that guiding is a far better option than ordering and expecting results every time. | cegfault pointed out the main draw of this method, but I'd like to complete with drawbacks:
While I'm not knowledgeable in epigenetic1, a lot of things during your growth will affect the final result, and not only on a genetic level.
While exercising is connected to the release of hormones linked to growth and muscle development, over-exercising has also been proven to be harmful to a child development. Too much effort and/or muscle mass will grind down the growth cartilage.
Starving and depriving of sleep someone will also affect their physical development. You will probably achieve murderous sociopaths given the proper training, but you must expect mental and physical setbacks if you overdo it, especially at a young age.
So a too harsh training from a young age seems suboptimal, as you will eventually produce a bunch of degenerates hyper violent short-sized, short-focused "murder hobos".
1: Only learned about that recently, it's the science focused on the changes in genes expression during life, as far as I understood. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | cegfault pointed out the main draw of this method, but I'd like to complete with drawbacks:
While I'm not knowledgeable in epigenetic1, a lot of things during your growth will affect the final result, and not only on a genetic level.
While exercising is connected to the release of hormones linked to growth and muscle development, over-exercising has also been proven to be harmful to a child development. Too much effort and/or muscle mass will grind down the growth cartilage.
Starving and depriving of sleep someone will also affect their physical development. You will probably achieve murderous sociopaths given the proper training, but you must expect mental and physical setbacks if you overdo it, especially at a young age.
So a too harsh training from a young age seems suboptimal, as you will eventually produce a bunch of degenerates hyper violent short-sized, short-focused "murder hobos".
1: Only learned about that recently, it's the science focused on the changes in genes expression during life, as far as I understood. | There is not much historical evidence for training soldiers or warriors when they are toddlers.
A toddler is defined as a child just learning to walk, or as a child age 12 to 36 months.
As far as I can tell the youngest boys to ever be officially enlisted in professional armed forces were aged five at the time, and that was very rare, and also much older than a toddler.
As for a warrior class, the Spartans began training boys to be warriors at age seven.
As far as I can tell, the youngest soldiers and sailors to successfully carry out military duties would have been not much younger than ten - nine or eight being the youngest I can think of and very rare.
Similarly, the youngest military & naval officers on active duty would have been not much younger than ten, and that would have been very unusual.
Therefore, military training of toddlers would not begin to pay off with reasonably competent and capable soldiers for five, ten, or maybe even fifteen years. The average length of military training has varied a lot, from weeks to years, but even five years training before active duty for the average soldier in an army would be unusually long and expensive.
Therefore most societies would not have universal training of children as soldiers beginning as toddlers, considering it a waste of time and money, and your society needs a special reason to begin that practice. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | I cant find the article I read anymore so this will have to do: <https://scholar.google.nl/scholar?hl=nl&as_sdt=0%2C5&q=olympic+training+toddlers&btnG=#d=gs_qabs&u=%23p%3D31F1lBUcOosJ>
What I read was an article which trained children extremely young to see the effects. They trained the children in ice skating using play and rewards (rather than shocks which would reduce the effects of training). This allowed the children to be extremely good at ice skating. Not olympic material (yet) but they surpassed many semi-professionals. The drawback was that other skills immediately suffered, such as development of communication, social skills and learning what the world was ("this is a bench, that is a shirt"). Once they stopped the program most of these skills saw a massive drop, while "normal" skills for that age rapidly started catching up.
A more well-suited way to teach would be to encourage playsessions that learn them the basics, rather than hyperfocus on military aspects which will most certainly mean that other 'less important' skills will lack.
As for essentially abusing your children to "make them pain resistant", you might as well set up gladiatorial combat to the death as that will be close to what your army would be doing to itself. <https://www.secasa.com.au/pages/child-physical-abuse-understanding-and-responding/effects-of-child-physical-abuse/>
These children would become insubordinate, lack the skills to work together as a group, have issues with anger management, would be violent (not a good thing as they would be violent against fellow soldiers and officers just as easily), have problems with getting new children in your army and many other psychological problems.
A better way is to encourage a proper response to pain. Lets say you add tree climbing to the programs and make small contests for the children to climb towards a goal (not necessarily the fastest as that only encourages the best climbers to play). Climbing causes small wounds but when play is fun those arent as important and the child will learn what pains it can ignore and when pains are serious enough to keep an eye on, IE "I fell and broke a finger" is a good moment for a child to react and seek help to learn how to treat it. Additional advantage of such playtypes would be a stronger immune system. Tree climbing is just one example, and the idea would be to have a variety of playtypes that encourage not just physical exercise but also having to think and plan through a situation. Say having a treasure hunt for some candy but having to overcome some obstacles to get there. Depending on the age the amount of support would change. Toddlers would be guided by adults, this would strengthen their belief in listening to others and cooperation while the adults can present them with bite-sized problems tailored to the current skill of the children. Older children would get less supervision but more responsibility. A great way would be to have older children guide younger one's while an adult supervises the entire group to steer them. It teaches responsibility, guidance and teaches the older children both when to trust in someone's abilities once they give an order and when they need guidance. It also teaches them that guiding is a far better option than ordering and expecting results every time. | While a few answers explain the downsides of your plan to militarize their early training I want to explain a path you could take. Don't train your children through sheer adversity, train them optimally. There is a lot of research out there how to raise a proper adult.
Care for them, exercise them but not to much. Give them proper nutrition to maximize potential physical limits. Raise them as well adjusted adults that can improvise and are stress resistant. You don't want a dumb grunt, you want an elite killing machine. Given the amount of resources you put into them you're going for special forces of some kind.
Now the point you start giving this your own spin is in the loyalty department. For a soldier loyalty is key, it will make them accept orders without hesitation, it will allow them to push through their limits. Donb't be feared, be loved.
Research into animals has shown loyalty is best achieved by mixing love and pain. Sheer pain and torture will turn the subject away, they simply fear their caretakers and shun contact. Just love make s them loyal but only so much. Mixing them is the sweet spot. Experiencing a good deal of love make them familiar with it. But alternating it with harsh punishment creates a fear. A fear they'll fight to prevent to become reality.
Be kind to them till they misbehave. Punish laziness but reward giving it all. With a loyal subject you can train them to be anything. Combine this with shaping their moral frame of reference and you can get incredible control over your soldiers. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | I cant find the article I read anymore so this will have to do: <https://scholar.google.nl/scholar?hl=nl&as_sdt=0%2C5&q=olympic+training+toddlers&btnG=#d=gs_qabs&u=%23p%3D31F1lBUcOosJ>
What I read was an article which trained children extremely young to see the effects. They trained the children in ice skating using play and rewards (rather than shocks which would reduce the effects of training). This allowed the children to be extremely good at ice skating. Not olympic material (yet) but they surpassed many semi-professionals. The drawback was that other skills immediately suffered, such as development of communication, social skills and learning what the world was ("this is a bench, that is a shirt"). Once they stopped the program most of these skills saw a massive drop, while "normal" skills for that age rapidly started catching up.
A more well-suited way to teach would be to encourage playsessions that learn them the basics, rather than hyperfocus on military aspects which will most certainly mean that other 'less important' skills will lack.
As for essentially abusing your children to "make them pain resistant", you might as well set up gladiatorial combat to the death as that will be close to what your army would be doing to itself. <https://www.secasa.com.au/pages/child-physical-abuse-understanding-and-responding/effects-of-child-physical-abuse/>
These children would become insubordinate, lack the skills to work together as a group, have issues with anger management, would be violent (not a good thing as they would be violent against fellow soldiers and officers just as easily), have problems with getting new children in your army and many other psychological problems.
A better way is to encourage a proper response to pain. Lets say you add tree climbing to the programs and make small contests for the children to climb towards a goal (not necessarily the fastest as that only encourages the best climbers to play). Climbing causes small wounds but when play is fun those arent as important and the child will learn what pains it can ignore and when pains are serious enough to keep an eye on, IE "I fell and broke a finger" is a good moment for a child to react and seek help to learn how to treat it. Additional advantage of such playtypes would be a stronger immune system. Tree climbing is just one example, and the idea would be to have a variety of playtypes that encourage not just physical exercise but also having to think and plan through a situation. Say having a treasure hunt for some candy but having to overcome some obstacles to get there. Depending on the age the amount of support would change. Toddlers would be guided by adults, this would strengthen their belief in listening to others and cooperation while the adults can present them with bite-sized problems tailored to the current skill of the children. Older children would get less supervision but more responsibility. A great way would be to have older children guide younger one's while an adult supervises the entire group to steer them. It teaches responsibility, guidance and teaches the older children both when to trust in someone's abilities once they give an order and when they need guidance. It also teaches them that guiding is a far better option than ordering and expecting results every time. | There is not much historical evidence for training soldiers or warriors when they are toddlers.
A toddler is defined as a child just learning to walk, or as a child age 12 to 36 months.
As far as I can tell the youngest boys to ever be officially enlisted in professional armed forces were aged five at the time, and that was very rare, and also much older than a toddler.
As for a warrior class, the Spartans began training boys to be warriors at age seven.
As far as I can tell, the youngest soldiers and sailors to successfully carry out military duties would have been not much younger than ten - nine or eight being the youngest I can think of and very rare.
Similarly, the youngest military & naval officers on active duty would have been not much younger than ten, and that would have been very unusual.
Therefore, military training of toddlers would not begin to pay off with reasonably competent and capable soldiers for five, ten, or maybe even fifteen years. The average length of military training has varied a lot, from weeks to years, but even five years training before active duty for the average soldier in an army would be unusually long and expensive.
Therefore most societies would not have universal training of children as soldiers beginning as toddlers, considering it a waste of time and money, and your society needs a special reason to begin that practice. |
140,705 | I saw [this](https://worldbuilding.stackexchange.com/questions/78974/military-or-assassin-training-from-early-childhood) question, but mine is slightly different.
Could a hyper militaristic society get better soldiers by training all children from when they are toddlers?
They would be put in state-run training centers, where they would be rigorously instructed in combat skills. While they would probably not be strong enough to hold and fire adult sized assault rifles, they could still be taught how to dig defensive fighting positions and reinforce them with wood/sandbags/scrap metal, clean and maintain weapons, perform first aid, to practice proper gun safety, to swim and climb, the basics of hand to hand combat, map reading and navigation, vehicle maintenance, etc.
They could start with simpler tasks first, then move on to more complex ones later. The children could also be taken on long marches through harsh terrain while carrying heavy weights to toughen them up, and made to play "anything goes" capture the flag to increase their aggression.
* Electric shocks would be used to make them follow orders and to become very disciplined and pain resistant. You would also be able to control their food, water, and sleep schedules, so that you can teach them how to operate while starved, dehydrated, and with little sleep.
* You would also be able to indoctrinate them about the glory of the state and to exterminate its enemies without mercy, because they are disgusting subhuman vermin.
Obviously, these children would become emotionally-stunted borderline-psychopaths, but would this process result in improved soldiers? | 2019/03/04 | [
"https://worldbuilding.stackexchange.com/questions/140705",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43560/"
] | While a few answers explain the downsides of your plan to militarize their early training I want to explain a path you could take. Don't train your children through sheer adversity, train them optimally. There is a lot of research out there how to raise a proper adult.
Care for them, exercise them but not to much. Give them proper nutrition to maximize potential physical limits. Raise them as well adjusted adults that can improvise and are stress resistant. You don't want a dumb grunt, you want an elite killing machine. Given the amount of resources you put into them you're going for special forces of some kind.
Now the point you start giving this your own spin is in the loyalty department. For a soldier loyalty is key, it will make them accept orders without hesitation, it will allow them to push through their limits. Donb't be feared, be loved.
Research into animals has shown loyalty is best achieved by mixing love and pain. Sheer pain and torture will turn the subject away, they simply fear their caretakers and shun contact. Just love make s them loyal but only so much. Mixing them is the sweet spot. Experiencing a good deal of love make them familiar with it. But alternating it with harsh punishment creates a fear. A fear they'll fight to prevent to become reality.
Be kind to them till they misbehave. Punish laziness but reward giving it all. With a loyal subject you can train them to be anything. Combine this with shaping their moral frame of reference and you can get incredible control over your soldiers. | There is not much historical evidence for training soldiers or warriors when they are toddlers.
A toddler is defined as a child just learning to walk, or as a child age 12 to 36 months.
As far as I can tell the youngest boys to ever be officially enlisted in professional armed forces were aged five at the time, and that was very rare, and also much older than a toddler.
As for a warrior class, the Spartans began training boys to be warriors at age seven.
As far as I can tell, the youngest soldiers and sailors to successfully carry out military duties would have been not much younger than ten - nine or eight being the youngest I can think of and very rare.
Similarly, the youngest military & naval officers on active duty would have been not much younger than ten, and that would have been very unusual.
Therefore, military training of toddlers would not begin to pay off with reasonably competent and capable soldiers for five, ten, or maybe even fifteen years. The average length of military training has varied a lot, from weeks to years, but even five years training before active duty for the average soldier in an army would be unusually long and expensive.
Therefore most societies would not have universal training of children as soldiers beginning as toddlers, considering it a waste of time and money, and your society needs a special reason to begin that practice. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | No.
===
Bodies composed of known materials the size of the Earth and Moon are in ["hydrostatic equilibrium"](https://en.wikipedia.org/wiki/Hydrostatic_equilibrium),
>
> This occurs when external forces such as gravity are balanced by a
> pressure gradient force.[1] For instance, the pressure-gradient force
> prevents gravity from collapsing Earth's atmosphere into a thin, dense
> shell, whereas gravity prevents the pressure gradient force from
> diffusing the atmosphere into space.
>
>
> Hydrostatic equilibrium is the current distinguishing criterion
> between dwarf planets and small Solar System bodies, and has other
> roles in astrophysics and planetary geology. This qualification
> typically means that the object is symmetrically rounded into a
> spheroid or ellipsoid shape, where any irregular surface features are
> due to a relatively thin solid crust. There are 31 observationally
> confirmed such objects (apart from the Sun), sometimes called
> planemos,[2] in the Solar System, seven more[3] that are virtually
> certain, and a hundred or so more that are likely.
>
>
>
What this means in your case is that the strength of the materials is insufficient to support the mass above them. So they flow like molten plastic/liquid and fill all voids.
So in your Scenario the "Earth" outer shell would collapse under its mutual gravitation.
The strength of materials required to prevent this from happening would be quite high and I don't have the time to perform the necessary calculations for you. | **Not without artificial gravity or some other outside source.**
Your mega structure large enough to have an earth sized pocket is going to have a lot of mass. Something that big is going to need futuristic materials and technologies to keep from collapsing.
Anything on the inside of the sphere is going to be drawn toward the center of the structure. If the sphere is off center then everything will be pulled toward one side. If it's in the center of the structure then things would just fall off the surface toward the "sky", unless...
To get gravity on the inside surface of a sphere without artificial gravity it needs to be spinning, meaning the structure needs to be spinning around the sphere, or a mechanism needs to be spinning the earth size sphere independently of the structure.
Spinning the whole structure is not a good idea, since if you have 1g at the surface of the sphere, you'll have even more the further out you go.
Angular Velocity: 0.0118 rotations/minute
Earth Radius: 3959 miles
Gravities: 1g
Radius: 5000 miles
Gravities: 1.26g
Radius: 8000 miles
Gravities: 2g
Stress on the structure would be increased exponentially the further out from the center of gravity you get.
If you just spin the sphere independently you still need super materials like [ringworld scrith](http://larryniven.wikia.com/wiki/Scrith) and you better hope it's really well balanced.
So you'll have to pick your magic: Artificial gravity or impossible building materials.
Edit:
Without artificial gravity you'd need a gravity point source in the center to orbit a moon around, since centripetal force wouldn't work to orbit inside a sphere.
Any variations in mass in the outside structure would tend to destablize the system, similar to the three body problem, requiring constant corrections to keep the moon from crashing.
**With artificial gravity, getting a moon to do anything you want is easy.** |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | Certainly - [the sphere's gravity at the inside will be zero](https://en.wikipedia.org/wiki/Shell_theorem), so the composition and thickness of the crust is irrelevant. The moon has to orbit the central light source, and the mass of the light source should be much bigger than the moon's, and you'd better keep vacuum in the cavity (since there is no gravity, you cannot expect the air to stick close to the crust). Other than that, it's possible. | A mass at the centre and a uniform superstructure of sufficient mass such that the gravitational attraction on any body between the central mass and the superstructure by the central mass equal the attraction due to the superstructure in that direction. There's your answer. ;)
Think of gravity as a set of elastic ropes. The one rope pulling a "moon" towards the central must be balanced by ropes extending from the superstructure in every direction. Calculating these forces will be an infinite series, as the rest of the superstructure will also exert a gravitational attraction towards a moon in between. It is doable, but obviously nothing could live there, unless you build a set of biospheres along the superstructure.
Tidal forces will be a major concern, as will Coriolis forces is the superstructure is spinning. The poles might be liveable; the equator, between the moon-based tides and the structure's own spin, would be like the inside of a washing machine. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | You're describing a [Dyson Sphere](https://en.wikipedia.org/wiki/Dyson_sphere). It is theoretically possible to still have orbital bodies inside the sphere in their orbit around the sun. Assuming we live on the inside of the Dyson shell and can process the entirety of the sun's output without frying, we wouldn't have a moon since the only orbital bodies are the planets further in and the Sun. There's no center of gravity for a moon to orbit around, since the Dyson sphere's center of gravity is the sun itself. That doesn't stop the Venus or Mercury from having moons of their own. | I will answer your bonus question: If the hollow earth is oblate or prolate spheroidal, and the two body system of moon and light source remains in the plane on which the cross section of the hollow earth is still circular, then stable orbits will exist as they would otherwise by symmetry. For a more complicated case, I expect nothing but a series of rather intense numerical simulations could determine the answer to whether there exist any periodic orbits at all. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | No.
===
Bodies composed of known materials the size of the Earth and Moon are in ["hydrostatic equilibrium"](https://en.wikipedia.org/wiki/Hydrostatic_equilibrium),
>
> This occurs when external forces such as gravity are balanced by a
> pressure gradient force.[1] For instance, the pressure-gradient force
> prevents gravity from collapsing Earth's atmosphere into a thin, dense
> shell, whereas gravity prevents the pressure gradient force from
> diffusing the atmosphere into space.
>
>
> Hydrostatic equilibrium is the current distinguishing criterion
> between dwarf planets and small Solar System bodies, and has other
> roles in astrophysics and planetary geology. This qualification
> typically means that the object is symmetrically rounded into a
> spheroid or ellipsoid shape, where any irregular surface features are
> due to a relatively thin solid crust. There are 31 observationally
> confirmed such objects (apart from the Sun), sometimes called
> planemos,[2] in the Solar System, seven more[3] that are virtually
> certain, and a hundred or so more that are likely.
>
>
>
What this means in your case is that the strength of the materials is insufficient to support the mass above them. So they flow like molten plastic/liquid and fill all voids.
So in your Scenario the "Earth" outer shell would collapse under its mutual gravitation.
The strength of materials required to prevent this from happening would be quite high and I don't have the time to perform the necessary calculations for you. | A mass at the centre and a uniform superstructure of sufficient mass such that the gravitational attraction on any body between the central mass and the superstructure by the central mass equal the attraction due to the superstructure in that direction. There's your answer. ;)
Think of gravity as a set of elastic ropes. The one rope pulling a "moon" towards the central must be balanced by ropes extending from the superstructure in every direction. Calculating these forces will be an infinite series, as the rest of the superstructure will also exert a gravitational attraction towards a moon in between. It is doable, but obviously nothing could live there, unless you build a set of biospheres along the superstructure.
Tidal forces will be a major concern, as will Coriolis forces is the superstructure is spinning. The poles might be liveable; the equator, between the moon-based tides and the structure's own spin, would be like the inside of a washing machine. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | Yes, but you need:
* a *very* dense central light source, and this density is in contrast with what we know about sufficiently powerful energy sources, i.e. nuclear fusion. Of course you could go with an artificial light source, such as a degenerate matter sphere which reflects light beamed from the inside of the shell.
* some next-to-uncompressible material with which to build the shell, *or* some mechanical means of counteracting the gravity of the inner sphere and preventing it from making the outer shell collapse (the late [Paul Birch](https://en.wikipedia.org/wiki/Paul_Birch_%28writer%29) suggested a network of rails where heavy carriages would travel at orbital velocities, thus exterting an outward pressure capable of counteracting gravity. Of course, this leaves us with the problem of energizing the network itself.
* some way of keeping the outer shell centered on the light source. The net force exerted by the shell on the central sphere would be zero, which means there's nothing to stop small perturbations to make the central sphere drift against the shell (it's the same reason Niven's Ringworld has stabilizing engines)
* the internal volume should be kept in vacuum, or the Moon's orbit would quickly degrade.
If the perturbations are small enough, it could be feasible to stabilize the shell (and maybe the moon too) using the pressure of the light being beamed from the shell to the "Sun".
However, the central volume would be uninhabitable, as gravity would push towards the "Sun" and the whole cavity would be in vacuum. People on the inside of the shell would need to receive light through thick, airtight glass floors. | A mass at the centre and a uniform superstructure of sufficient mass such that the gravitational attraction on any body between the central mass and the superstructure by the central mass equal the attraction due to the superstructure in that direction. There's your answer. ;)
Think of gravity as a set of elastic ropes. The one rope pulling a "moon" towards the central must be balanced by ropes extending from the superstructure in every direction. Calculating these forces will be an infinite series, as the rest of the superstructure will also exert a gravitational attraction towards a moon in between. It is doable, but obviously nothing could live there, unless you build a set of biospheres along the superstructure.
Tidal forces will be a major concern, as will Coriolis forces is the superstructure is spinning. The poles might be liveable; the equator, between the moon-based tides and the structure's own spin, would be like the inside of a washing machine. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | Certainly - [the sphere's gravity at the inside will be zero](https://en.wikipedia.org/wiki/Shell_theorem), so the composition and thickness of the crust is irrelevant. The moon has to orbit the central light source, and the mass of the light source should be much bigger than the moon's, and you'd better keep vacuum in the cavity (since there is no gravity, you cannot expect the air to stick close to the crust). Other than that, it's possible. | **Not without artificial gravity or some other outside source.**
Your mega structure large enough to have an earth sized pocket is going to have a lot of mass. Something that big is going to need futuristic materials and technologies to keep from collapsing.
Anything on the inside of the sphere is going to be drawn toward the center of the structure. If the sphere is off center then everything will be pulled toward one side. If it's in the center of the structure then things would just fall off the surface toward the "sky", unless...
To get gravity on the inside surface of a sphere without artificial gravity it needs to be spinning, meaning the structure needs to be spinning around the sphere, or a mechanism needs to be spinning the earth size sphere independently of the structure.
Spinning the whole structure is not a good idea, since if you have 1g at the surface of the sphere, you'll have even more the further out you go.
Angular Velocity: 0.0118 rotations/minute
Earth Radius: 3959 miles
Gravities: 1g
Radius: 5000 miles
Gravities: 1.26g
Radius: 8000 miles
Gravities: 2g
Stress on the structure would be increased exponentially the further out from the center of gravity you get.
If you just spin the sphere independently you still need super materials like [ringworld scrith](http://larryniven.wikia.com/wiki/Scrith) and you better hope it's really well balanced.
So you'll have to pick your magic: Artificial gravity or impossible building materials.
Edit:
Without artificial gravity you'd need a gravity point source in the center to orbit a moon around, since centripetal force wouldn't work to orbit inside a sphere.
Any variations in mass in the outside structure would tend to destablize the system, similar to the three body problem, requiring constant corrections to keep the moon from crashing.
**With artificial gravity, getting a moon to do anything you want is easy.** |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | You're describing a [Dyson Sphere](https://en.wikipedia.org/wiki/Dyson_sphere). It is theoretically possible to still have orbital bodies inside the sphere in their orbit around the sun. Assuming we live on the inside of the Dyson shell and can process the entirety of the sun's output without frying, we wouldn't have a moon since the only orbital bodies are the planets further in and the Sun. There's no center of gravity for a moon to orbit around, since the Dyson sphere's center of gravity is the sun itself. That doesn't stop the Venus or Mercury from having moons of their own. | Yes, but you need:
* a *very* dense central light source, and this density is in contrast with what we know about sufficiently powerful energy sources, i.e. nuclear fusion. Of course you could go with an artificial light source, such as a degenerate matter sphere which reflects light beamed from the inside of the shell.
* some next-to-uncompressible material with which to build the shell, *or* some mechanical means of counteracting the gravity of the inner sphere and preventing it from making the outer shell collapse (the late [Paul Birch](https://en.wikipedia.org/wiki/Paul_Birch_%28writer%29) suggested a network of rails where heavy carriages would travel at orbital velocities, thus exterting an outward pressure capable of counteracting gravity. Of course, this leaves us with the problem of energizing the network itself.
* some way of keeping the outer shell centered on the light source. The net force exerted by the shell on the central sphere would be zero, which means there's nothing to stop small perturbations to make the central sphere drift against the shell (it's the same reason Niven's Ringworld has stabilizing engines)
* the internal volume should be kept in vacuum, or the Moon's orbit would quickly degrade.
If the perturbations are small enough, it could be feasible to stabilize the shell (and maybe the moon too) using the pressure of the light being beamed from the shell to the "Sun".
However, the central volume would be uninhabitable, as gravity would push towards the "Sun" and the whole cavity would be in vacuum. People on the inside of the shell would need to receive light through thick, airtight glass floors. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | It's not possible without active intervention.
The sphere's gravity is zero on the inside. So there is no force acting on the moon from the sphere. This would allow the moon to orbit a mass at the center of the planet.
However any perturbation of the sphere would not be transmitted to the moon. Hence nothing prevents the moon, and whatever it is that is in the center for the moon to orbit, to pick up velocity relative to the sphere. | I will answer your bonus question: If the hollow earth is oblate or prolate spheroidal, and the two body system of moon and light source remains in the plane on which the cross section of the hollow earth is still circular, then stable orbits will exist as they would otherwise by symmetry. For a more complicated case, I expect nothing but a series of rather intense numerical simulations could determine the answer to whether there exist any periodic orbits at all. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | Certainly - [the sphere's gravity at the inside will be zero](https://en.wikipedia.org/wiki/Shell_theorem), so the composition and thickness of the crust is irrelevant. The moon has to orbit the central light source, and the mass of the light source should be much bigger than the moon's, and you'd better keep vacuum in the cavity (since there is no gravity, you cannot expect the air to stick close to the crust). Other than that, it's possible. | Yes, but you need:
* a *very* dense central light source, and this density is in contrast with what we know about sufficiently powerful energy sources, i.e. nuclear fusion. Of course you could go with an artificial light source, such as a degenerate matter sphere which reflects light beamed from the inside of the shell.
* some next-to-uncompressible material with which to build the shell, *or* some mechanical means of counteracting the gravity of the inner sphere and preventing it from making the outer shell collapse (the late [Paul Birch](https://en.wikipedia.org/wiki/Paul_Birch_%28writer%29) suggested a network of rails where heavy carriages would travel at orbital velocities, thus exterting an outward pressure capable of counteracting gravity. Of course, this leaves us with the problem of energizing the network itself.
* some way of keeping the outer shell centered on the light source. The net force exerted by the shell on the central sphere would be zero, which means there's nothing to stop small perturbations to make the central sphere drift against the shell (it's the same reason Niven's Ringworld has stabilizing engines)
* the internal volume should be kept in vacuum, or the Moon's orbit would quickly degrade.
If the perturbations are small enough, it could be feasible to stabilize the shell (and maybe the moon too) using the pressure of the light being beamed from the shell to the "Sun".
However, the central volume would be uninhabitable, as gravity would push towards the "Sun" and the whole cavity would be in vacuum. People on the inside of the shell would need to receive light through thick, airtight glass floors. |
27,449 | The [Hollow Earth](http://en.wikipedia.org/wiki/Hollow_Earth) theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, while the "ground" points outward.
Let's assume that we have a planet the size of Earth, except that it is a hollow Earth. In reality, it's simply an Earth-sized cavity inside a larger body, notably, some sort of artificial megastructure. I had assumed that said megastructure was spherical, but clearly I should have stated it explicitly, so I'll do so now. The structure will have spherical symmetry and be as uniform as possible.
Is it possible to put a moon inside the sphere - somewhere between the central light source and the "ground" - and have it move in an "orbit" around the center? Would the moon crash into the ground, or would it be stable?
I'm almost positive that the moon can't be as big as Earth's moon, but I don't know a reasonable size. I'm fine with anything bigger than, say, [Janus](http://en.wikipedia.org/wiki/Janus_(moon)) or [Epimetheus](http://en.wikipedia.org/wiki/Epimetheus_(moon)).
---
Bonus question (not necessary to answer): Is the setup possible if the hollow Earth is non-spherical, i.e. ellipsoidal? | 2015/10/12 | [
"https://worldbuilding.stackexchange.com/questions/27449",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/627/"
] | **Not without artificial gravity or some other outside source.**
Your mega structure large enough to have an earth sized pocket is going to have a lot of mass. Something that big is going to need futuristic materials and technologies to keep from collapsing.
Anything on the inside of the sphere is going to be drawn toward the center of the structure. If the sphere is off center then everything will be pulled toward one side. If it's in the center of the structure then things would just fall off the surface toward the "sky", unless...
To get gravity on the inside surface of a sphere without artificial gravity it needs to be spinning, meaning the structure needs to be spinning around the sphere, or a mechanism needs to be spinning the earth size sphere independently of the structure.
Spinning the whole structure is not a good idea, since if you have 1g at the surface of the sphere, you'll have even more the further out you go.
Angular Velocity: 0.0118 rotations/minute
Earth Radius: 3959 miles
Gravities: 1g
Radius: 5000 miles
Gravities: 1.26g
Radius: 8000 miles
Gravities: 2g
Stress on the structure would be increased exponentially the further out from the center of gravity you get.
If you just spin the sphere independently you still need super materials like [ringworld scrith](http://larryniven.wikia.com/wiki/Scrith) and you better hope it's really well balanced.
So you'll have to pick your magic: Artificial gravity or impossible building materials.
Edit:
Without artificial gravity you'd need a gravity point source in the center to orbit a moon around, since centripetal force wouldn't work to orbit inside a sphere.
Any variations in mass in the outside structure would tend to destablize the system, similar to the three body problem, requiring constant corrections to keep the moon from crashing.
**With artificial gravity, getting a moon to do anything you want is easy.** | I will answer your bonus question: If the hollow earth is oblate or prolate spheroidal, and the two body system of moon and light source remains in the plane on which the cross section of the hollow earth is still circular, then stable orbits will exist as they would otherwise by symmetry. For a more complicated case, I expect nothing but a series of rather intense numerical simulations could determine the answer to whether there exist any periodic orbits at all. |
2,136,109 | I'm starting to modify my app, which uses all hardcoded strings for errors, GUI, etc. I'm considering these two approaches, but let me know if there is an even better way:
-Put all string in ressource (.rc) files.
-define all strings in a file, once for each language. Use a preprocessor define to decide which strings get compiled in.
Which of these two approaches is generally prefered? | 2010/01/25 | [
"https://Stackoverflow.com/questions/2136109",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/204479/"
] | Put all the strings in resource files. Once you've done that, there's several good translation packages available. One useful thing these packages do is allow you to get translation done by somebody who doesn't program.
Remember, also, that internationalization (i18n) is a large subject, and there's a lot of things to consider. It isn't just a matter of translating strings. Do a web search on it, at the very least. You might want to read a book on it: I used *International Programming for Windows* by Schmitt as a guide. It's an old book from Microsoft Press, and I had to get it through a used book service; most of the more modern stuff seems to be on internationalizing .NET apps.
Without knowing more about your project (what sort of software, who the intended audience is, what sort of organization you have, what sort of budget, why you're interested in internationalization, etc.), this is about the most I can tell you. | Generally you see locale specific resource files containing strings referenced by key. Compiling different versions for different locales is a very rigid solution and will be a maintenance nightmare. Using resource files also allows the user to have fallback locales. |
2,136,109 | I'm starting to modify my app, which uses all hardcoded strings for errors, GUI, etc. I'm considering these two approaches, but let me know if there is an even better way:
-Put all string in ressource (.rc) files.
-define all strings in a file, once for each language. Use a preprocessor define to decide which strings get compiled in.
Which of these two approaches is generally prefered? | 2010/01/25 | [
"https://Stackoverflow.com/questions/2136109",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/204479/"
] | Put all the strings in resource files. Once you've done that, there's several good translation packages available. One useful thing these packages do is allow you to get translation done by somebody who doesn't program.
Remember, also, that internationalization (i18n) is a large subject, and there's a lot of things to consider. It isn't just a matter of translating strings. Do a web search on it, at the very least. You might want to read a book on it: I used *International Programming for Windows* by Schmitt as a guide. It's an old book from Microsoft Press, and I had to get it through a used book service; most of the more modern stuff seems to be on internationalizing .NET apps.
Without knowing more about your project (what sort of software, who the intended audience is, what sort of organization you have, what sort of budget, why you're interested in internationalization, etc.), this is about the most I can tell you. | There's another approach of just putting strings in the source with somethign like tr(" ") and usign one of the tools that strips them out and converts them.
It works with any toolkit/GUI library.
You can mark text to be converted and text not to change (such as protocol strings or db keys).
It makes the source easier to read and search, isntead of having to lookup what IDS\_MESSAGE34 means.
One problem with resource files, at least with Windows/MFC, is that you can't use the stringtable in dialogs. So you have some text in the stringtabel and some in the dialog section which you have to dela with separately. |
207,082 | Broadly speaking, a [dry suit](https://en.wikipedia.org/wiki/Dry_suit) is a garment which restricts fluid exchange between the portion of the body covered and the outside environment. These work for humans because it is not unreasonably difficult to achieve a water-resistant seal between the suit material and human skin. (Yes, there are also varieties which completely surround the wearer, but for my purposes I am not interested in that method.)
Alas, people in my world have fur.
They still want dry suits; both for the reasons humans would, and also for other purposes, e.g. the ability to go swimming while needing to protect *limited* parts of the body from water (e.g. due to injuries or... [other reasons](https://en.wikipedia.org/wiki/Kink_(sexuality)), and because this is a harder problem then creating a fully-enclosed suit).
Rules:
* The garment must not require the user to shave; my people's vanity will not stand for such an offense (and it would be very inconvenient).
* Putting on the garment should be relatively easy. Having to part fur to get a good seal is fine. Having to put special goop in one's fur (as long as it will washes out again!) is less desirably, but not categorically unacceptable.
* The garment should restrict ingress to 100 mL or less given a "seam" length of 1 m (e.g. around the waist) and an expected 4-5 hours of use.
* The above only needs to be accomplished to a maximum depth of 5m. (However, if it won't work up to at least 15m, please show why. I'm more interested in swimming pools than deep diving, though.)
* Gravity, pressure, etc. are approximately Earth-normal (close enough to make little difference, anyway). For the purposes of this question, something that would work on a roughly-human-sized animal on Earth is acceptable.
Is a dry suit — or, more generally, a water-resistant seal between a garment and the wearer's *fur-covered* body — still possible, strictly according to science? If "no", but if I also have magic that can continuously repel water with a force of 10 N, does that help? | 2021/07/11 | [
"https://worldbuilding.stackexchange.com/questions/207082",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/43697/"
] | **Vaseline**
Your creature's vanity be damned, your only option other than shaving is to use a gel such as Vaseline to create a gasket the suit can bond to. The seals will still need to be tight and you will always have a pressure limitation that's less than what could be achieved with skin alone — but it would work.
The gel would need to be worked into the fur such that it coated the fur to the skin and was wider than the seal band on both the inside and the outside.
**Then add a vacuum**
On top of this, design the seals to produce a vacuum. It need not be electrical. A lever (not unlike those found on suction cups) would be enough. Removing the oxygen within the seal would improve the quality of the seal (like suction cups). If you adopt this aspect, the seals would need to be flexible enough to form to the shape of the body. | The same way as thinly haired humans do.
----------------------------------------
(Assuming of course that when you say 'furred' you mean a normal layer of fur as per the average animal not thick fur like that of a yak, polar bear or lions mane etc.)
Just use slightly longer and (more importantly) *tighter* neoprene, silicon or latex seals where needed as well as a thick layer of Vaseline rubbed into the fur under the seals. And go with one piece dry suits and one piece neoprene undergarments. Between the undergarment and the fur your characters should stay warmer and dryer than normal divers because all fur is slightly water resistant and provides an extra layer of insulation via the air it traps.
But remember normal dry suits do leak at least a *little* because the water tight seals are never perfect. |
292 | I'm here on the mobile site via my phone, but can't find any manner of search box anywhere. I must be looking in Alderaan places.
Is the search box stripped from the mobile site? Any ideas (besides the last resort of using the desktop site on mobile)? | 2012/12/18 | [
"https://avp.meta.stackexchange.com/questions/292",
"https://avp.meta.stackexchange.com",
"https://avp.meta.stackexchange.com/users/3323/"
] | In the upper right hand corner there is a small square box with a triangle pointing down. Click the triangle and the search box and login link will appear below it.
 | If you've got yourself enough screen real-estate, you can also just switch to the full site.
Scroll down to the bottom...
 |
908 | Does anyone know if it is possible to get the PCSXR (Playstation 1) emulator to work on the Raspberry Pi? On both Debian Squeeze and Wheezy, running any game on it with the xvideo plugin just gives.
>
> RGB & YUV not found. Quitting.
>
>
>
I presume this is something to do with the proprietary driver / firmware not working with xvideo. The only other plugin is OpenGL (not es though), so i don't think that will work. Has anyone been able to get this to work on the Raspberry Pi? | 2012/07/03 | [
"https://raspberrypi.stackexchange.com/questions/908",
"https://raspberrypi.stackexchange.com",
"https://raspberrypi.stackexchange.com/users/495/"
] | [PCSX-ReARMed](http://notaz.gp2x.de/pcsx_rearmed.php) should be already runnable on the Raspberry Pi. In [this thread](http://www.raspberrypi.org/phpBB3/viewtopic.php?f=35&t=13349) people says that it compiles fine but it's a little bit slow, still playable though.
Here a couple of youtube videos that show the smoothness of two games: [Crash Bandicoot](http://www.youtube.com/watch?v=eQDt_Ijj11U) and [Dragon Ball GT Final Bout](http://www.youtube.com/watch?v=ASmCLkpGdQg).
As someone already said, now the Raspberry Pi is the cheapest Playstation console ever! :) | On desktop Ubuntu the fix for the same error is under the Configuration Menu, select Plugins & BIOS then change the Graphics dropdown from
XVideo Driver" to "OpenGL Driver".
[I wrote about this and another error that often comes afterwards here](http://blog.ryanhalliday.com/2018/02/pcsxr-errors.html) |
78,283 | 4+ light years away, aliens living on [Proxima Centauri B](https://en.wikipedia.org/wiki/Proxima_Centauri_b) have space travel and incredible technology, but are not interested in traveling out of their system or in returning our radio-babble, rather going about their business.
They have built in their solar system a very large structure as a cultural monument.
With today's technology, would this necessarily have to be the size of a planet for us to 'notice' a new structure, or could it be smaller? **How large does an artificial structure need to be for us to detect it** — and could there be a known material/mineral/etc. to enhance a smaller object?
EDIT: we are only 4+ light years away; not 12. | 2017/04/16 | [
"https://worldbuilding.stackexchange.com/questions/78283",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/3276/"
] | The easiest way of detecting a solid object in other star system is observing the weakening of the light of its star as it passes before it. The majority of exoplanets were discovered this way. So a thin dish having the diameter of some thousand kilometers would be ideal choice. But this works only if its orbit intersects the line between Proxima centaury and Earth. If the aliens don't want to send message to us, their construct might never passes before the star from our POV.
The other solution is to make the object emit very strong radiation on its own. This would mean a very high power energy source. Since they probably can not construct a new star, it would only radiate in a collimated beam, but will slowly sweep the full sky. This acts as a monument for the civilization, but is not a directed message for us. | The question doesn’t have a simple, single, answer.
If you browse through the videos for the SETI Weekly Colloqiums (best on YouTube), you’ll learn all about detection and instruments, including those hunting exoplanets.
You will see that the ability to detect can be a function not just of the size of the object (radius or mass, depending on the method) but on its orbital parameters and the characteristics of the star. You also have the albedo of the object to consider!
Planets can be detected *much* smaller than the ability to resolve as a disk with an optical instrument.
The case for a very small object that I can think of is an exo*moon*. The planet is large/close/fast enough to detect with transits. But jitter in the timing of those transits is explained by the planet wobbling slightly due to a moon.
Detecting this is dependant on the nature of its primary, such that the planet is detected — not just being big enough relative to the primary to make it wobble. |
78,283 | 4+ light years away, aliens living on [Proxima Centauri B](https://en.wikipedia.org/wiki/Proxima_Centauri_b) have space travel and incredible technology, but are not interested in traveling out of their system or in returning our radio-babble, rather going about their business.
They have built in their solar system a very large structure as a cultural monument.
With today's technology, would this necessarily have to be the size of a planet for us to 'notice' a new structure, or could it be smaller? **How large does an artificial structure need to be for us to detect it** — and could there be a known material/mineral/etc. to enhance a smaller object?
EDIT: we are only 4+ light years away; not 12. | 2017/04/16 | [
"https://worldbuilding.stackexchange.com/questions/78283",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/3276/"
] | The easiest way of detecting a solid object in other star system is observing the weakening of the light of its star as it passes before it. The majority of exoplanets were discovered this way. So a thin dish having the diameter of some thousand kilometers would be ideal choice. But this works only if its orbit intersects the line between Proxima centaury and Earth. If the aliens don't want to send message to us, their construct might never passes before the star from our POV.
The other solution is to make the object emit very strong radiation on its own. This would mean a very high power energy source. Since they probably can not construct a new star, it would only radiate in a collimated beam, but will slowly sweep the full sky. This acts as a monument for the civilization, but is not a directed message for us. | About the size and mass of Earth
================================
Exoplanet discovery hasn't quite dropped below the "about earth sized" detection limit yet, and [we've already detected one, possibly two or three, exoplanets](https://en.wikipedia.org/wiki/Alpha_Centauri#Planets) in orbit around the Alpha Centauri system.
Proxima Centauri b (aka or Alpha Centauri Cb) is approximately 1.27 Earth masses with a radius between 0.8 and 1.5 Earth's. Although the data only gives a *minimum* value on the mass.
There are also two other possible detections (that unlike Alpha Centauri Bb haven't been ruled a data anomaly yet), one of which has a radius of about 0.92 Earth's. I can't find a whole lot of information about these.
Detecting anything smaller or less massive than that is beyond current technology and even current technology is based on very precise measurements that are prone to error (as evidenced by Alpha Centauri Bb). It's the equivalent of measuring the light intensity of a lighthouse beacon vs. the same beacon with a single poppy seed placed in front of it. Which is why there are such precise measurements on the *radius* of exoplanets but not their *mass.*
Now, if your alien civilization was building something like a [Dyson Swarm](https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_swarm) we here on Earth would probably start picking that up as soon as the light level of the star dipped significantly. Most exoplanet research is done with observations over the period of weeks or months, so without one of those aimed at the Alpha Centauri system, you'd have to wait on the less focused observations to pick up the dimminig. But a dyson swarm could do that pretty easily with little mass involved, simply by congregating on one side of the star. But at the same time, such a swarm could easily *avoid* being detected simply by making sure it is sufficiently diffuse.
How quickly that would get noticed? No idea. Assuming that at 100% light absorption that any Joe on the street with his naked eye notices that the star is missing in a few seconds and that at 0% light absorption, even the exoplanet research teams see nothing wrong after 6 months of study, then there exists some value X between these two extremes such that someone, somewhere, eventually notices and the scientific community starts aiming more powerful telescopes at the system to see what's up (and even then they might only be able to conclude that "something is happening" because the actual image of the system is still only pixels in size, but 1% dimmer than a year ago!). |
78,283 | 4+ light years away, aliens living on [Proxima Centauri B](https://en.wikipedia.org/wiki/Proxima_Centauri_b) have space travel and incredible technology, but are not interested in traveling out of their system or in returning our radio-babble, rather going about their business.
They have built in their solar system a very large structure as a cultural monument.
With today's technology, would this necessarily have to be the size of a planet for us to 'notice' a new structure, or could it be smaller? **How large does an artificial structure need to be for us to detect it** — and could there be a known material/mineral/etc. to enhance a smaller object?
EDIT: we are only 4+ light years away; not 12. | 2017/04/16 | [
"https://worldbuilding.stackexchange.com/questions/78283",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/3276/"
] | It depends on, what we understand on "detect it".
If it means: "we can detect it anyhow", then the answer is, we should use simple, ideally focused radio signals for communication. Any radio telescope (or sender) would be enough, and the answer is: some meters. (Unrelated, but important: if any civilization would exist in the outer space using a similar radio technology as we do, we would mutually detect eachother from around 100 light years. Sad truth is that there is radio silence.)
If it means: "we can see it in visible light", then it depends from its temperature. The maximal thermal radiation is around at 6000K in visible light (which is not surprising - our eye was evolved below the Sun). In this case, all depends on, how near is it to the Alpha Centauri. The limit of the current exoplanet detectors is in the order of Earth-sized bodies, although these aren't so hot. If something heats this body to 6000K, then it may be visible already if it is only Moon-sized. The object would be point-like in any current telescope.
If it means: "seeing it as a multi-pixel object", the answer is around Sun-size. | The question doesn’t have a simple, single, answer.
If you browse through the videos for the SETI Weekly Colloqiums (best on YouTube), you’ll learn all about detection and instruments, including those hunting exoplanets.
You will see that the ability to detect can be a function not just of the size of the object (radius or mass, depending on the method) but on its orbital parameters and the characteristics of the star. You also have the albedo of the object to consider!
Planets can be detected *much* smaller than the ability to resolve as a disk with an optical instrument.
The case for a very small object that I can think of is an exo*moon*. The planet is large/close/fast enough to detect with transits. But jitter in the timing of those transits is explained by the planet wobbling slightly due to a moon.
Detecting this is dependant on the nature of its primary, such that the planet is detected — not just being big enough relative to the primary to make it wobble. |
78,283 | 4+ light years away, aliens living on [Proxima Centauri B](https://en.wikipedia.org/wiki/Proxima_Centauri_b) have space travel and incredible technology, but are not interested in traveling out of their system or in returning our radio-babble, rather going about their business.
They have built in their solar system a very large structure as a cultural monument.
With today's technology, would this necessarily have to be the size of a planet for us to 'notice' a new structure, or could it be smaller? **How large does an artificial structure need to be for us to detect it** — and could there be a known material/mineral/etc. to enhance a smaller object?
EDIT: we are only 4+ light years away; not 12. | 2017/04/16 | [
"https://worldbuilding.stackexchange.com/questions/78283",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/3276/"
] | It depends on, what we understand on "detect it".
If it means: "we can detect it anyhow", then the answer is, we should use simple, ideally focused radio signals for communication. Any radio telescope (or sender) would be enough, and the answer is: some meters. (Unrelated, but important: if any civilization would exist in the outer space using a similar radio technology as we do, we would mutually detect eachother from around 100 light years. Sad truth is that there is radio silence.)
If it means: "we can see it in visible light", then it depends from its temperature. The maximal thermal radiation is around at 6000K in visible light (which is not surprising - our eye was evolved below the Sun). In this case, all depends on, how near is it to the Alpha Centauri. The limit of the current exoplanet detectors is in the order of Earth-sized bodies, although these aren't so hot. If something heats this body to 6000K, then it may be visible already if it is only Moon-sized. The object would be point-like in any current telescope.
If it means: "seeing it as a multi-pixel object", the answer is around Sun-size. | About the size and mass of Earth
================================
Exoplanet discovery hasn't quite dropped below the "about earth sized" detection limit yet, and [we've already detected one, possibly two or three, exoplanets](https://en.wikipedia.org/wiki/Alpha_Centauri#Planets) in orbit around the Alpha Centauri system.
Proxima Centauri b (aka or Alpha Centauri Cb) is approximately 1.27 Earth masses with a radius between 0.8 and 1.5 Earth's. Although the data only gives a *minimum* value on the mass.
There are also two other possible detections (that unlike Alpha Centauri Bb haven't been ruled a data anomaly yet), one of which has a radius of about 0.92 Earth's. I can't find a whole lot of information about these.
Detecting anything smaller or less massive than that is beyond current technology and even current technology is based on very precise measurements that are prone to error (as evidenced by Alpha Centauri Bb). It's the equivalent of measuring the light intensity of a lighthouse beacon vs. the same beacon with a single poppy seed placed in front of it. Which is why there are such precise measurements on the *radius* of exoplanets but not their *mass.*
Now, if your alien civilization was building something like a [Dyson Swarm](https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_swarm) we here on Earth would probably start picking that up as soon as the light level of the star dipped significantly. Most exoplanet research is done with observations over the period of weeks or months, so without one of those aimed at the Alpha Centauri system, you'd have to wait on the less focused observations to pick up the dimminig. But a dyson swarm could do that pretty easily with little mass involved, simply by congregating on one side of the star. But at the same time, such a swarm could easily *avoid* being detected simply by making sure it is sufficiently diffuse.
How quickly that would get noticed? No idea. Assuming that at 100% light absorption that any Joe on the street with his naked eye notices that the star is missing in a few seconds and that at 0% light absorption, even the exoplanet research teams see nothing wrong after 6 months of study, then there exists some value X between these two extremes such that someone, somewhere, eventually notices and the scientific community starts aiming more powerful telescopes at the system to see what's up (and even then they might only be able to conclude that "something is happening" because the actual image of the system is still only pixels in size, but 1% dimmer than a year ago!). |
78,283 | 4+ light years away, aliens living on [Proxima Centauri B](https://en.wikipedia.org/wiki/Proxima_Centauri_b) have space travel and incredible technology, but are not interested in traveling out of their system or in returning our radio-babble, rather going about their business.
They have built in their solar system a very large structure as a cultural monument.
With today's technology, would this necessarily have to be the size of a planet for us to 'notice' a new structure, or could it be smaller? **How large does an artificial structure need to be for us to detect it** — and could there be a known material/mineral/etc. to enhance a smaller object?
EDIT: we are only 4+ light years away; not 12. | 2017/04/16 | [
"https://worldbuilding.stackexchange.com/questions/78283",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/3276/"
] | About the size and mass of Earth
================================
Exoplanet discovery hasn't quite dropped below the "about earth sized" detection limit yet, and [we've already detected one, possibly two or three, exoplanets](https://en.wikipedia.org/wiki/Alpha_Centauri#Planets) in orbit around the Alpha Centauri system.
Proxima Centauri b (aka or Alpha Centauri Cb) is approximately 1.27 Earth masses with a radius between 0.8 and 1.5 Earth's. Although the data only gives a *minimum* value on the mass.
There are also two other possible detections (that unlike Alpha Centauri Bb haven't been ruled a data anomaly yet), one of which has a radius of about 0.92 Earth's. I can't find a whole lot of information about these.
Detecting anything smaller or less massive than that is beyond current technology and even current technology is based on very precise measurements that are prone to error (as evidenced by Alpha Centauri Bb). It's the equivalent of measuring the light intensity of a lighthouse beacon vs. the same beacon with a single poppy seed placed in front of it. Which is why there are such precise measurements on the *radius* of exoplanets but not their *mass.*
Now, if your alien civilization was building something like a [Dyson Swarm](https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_swarm) we here on Earth would probably start picking that up as soon as the light level of the star dipped significantly. Most exoplanet research is done with observations over the period of weeks or months, so without one of those aimed at the Alpha Centauri system, you'd have to wait on the less focused observations to pick up the dimminig. But a dyson swarm could do that pretty easily with little mass involved, simply by congregating on one side of the star. But at the same time, such a swarm could easily *avoid* being detected simply by making sure it is sufficiently diffuse.
How quickly that would get noticed? No idea. Assuming that at 100% light absorption that any Joe on the street with his naked eye notices that the star is missing in a few seconds and that at 0% light absorption, even the exoplanet research teams see nothing wrong after 6 months of study, then there exists some value X between these two extremes such that someone, somewhere, eventually notices and the scientific community starts aiming more powerful telescopes at the system to see what's up (and even then they might only be able to conclude that "something is happening" because the actual image of the system is still only pixels in size, but 1% dimmer than a year ago!). | The question doesn’t have a simple, single, answer.
If you browse through the videos for the SETI Weekly Colloqiums (best on YouTube), you’ll learn all about detection and instruments, including those hunting exoplanets.
You will see that the ability to detect can be a function not just of the size of the object (radius or mass, depending on the method) but on its orbital parameters and the characteristics of the star. You also have the albedo of the object to consider!
Planets can be detected *much* smaller than the ability to resolve as a disk with an optical instrument.
The case for a very small object that I can think of is an exo*moon*. The planet is large/close/fast enough to detect with transits. But jitter in the timing of those transits is explained by the planet wobbling slightly due to a moon.
Detecting this is dependant on the nature of its primary, such that the planet is detected — not just being big enough relative to the primary to make it wobble. |
1,789,339 | What could be good list of failure scenaros for testing a reliable UDP layer? I have thought of the below cases:
* Drop Data packets
* Drop ACK, NAK Packets
* Send packets in out of sequence.
* Drop intial hand shaking packets
* Drop close / shutdown packets
* Duplicate packets
Please help in identifying other cases that reliable UDP needs to handle? | 2009/11/24 | [
"https://Stackoverflow.com/questions/1789339",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/217726/"
] | Have you tried intentionally corrupting packets in transit?
Also, have you considered a scenario where only one-way communication is possible? In this case, the sending host thinks that the send failed, but the receiving end successfully processes the message. For instance:
1. host **A** sends a message to host **B**
2. **B** successfully receives message and replies with ACK
3. ACK gets dropped in the network
4. **A** waits for timeout and re-sends message (repeats steps 1-3)
5. host **A** exceeds retry count and thinks the send failed, but host **B** has in fact processed the message | I have thought UDP is a connectionless and unreliable protocol and that is does not require and specific transport handshake between hosts. And hence there is no such thing as a reliable UDP protocol. |
1,789,339 | What could be good list of failure scenaros for testing a reliable UDP layer? I have thought of the below cases:
* Drop Data packets
* Drop ACK, NAK Packets
* Send packets in out of sequence.
* Drop intial hand shaking packets
* Drop close / shutdown packets
* Duplicate packets
Please help in identifying other cases that reliable UDP needs to handle? | 2009/11/24 | [
"https://Stackoverflow.com/questions/1789339",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/217726/"
] | The list you've given sounds pretty good. Also think about:
* Very delayed packets (where most packets come through fine, but one or two are delayed by several minutes);
* Very delayed duplicates (where the original came through quickly, but the duplicate arrived after several minutes delay);
* Silent dropping of all packets above a certain size (both unidirectional and bidirectional cases);
* Highly variable delays;
* Sequence number wrapping tests. | Have you tried intentionally corrupting packets in transit?
Also, have you considered a scenario where only one-way communication is possible? In this case, the sending host thinks that the send failed, but the receiving end successfully processes the message. For instance:
1. host **A** sends a message to host **B**
2. **B** successfully receives message and replies with ACK
3. ACK gets dropped in the network
4. **A** waits for timeout and re-sends message (repeats steps 1-3)
5. host **A** exceeds retry count and thinks the send failed, but host **B** has in fact processed the message |
1,789,339 | What could be good list of failure scenaros for testing a reliable UDP layer? I have thought of the below cases:
* Drop Data packets
* Drop ACK, NAK Packets
* Send packets in out of sequence.
* Drop intial hand shaking packets
* Drop close / shutdown packets
* Duplicate packets
Please help in identifying other cases that reliable UDP needs to handle? | 2009/11/24 | [
"https://Stackoverflow.com/questions/1789339",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/217726/"
] | The list you've given sounds pretty good. Also think about:
* Very delayed packets (where most packets come through fine, but one or two are delayed by several minutes);
* Very delayed duplicates (where the original came through quickly, but the duplicate arrived after several minutes delay);
* Silent dropping of all packets above a certain size (both unidirectional and bidirectional cases);
* Highly variable delays;
* Sequence number wrapping tests. | I have thought UDP is a connectionless and unreliable protocol and that is does not require and specific transport handshake between hosts. And hence there is no such thing as a reliable UDP protocol. |
10,200,082 | I created a couple web services for my app as follows.
1. Allows a host device to send its information to the web service and will store it in a sql database.
2. Allows a client device to see all nearby devices based on the information in the sql database.
I want the client to now be able to click one of the devices to connect to, which would then somehow link the two together. The question I have is right now my web services can only send a response to a device's request. What I want is if the host device maybe presses a button, it will send that info to the web service, which will then send some information to the client who previously connected.
How can I accomplish sending information from a web service to a device that hasn't requested anything?
Background info:
I am using a php based web service and ASIHTTPRequest to send and receive the information on the iphone side. | 2012/04/17 | [
"https://Stackoverflow.com/questions/10200082",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/904355/"
] | In 99% of cases, you're going to want to use polling. Think of any application that gets messages (email, Words with Friends, whatever). They all call the server and ask "are there any new messages for me?" You'll have to figure out the right frequency for your application.
In the rare case where you need near realtime communication, then you'll need to setup your app to run as a server. See here: [What classes do I use to make an iPhone act as a server?](https://stackoverflow.com/questions/478719/what-classes-do-i-use-to-make-an-iphone-act-as-a-server). Obviously the battery and bandwidth cost of this is much higher. | You could probably keep a persistent connection open, but this is going to break when network conditions change (such as when moving from network to network, on/off cellular, etc.).
The client could poll the server at rapid intervals, but this will not only incur a higher than desirable load on your server but, much more importantly, burn through the client device's battery. (Doubly so on 3G since the cellular radio has a fairly lengthy minimum power-up interval regardless of how small a network transaction might be.)
If you are talking about fairly sporadic updates (real-time updates really would call for the first option above, with appropriate error handling and reconnection if a TCP session is killed), you might consider [Apple Push Notifications](https://developer.apple.com/library/mac/#documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/ApplePushService/ApplePushService.html) - provided that the notification payload is consistent with the APNS guidelines. They would behave almost exactly as you describe. |
7,786 | I have asked the very same question about Belgium. I really liked the answers I got from [Must see places while going through Belgium](https://travel.stackexchange.com/questions/7553/must-see-places-while-going-through-belgium)
**Edit:** I will be traveling by car from Baltics to Netherlands or Belgium with a group of 6 people, ages varies from 20 - 50. Our direction really depends on the weather and we'll start working our way back from there. One way or another we will be interested in the middle part of Germany (part between Hannover and Nürnberg).
We don't have anything special were interested in, we would just like to see as much as possible while driving back to the Baltics. Also we would like to avoid tourist traps where one could possibly spend a whole day, like amusement parks, big cities, bars & pubs etc.
We're looking sights where we could basically drive through (spend an hour or two and then move on). We're interested in anything that makes average Joe from another country go "wow" one way or another.
Earlier years we've used technique where we've looked POI's 50-100 km along the route from GPS and going through the country in a flowing manner.
Some style examples we've liked: Hill of crosses in Lithuania, Wieliczka salt mine, windmills in Netherlands, some great Castles, Nature beauty
[Answer I liked from Belgium thread](https://travel.stackexchange.com/a/7560/2515)
What are a must-see places in Germany (middle section)? | 2012/06/17 | [
"https://travel.stackexchange.com/questions/7786",
"https://travel.stackexchange.com",
"https://travel.stackexchange.com/users/2515/"
] | Since Bayreuth lies almost directly in your path of travel, you would almost certainly want to take in the [Margravial Opera House](http://en.wikipedia.org/wiki/Margravial_Opera_House), which is one of the most dazzling examples of high baroque architecture in central Europe. The inside of the threatre is breath-takingly opulent. [Bayreuth](http://en.wikipedia.org/wiki/Bayreuth) also has a few other 'surprises', not to mention [Bavarian cuisine](http://en.wikipedia.org/wiki/Schlachtsch%C3%BCssel). Avoid Bayreuth in August. | Driving along the Rhine river (between Mainz and Koblenz), there are a lot of "must-see-places" especially [Rüdesheim](http://en.wikipedia.org/wiki/R%C3%BCdesheim_am_Rhein) and [Loreley](http://en.wikipedia.org/wiki/Loreley). I have been there more than 20 times, and I am still loving it |
7,786 | I have asked the very same question about Belgium. I really liked the answers I got from [Must see places while going through Belgium](https://travel.stackexchange.com/questions/7553/must-see-places-while-going-through-belgium)
**Edit:** I will be traveling by car from Baltics to Netherlands or Belgium with a group of 6 people, ages varies from 20 - 50. Our direction really depends on the weather and we'll start working our way back from there. One way or another we will be interested in the middle part of Germany (part between Hannover and Nürnberg).
We don't have anything special were interested in, we would just like to see as much as possible while driving back to the Baltics. Also we would like to avoid tourist traps where one could possibly spend a whole day, like amusement parks, big cities, bars & pubs etc.
We're looking sights where we could basically drive through (spend an hour or two and then move on). We're interested in anything that makes average Joe from another country go "wow" one way or another.
Earlier years we've used technique where we've looked POI's 50-100 km along the route from GPS and going through the country in a flowing manner.
Some style examples we've liked: Hill of crosses in Lithuania, Wieliczka salt mine, windmills in Netherlands, some great Castles, Nature beauty
[Answer I liked from Belgium thread](https://travel.stackexchange.com/a/7560/2515)
What are a must-see places in Germany (middle section)? | 2012/06/17 | [
"https://travel.stackexchange.com/questions/7786",
"https://travel.stackexchange.com",
"https://travel.stackexchange.com/users/2515/"
] | What you call the "middle section" is still quite vast. Here is a proposal.
From Belgium, you can transit via Luxembourg and then head to [Trier](http://en.wikipedia.org/wiki/Trier), Germany's oldest city. It has among the finest Roman relics north of the Alps, such as e.g, an amphitheater and public bathes.
Continue southwards to Völklingen. There you can visit the famous and impressive [Völklinger Hütte](http://www.voelklinger-huette.org/en/welcome/) (Ironworks), an important piece of industrial heritage.
Then you will cross the [Pfalz (Palatinate)](http://en.wikipedia.org/wiki/Palatinate_%28region%29). On your way you can visit the [Trifels Castle](http://en.wikipedia.org/wiki/Trifels_Castle). The Palatinate is home to some of Germany's finest red and white wines. Don't forget to try the [Saumagen](http://en.wikipedia.org/wiki/Saumagen), a local specialty. The [Speyer cathedral](http://en.wikipedia.org/wiki/Speyer_Cathedral) is worth a visit too.
Next head to Nürnberg. If you are interested, you can can pay a visit to the [technical museum in Sinsheim](http://www.technik-museum.de/en). The famous [Hockenheim Ring](http://www.hockenheimring.net/en) is on your way too. Depending on the agenda and your interests it might be worth a stop.
[Nürnberg](http://en.wikipedia.org/wiki/Nuremberg) has a nice old town dominated by the [imperial castle](http://en.wikipedia.org/wiki/Nuremberg_Castle). For me, the most impressive sight is the [Nazi Party Rally Ground](http://www.museums.nuremberg.de/documentation-centre/index.html) ([Reichsparteitagsgelände](http://en.wikipedia.org/wiki/Nazi_party_rally_grounds)). Definitely worth a stop and even a detour.
Some 60 kilometers north of Nürnberg, stop in [Bamberg](http://en.wikipedia.org/wiki/Bamberg). This city has quite a big and well-preserved historical center. Very picturesque.
My next stop would be [Dresden](http://en.wikipedia.org/wiki/Dresden), with its world famous historical monuments (Frauenkirche, Zwinger, ...).
After Dresden, and beofre going to Poalnd, go to the [Spreewald](http://en.wikipedia.org/wiki/Spreewald). This is a very special place. After the driving so much you will be able to breathe some fresh air. In Summer you can have a [boat tour](http://www.spreewald.de/active-fit/exploring-by-water/index.html) on the numerous waterways. In Winter, ice-skates are indicated rather than punts. | Driving along the Rhine river (between Mainz and Koblenz), there are a lot of "must-see-places" especially [Rüdesheim](http://en.wikipedia.org/wiki/R%C3%BCdesheim_am_Rhein) and [Loreley](http://en.wikipedia.org/wiki/Loreley). I have been there more than 20 times, and I am still loving it |
7,786 | I have asked the very same question about Belgium. I really liked the answers I got from [Must see places while going through Belgium](https://travel.stackexchange.com/questions/7553/must-see-places-while-going-through-belgium)
**Edit:** I will be traveling by car from Baltics to Netherlands or Belgium with a group of 6 people, ages varies from 20 - 50. Our direction really depends on the weather and we'll start working our way back from there. One way or another we will be interested in the middle part of Germany (part between Hannover and Nürnberg).
We don't have anything special were interested in, we would just like to see as much as possible while driving back to the Baltics. Also we would like to avoid tourist traps where one could possibly spend a whole day, like amusement parks, big cities, bars & pubs etc.
We're looking sights where we could basically drive through (spend an hour or two and then move on). We're interested in anything that makes average Joe from another country go "wow" one way or another.
Earlier years we've used technique where we've looked POI's 50-100 km along the route from GPS and going through the country in a flowing manner.
Some style examples we've liked: Hill of crosses in Lithuania, Wieliczka salt mine, windmills in Netherlands, some great Castles, Nature beauty
[Answer I liked from Belgium thread](https://travel.stackexchange.com/a/7560/2515)
What are a must-see places in Germany (middle section)? | 2012/06/17 | [
"https://travel.stackexchange.com/questions/7786",
"https://travel.stackexchange.com",
"https://travel.stackexchange.com/users/2515/"
] | The [Landschaftspark in Duisburg](http://en.landschaftspark.de/startseite) is an outstanding place on the industrial route. It's an old, closed steel mill with surrounding buildings. It's free and open round-the-clock, which makes it a thrilling experience as you walk up one of the towers in the middle of the night and completely on your own. It's nicely lit, but you'd better take a torch.
 | Driving along the Rhine river (between Mainz and Koblenz), there are a lot of "must-see-places" especially [Rüdesheim](http://en.wikipedia.org/wiki/R%C3%BCdesheim_am_Rhein) and [Loreley](http://en.wikipedia.org/wiki/Loreley). I have been there more than 20 times, and I am still loving it |
38,645 | As currently, we are having coverage for P1 test cases for an end to end scenarios. We are following the test pyramid strategy. But now we are planning to cover the customer bugs. So just want to know whether we need to provide automation coverage for all bugs or not. | 2019/04/06 | [
"https://sqa.stackexchange.com/questions/38645",
"https://sqa.stackexchange.com",
"https://sqa.stackexchange.com/users/37975/"
] | Recently been in similar situation and after analysis found an interesting co- relation of bugs found.
>
> **The result of the analysis was bugs hide in clusters mostly in few
> specific areas only**.
>
>
>
In other words bugs are not scattered all across the application but mostly exist in clusters in few area only.
So instead of mapping 1 to 1 to each production bug , we added/updated few end to end scenarios in these areas covering most of these issues path + few additional related validations.
This is working very well now as we are finding most of these bugs (if any) in regression test runs only. And automation is being considered very effective by business analysts as well. | It depends
----------
It depends on your system functionality, your current test case coverage, your current test type allocation (based on the testing pyramid and the Agile Testing
Quadrants
[](https://i.stack.imgur.com/mnXeo.jpg)
[](https://i.stack.imgur.com/SBEPg.png)
Your basic choice is always: Update an existing unit/integrated/UI tests or create a new unit/integrated/UI test. Yo should do that in the following order which prioritizes updates existing tests over creating new ones and also prioritizes unit over integration and both over UI testing - the slowest and least reliable form. The order means that if you can do a low level tests instead of a high level one, you should do that
* Review the existing Unit cases and see if a specific example is missing
else
* Add a brand new Unit test case
else
* Review the existing Integration tests and see if a specific example is missing
else
* Add a brand new integration test
else
* Review the existing UI tests and see if a specific example is missing
else
* Add a brand new UI case
else
* Add a new manual test case
else
* Add new items to the exploratory testing charter |
38,645 | As currently, we are having coverage for P1 test cases for an end to end scenarios. We are following the test pyramid strategy. But now we are planning to cover the customer bugs. So just want to know whether we need to provide automation coverage for all bugs or not. | 2019/04/06 | [
"https://sqa.stackexchange.com/questions/38645",
"https://sqa.stackexchange.com",
"https://sqa.stackexchange.com/users/37975/"
] | It depends
----------
It depends on your system functionality, your current test case coverage, your current test type allocation (based on the testing pyramid and the Agile Testing
Quadrants
[](https://i.stack.imgur.com/mnXeo.jpg)
[](https://i.stack.imgur.com/SBEPg.png)
Your basic choice is always: Update an existing unit/integrated/UI tests or create a new unit/integrated/UI test. Yo should do that in the following order which prioritizes updates existing tests over creating new ones and also prioritizes unit over integration and both over UI testing - the slowest and least reliable form. The order means that if you can do a low level tests instead of a high level one, you should do that
* Review the existing Unit cases and see if a specific example is missing
else
* Add a brand new Unit test case
else
* Review the existing Integration tests and see if a specific example is missing
else
* Add a brand new integration test
else
* Review the existing UI tests and see if a specific example is missing
else
* Add a brand new UI case
else
* Add a new manual test case
else
* Add new items to the exploratory testing charter | 1. My first question to you - what is your criteria for regression tests? How do you choose what to automate and what to not? I guess you don't have it, because it should answer your own question. It is not a problem to automate something, it is challenge **to automate the right test cases**. We learn from bugs raised by customers, but only in few cases we really need to automate them.
2. Since we cannot automate everything **typical** criteria for e2e is to automate
1) only standard features
2) high risk
3) most used
3. If you are living in agile world, I would suggest you to read a book "[Agile testing](https://agiletester.ca)" by Janet Gregory & Lisa Crispin. In their book they have several chapters on **Agile Quadrants** and chapter on **Test Automation Strategy**. They suggest to write e2e tests for epics, integration tests for stories and unit tests for tasks.
4. Another idea would be to take free training on [Test Automation Strategy](http://angiejones.tech/test-automation-strategy/) at [Test Automation University](https://testautomationu.applitools.com).
5. More test automation strategy modules, collected by Lisa Crispin you will find on [JoeColantonio](https://www.joecolantonio.com/modeling-automation-2/) website. |
38,645 | As currently, we are having coverage for P1 test cases for an end to end scenarios. We are following the test pyramid strategy. But now we are planning to cover the customer bugs. So just want to know whether we need to provide automation coverage for all bugs or not. | 2019/04/06 | [
"https://sqa.stackexchange.com/questions/38645",
"https://sqa.stackexchange.com",
"https://sqa.stackexchange.com/users/37975/"
] | Recently been in similar situation and after analysis found an interesting co- relation of bugs found.
>
> **The result of the analysis was bugs hide in clusters mostly in few
> specific areas only**.
>
>
>
In other words bugs are not scattered all across the application but mostly exist in clusters in few area only.
So instead of mapping 1 to 1 to each production bug , we added/updated few end to end scenarios in these areas covering most of these issues path + few additional related validations.
This is working very well now as we are finding most of these bugs (if any) in regression test runs only. And automation is being considered very effective by business analysts as well. | Reported defects are not covered specifications, it is behaviour not anticipated. I would always add an automated test for each found defect, as it is probably is the brittle part of the application. It also documents the new expected behaviour.
Now what kind of test you write depends on the defect. Preferably you first write a failing test to reproduce the defect and then fix it. I would try to start reproducing it in a unit-test and slowly go up the pyramid if needed. |
38,645 | As currently, we are having coverage for P1 test cases for an end to end scenarios. We are following the test pyramid strategy. But now we are planning to cover the customer bugs. So just want to know whether we need to provide automation coverage for all bugs or not. | 2019/04/06 | [
"https://sqa.stackexchange.com/questions/38645",
"https://sqa.stackexchange.com",
"https://sqa.stackexchange.com/users/37975/"
] | Reported defects are not covered specifications, it is behaviour not anticipated. I would always add an automated test for each found defect, as it is probably is the brittle part of the application. It also documents the new expected behaviour.
Now what kind of test you write depends on the defect. Preferably you first write a failing test to reproduce the defect and then fix it. I would try to start reproducing it in a unit-test and slowly go up the pyramid if needed. | 1. My first question to you - what is your criteria for regression tests? How do you choose what to automate and what to not? I guess you don't have it, because it should answer your own question. It is not a problem to automate something, it is challenge **to automate the right test cases**. We learn from bugs raised by customers, but only in few cases we really need to automate them.
2. Since we cannot automate everything **typical** criteria for e2e is to automate
1) only standard features
2) high risk
3) most used
3. If you are living in agile world, I would suggest you to read a book "[Agile testing](https://agiletester.ca)" by Janet Gregory & Lisa Crispin. In their book they have several chapters on **Agile Quadrants** and chapter on **Test Automation Strategy**. They suggest to write e2e tests for epics, integration tests for stories and unit tests for tasks.
4. Another idea would be to take free training on [Test Automation Strategy](http://angiejones.tech/test-automation-strategy/) at [Test Automation University](https://testautomationu.applitools.com).
5. More test automation strategy modules, collected by Lisa Crispin you will find on [JoeColantonio](https://www.joecolantonio.com/modeling-automation-2/) website. |
38,645 | As currently, we are having coverage for P1 test cases for an end to end scenarios. We are following the test pyramid strategy. But now we are planning to cover the customer bugs. So just want to know whether we need to provide automation coverage for all bugs or not. | 2019/04/06 | [
"https://sqa.stackexchange.com/questions/38645",
"https://sqa.stackexchange.com",
"https://sqa.stackexchange.com/users/37975/"
] | Recently been in similar situation and after analysis found an interesting co- relation of bugs found.
>
> **The result of the analysis was bugs hide in clusters mostly in few
> specific areas only**.
>
>
>
In other words bugs are not scattered all across the application but mostly exist in clusters in few area only.
So instead of mapping 1 to 1 to each production bug , we added/updated few end to end scenarios in these areas covering most of these issues path + few additional related validations.
This is working very well now as we are finding most of these bugs (if any) in regression test runs only. And automation is being considered very effective by business analysts as well. | 1. My first question to you - what is your criteria for regression tests? How do you choose what to automate and what to not? I guess you don't have it, because it should answer your own question. It is not a problem to automate something, it is challenge **to automate the right test cases**. We learn from bugs raised by customers, but only in few cases we really need to automate them.
2. Since we cannot automate everything **typical** criteria for e2e is to automate
1) only standard features
2) high risk
3) most used
3. If you are living in agile world, I would suggest you to read a book "[Agile testing](https://agiletester.ca)" by Janet Gregory & Lisa Crispin. In their book they have several chapters on **Agile Quadrants** and chapter on **Test Automation Strategy**. They suggest to write e2e tests for epics, integration tests for stories and unit tests for tasks.
4. Another idea would be to take free training on [Test Automation Strategy](http://angiejones.tech/test-automation-strategy/) at [Test Automation University](https://testautomationu.applitools.com).
5. More test automation strategy modules, collected by Lisa Crispin you will find on [JoeColantonio](https://www.joecolantonio.com/modeling-automation-2/) website. |
91,211 | I'm suffering what seems to be a common ailment... Performance starts to really lag about 20-30 minutes into a fresh launch and file.
I've been researching this issue down to the nitty gritty for a while now, so I've plowed through the most common suggestion for sure.
==> I'm working with large and complex files utilizing a very wide range of illustrator effects, masks, plugins, distortions, 3d, blend modes... all at once, often at huge artboards! Multiple artboards! Embeded images! You name it, I'm doing it.
I've already had to significantly reel in my workflow and limit my filters (no gaussian blurs... no svg filters like drop shadow etc.) but the thing is, I really need to work in this way because I work with constant revisions on everything and the ability to change any piece on the fly is becoming both the glory and the horror that is illustrator.
I built my own custom Windows 10 machine last year, tailored to graphic design. I didn't buy the top end components at the time since I didn't have the money, but I've since upgraded a number of components and I'm hitting the ceiling in some areas. To buy stronger components in some areas I pretty much need to start at motherboard. sigh.
===> Windows 10 x64
32gb 2133 ddr4
X2 512 gb samsung SSD's (all my working files are on my boot SSD
Radeon R9 380 w/ 8gb (upgraded after crap performance from a GTX 970 2gb)
It's a shame because illustrator is an amazing tool. Combined with the set of plugins offered from Astute graphics, I have a very similar toolset to what photoshop can do. But in vector, it's very slow. | 2017/05/10 | [
"https://graphicdesign.stackexchange.com/questions/91211",
"https://graphicdesign.stackexchange.com",
"https://graphicdesign.stackexchange.com/users/94057/"
] | Just to chime in... yup.. AI can be dog slow and it has very little to do with actual hardware specs.
Best you can do is **utilize layers** well and **hide portions of artwork** you aren't directly working on. **Limiting raster effects** will help a great deal as well.
If you must use raster effects, set the **Document Raster Effects Settings** (Effects Menu) to 72ppi while working. It'll *greatly* speed up raster effect drawing. Then before output switch it back to 300ppi and wait for things to redraw.
There's really not much more you can do.
There's some super secret, internal limit to something that once a file passes that limit, it is often like walking through mud to get things done. Truth is, I'm not even certain the AI Dev teams knows what causes it (or they'd address it). | AI is traditionally slow with complex artwork and more so when plugins are added. Consider switching your workflow to design the piece in ID and link AI and PS assets externally. ID is good (and quick) when putting together many AI & PS files. Not sure it works in your case though.
Example: i am designing an 80+ page product catalogue in ID with 400+ AI & PSD links. This is typeset in 15 languages (as layers in the same ID file) and runs smoothly on a 4-yo laptop (slower hardware than what you have, ie win7/8gb/256ssd/4g video). |
25,530 | I can't pinpoint what I'm doing wrong while inflating my tubes. I use presta valves and have a "Joe Blow" Topeak pump. I put the tube stem at 12 o'clock, I unscrew the tip of the tube stem (but not too hard), press to let out some air, place the pump head on, lock it on, inflate to 120 psi (as recommended on the tire), then reverse all procedures, trying to keep everything straight (not wiggling the pump head too much).
I inflate before every ride but didn't think that was a problem as long as I'm letting some air out before pumping and am not inflating beyond the max. psi.
Still, after a couple weeks (riding about 3 times per week), the part of the tube stem that screws up and down is gone, and a few weeks later, after inflating, all the air rushes out when I take the pump off, then it won't hold air again.
The last time I replaced a tube for this reason, I decided to keep the little nut in place at the base of the stem near the tire (though my mechanic says it's unnecessary) and to keep the dust cap on the stem. I'm thinking these two items might not be necessary to most folks, but they'll perhaps protect against whatever I'm doing wrong.
Any other advice? | 2014/11/07 | [
"https://bicycles.stackexchange.com/questions/25530",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/14360/"
] | I also use a Joe Blow on my prestas. After I had a couple valve stems bend and/or break, I started making sure I only unscrew the stem a *little* bit. My theory was that by unscrewing the stem all the way up, it was easier to bend or break when pulling the pump head off. Haven't had it happen again since. | The retaining nut will help keep the valve in one position, which might solve a part of the problem. As for the cap, I don't think it's necessary - it will only protect the valve from weather conditions and dirt.
With a shop pump like Joe Blow a bit more reliable option is to place the valve at 6 o'clock position for pumping. When it's at 12 o'clock the hose comming from the bottom might exert some force on the valve stem bending it slightly every time you pump the tire.
Personally I've only broken the valve stem a few times and it was only because of wobbling around the pump (a compact hand pump) when removing it. I use retaining nuts, but I don't put caps on the valves, and haven't had any problems for the past 2 years. |
25,530 | I can't pinpoint what I'm doing wrong while inflating my tubes. I use presta valves and have a "Joe Blow" Topeak pump. I put the tube stem at 12 o'clock, I unscrew the tip of the tube stem (but not too hard), press to let out some air, place the pump head on, lock it on, inflate to 120 psi (as recommended on the tire), then reverse all procedures, trying to keep everything straight (not wiggling the pump head too much).
I inflate before every ride but didn't think that was a problem as long as I'm letting some air out before pumping and am not inflating beyond the max. psi.
Still, after a couple weeks (riding about 3 times per week), the part of the tube stem that screws up and down is gone, and a few weeks later, after inflating, all the air rushes out when I take the pump off, then it won't hold air again.
The last time I replaced a tube for this reason, I decided to keep the little nut in place at the base of the stem near the tire (though my mechanic says it's unnecessary) and to keep the dust cap on the stem. I'm thinking these two items might not be necessary to most folks, but they'll perhaps protect against whatever I'm doing wrong.
Any other advice? | 2014/11/07 | [
"https://bicycles.stackexchange.com/questions/25530",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/14360/"
] | I also use a Joe Blow on my prestas. After I had a couple valve stems bend and/or break, I started making sure I only unscrew the stem a *little* bit. My theory was that by unscrewing the stem all the way up, it was easier to bend or break when pulling the pump head off. Haven't had it happen again since. | A long term solution to this problem is to replace your presta valve tubes with schraders. I've broken too many presta valves (and never broken a schrader) to ever have faith in the prestas again. |
25,530 | I can't pinpoint what I'm doing wrong while inflating my tubes. I use presta valves and have a "Joe Blow" Topeak pump. I put the tube stem at 12 o'clock, I unscrew the tip of the tube stem (but not too hard), press to let out some air, place the pump head on, lock it on, inflate to 120 psi (as recommended on the tire), then reverse all procedures, trying to keep everything straight (not wiggling the pump head too much).
I inflate before every ride but didn't think that was a problem as long as I'm letting some air out before pumping and am not inflating beyond the max. psi.
Still, after a couple weeks (riding about 3 times per week), the part of the tube stem that screws up and down is gone, and a few weeks later, after inflating, all the air rushes out when I take the pump off, then it won't hold air again.
The last time I replaced a tube for this reason, I decided to keep the little nut in place at the base of the stem near the tire (though my mechanic says it's unnecessary) and to keep the dust cap on the stem. I'm thinking these two items might not be necessary to most folks, but they'll perhaps protect against whatever I'm doing wrong.
Any other advice? | 2014/11/07 | [
"https://bicycles.stackexchange.com/questions/25530",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/14360/"
] | Use those two items - retaining screw and cap.
On the valve there are actually two sets of threads
* One to open and close
* Two to remove the core
If you unscrew to far / hard the core comes out.
You probable loosened the core and then it blew out.
Some sets of tubes just don't have the core very tight.
Get a tool to remove the core - it is also used to tighten it.
Tighten the core.
I even use a dab of locktite but don't get it in the rubber mechanism.
Some tubes do not have serviceable cores (won't come out).
You would probably be better off with those type of tubes.
When I get a flat I save the core, retaining nut, and cap so I have spares. | The retaining nut will help keep the valve in one position, which might solve a part of the problem. As for the cap, I don't think it's necessary - it will only protect the valve from weather conditions and dirt.
With a shop pump like Joe Blow a bit more reliable option is to place the valve at 6 o'clock position for pumping. When it's at 12 o'clock the hose comming from the bottom might exert some force on the valve stem bending it slightly every time you pump the tire.
Personally I've only broken the valve stem a few times and it was only because of wobbling around the pump (a compact hand pump) when removing it. I use retaining nuts, but I don't put caps on the valves, and haven't had any problems for the past 2 years. |
25,530 | I can't pinpoint what I'm doing wrong while inflating my tubes. I use presta valves and have a "Joe Blow" Topeak pump. I put the tube stem at 12 o'clock, I unscrew the tip of the tube stem (but not too hard), press to let out some air, place the pump head on, lock it on, inflate to 120 psi (as recommended on the tire), then reverse all procedures, trying to keep everything straight (not wiggling the pump head too much).
I inflate before every ride but didn't think that was a problem as long as I'm letting some air out before pumping and am not inflating beyond the max. psi.
Still, after a couple weeks (riding about 3 times per week), the part of the tube stem that screws up and down is gone, and a few weeks later, after inflating, all the air rushes out when I take the pump off, then it won't hold air again.
The last time I replaced a tube for this reason, I decided to keep the little nut in place at the base of the stem near the tire (though my mechanic says it's unnecessary) and to keep the dust cap on the stem. I'm thinking these two items might not be necessary to most folks, but they'll perhaps protect against whatever I'm doing wrong.
Any other advice? | 2014/11/07 | [
"https://bicycles.stackexchange.com/questions/25530",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/14360/"
] | Use those two items - retaining screw and cap.
On the valve there are actually two sets of threads
* One to open and close
* Two to remove the core
If you unscrew to far / hard the core comes out.
You probable loosened the core and then it blew out.
Some sets of tubes just don't have the core very tight.
Get a tool to remove the core - it is also used to tighten it.
Tighten the core.
I even use a dab of locktite but don't get it in the rubber mechanism.
Some tubes do not have serviceable cores (won't come out).
You would probably be better off with those type of tubes.
When I get a flat I save the core, retaining nut, and cap so I have spares. | A long term solution to this problem is to replace your presta valve tubes with schraders. I've broken too many presta valves (and never broken a schrader) to ever have faith in the prestas again. |
25,530 | I can't pinpoint what I'm doing wrong while inflating my tubes. I use presta valves and have a "Joe Blow" Topeak pump. I put the tube stem at 12 o'clock, I unscrew the tip of the tube stem (but not too hard), press to let out some air, place the pump head on, lock it on, inflate to 120 psi (as recommended on the tire), then reverse all procedures, trying to keep everything straight (not wiggling the pump head too much).
I inflate before every ride but didn't think that was a problem as long as I'm letting some air out before pumping and am not inflating beyond the max. psi.
Still, after a couple weeks (riding about 3 times per week), the part of the tube stem that screws up and down is gone, and a few weeks later, after inflating, all the air rushes out when I take the pump off, then it won't hold air again.
The last time I replaced a tube for this reason, I decided to keep the little nut in place at the base of the stem near the tire (though my mechanic says it's unnecessary) and to keep the dust cap on the stem. I'm thinking these two items might not be necessary to most folks, but they'll perhaps protect against whatever I'm doing wrong.
Any other advice? | 2014/11/07 | [
"https://bicycles.stackexchange.com/questions/25530",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/14360/"
] | The retaining nut will help keep the valve in one position, which might solve a part of the problem. As for the cap, I don't think it's necessary - it will only protect the valve from weather conditions and dirt.
With a shop pump like Joe Blow a bit more reliable option is to place the valve at 6 o'clock position for pumping. When it's at 12 o'clock the hose comming from the bottom might exert some force on the valve stem bending it slightly every time you pump the tire.
Personally I've only broken the valve stem a few times and it was only because of wobbling around the pump (a compact hand pump) when removing it. I use retaining nuts, but I don't put caps on the valves, and haven't had any problems for the past 2 years. | A long term solution to this problem is to replace your presta valve tubes with schraders. I've broken too many presta valves (and never broken a schrader) to ever have faith in the prestas again. |
154,066 | When we talk about the linear regression, we have $R^2$ to measure the goodness of fit of the linear model.
Here is the problem, do we have a similar statistical measure to assess the goodness of fit of a GARCH model for the raw data? | 2015/05/26 | [
"https://stats.stackexchange.com/questions/154066",
"https://stats.stackexchange.com",
"https://stats.stackexchange.com/users/48519/"
] | A GARCH model assumes a perfect fit for the conditional variance equation. This feature is due the definition/construction of the GARCH model (note that there is no error term in the conditional variance equation in a GARCH model).
A class of conditional variance models that allows for imperfect fit are stochastic volatility models.
In any case, measuring the goodness of fit of conditional variance models is problematic -- because the conditional variance is unobserved. Thus conventional techniques such as running a regression of the dependent variable (the conditional variance) on the regressors (e.g. lagged conditional variances and lagged squared error terms) and taking the $R^2$ as a measure of fit do not work.
You can assess how "good" a GARCH model is by looking at model residuals and checking how well they match the model assumptions. Normally you assume the residuals to be i.i.d. You also assume they follow a certain distribution, e.g. a normal distribution. You use this assumption in constructing the likelihood function which is then used for fitting the model via the maximum likelihood estimation (MLE). Thus you could look at the residuals and see how close they are to being i.i.d. and following the assumed distribution.
Aksakal suggested looking at AIC or BIC which gives you model likelihood adjusted for the number of parameters (so as to penalize for overfitting). Looking at model likelihood itself can also be meaningful, but then you have to keep in mind that richer models normally yield higher likelihoods. | GARCH and many other time series models are estimated using maximum likelihood methods (MLE). The common measure of in-sample fit is the information criterion such as Akaike (AIC) or Bayesian (BIC). These are computed using the loglikelihoods.
I sometimes use [FVU](http://en.wikipedia.org/wiki/Fraction_of_variance_unexplained), which may feel more familiar to you if you're used to $R^2$. Its problem is that it doesn't account for parsimony though, that's why it's my last resort tool when AIC is not applicable |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | **Crowbar and Axe**
are the best frends of any scavenger. You can wear them both and they both are not bad weapons and have a lot of different usages. + knife - you shuold always have a knife of some sort with you in any kind of hiking even now. | If you are going to scavenge, you don't know what you may find that is valuable. So you must be ready for a lot of different situations. You would probably need enough tools that carrying them in a backpack would not be viable.
I can think of:
Tool box
--------
[](https://i.stack.imgur.com/mybbW.jpg)
Because it would absolutely suck that you can't get to the treasure inside the vault for want of a 1/8" phillips screwdriver.
Swiss Army Knife
----------------
[](https://i.stack.imgur.com/fs7wL.jpg)
Opening and closing the toolbox all the time sucks. With this you can pick your teeth, cut a rope and open a can in a very practical way.
Survival Shotgun
----------------
[](https://i.stack.imgur.com/3onXv.png)
This guy carries a mini-tent, food and water in the butt [of his shotgun](https://www.instructables.com/id/How-to-Build-the-Ultimate-Survival-Shotgun/). He also carries condoms and a blanket there (seriously, go check).
Cart
----
[](https://i.stack.imgur.com/zp8ZD.jpg)
You will want to bring that bounty home, right? Also helps carrying tools.
Doggo
-----
[](https://i.stack.imgur.com/0f9Ym.jpg)
A hunting companion that is also a friend and living alarm. Can also be trained to pull the cart and to find specific kinds of goods in the wastelands. Doubles as food when you run out of other edibles.
Teddy bear
----------
[](https://i.stack.imgur.com/n8Vt9.jpg)
Isolation can drive you mad. It's always nice to have someone to talk to, and the bear is more articulate than the dog when you eat the right pills. Also you've probably already eaten the dog. |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | [**Clockwork hacksaw.**](http://www.drlindseyfitzharris.com/2010/09/23/the-chirurgeons-box-the-clockwork-saw/)
From a postapocalyptic character I dreamed up for this question, who sabotages a helicopter.
[Primitive tribe fighting back against advanced military force?](https://worldbuilding.stackexchange.com/questions/110571/primitive-tribe-fighting-back-against-advanced-military-force)
>
> I was thinking about Hack's homemade hacksaw. It has a clockspring at
> the base she can wind up. On triggering it moves the blade back and
> forth a couple of mm, very fast.
>
>
>
Her hacksaw converges on a bone saw. A good metal scavenging tool which is why she carries it. Vibration amplitude can be adjusted depending on what she is cutting. For metal or bone minimal amplitude and maximum vibrations. For flesh, the opposite.
---
**Bow.**
Not too creative, but lightweight and versatile. You can shoot a light line and use it to pull up a heavy line that you can climb. You can launch flame arrows into dark spaces to light them up without going in and getting bitten. You can hunt. You can fight. You can make your own ammo. You can retrieve and reuse your ammo.
---
**Lobos.**
This is from World War Z - Lobo is short for "lobotomizer" and was a tool/weapon made (actually mass produced - 23 million of them) from the frames of cars. For a postapocalyptic fiction I like a thing that shows its provenance. I picture the lobos as being recognizably pieces of car frame, modified in a standard way. For your characters I imagine them as hybrid quarterstaff / crowbars. And they can be thrown like a javelin.
---
**Blast bottles.**
These are plastic bottles full of homemade gunpowder. Gunpowder can be made with primitive tech and plastic bottles would be great for keeping it dry and contained. Your demolitions character only uses Mountain Dew bottles, for her own reasons. Blast bottles can be used to open doors and dislodge things. Or you can wrap one with a chain, light it and throw it as a grenade. | If you are going to scavenge, you don't know what you may find that is valuable. So you must be ready for a lot of different situations. You would probably need enough tools that carrying them in a backpack would not be viable.
I can think of:
Tool box
--------
[](https://i.stack.imgur.com/mybbW.jpg)
Because it would absolutely suck that you can't get to the treasure inside the vault for want of a 1/8" phillips screwdriver.
Swiss Army Knife
----------------
[](https://i.stack.imgur.com/fs7wL.jpg)
Opening and closing the toolbox all the time sucks. With this you can pick your teeth, cut a rope and open a can in a very practical way.
Survival Shotgun
----------------
[](https://i.stack.imgur.com/3onXv.png)
This guy carries a mini-tent, food and water in the butt [of his shotgun](https://www.instructables.com/id/How-to-Build-the-Ultimate-Survival-Shotgun/). He also carries condoms and a blanket there (seriously, go check).
Cart
----
[](https://i.stack.imgur.com/zp8ZD.jpg)
You will want to bring that bounty home, right? Also helps carrying tools.
Doggo
-----
[](https://i.stack.imgur.com/0f9Ym.jpg)
A hunting companion that is also a friend and living alarm. Can also be trained to pull the cart and to find specific kinds of goods in the wastelands. Doubles as food when you run out of other edibles.
Teddy bear
----------
[](https://i.stack.imgur.com/n8Vt9.jpg)
Isolation can drive you mad. It's always nice to have someone to talk to, and the bear is more articulate than the dog when you eat the right pills. Also you've probably already eaten the dog. |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | [**Clockwork hacksaw.**](http://www.drlindseyfitzharris.com/2010/09/23/the-chirurgeons-box-the-clockwork-saw/)
From a postapocalyptic character I dreamed up for this question, who sabotages a helicopter.
[Primitive tribe fighting back against advanced military force?](https://worldbuilding.stackexchange.com/questions/110571/primitive-tribe-fighting-back-against-advanced-military-force)
>
> I was thinking about Hack's homemade hacksaw. It has a clockspring at
> the base she can wind up. On triggering it moves the blade back and
> forth a couple of mm, very fast.
>
>
>
Her hacksaw converges on a bone saw. A good metal scavenging tool which is why she carries it. Vibration amplitude can be adjusted depending on what she is cutting. For metal or bone minimal amplitude and maximum vibrations. For flesh, the opposite.
---
**Bow.**
Not too creative, but lightweight and versatile. You can shoot a light line and use it to pull up a heavy line that you can climb. You can launch flame arrows into dark spaces to light them up without going in and getting bitten. You can hunt. You can fight. You can make your own ammo. You can retrieve and reuse your ammo.
---
**Lobos.**
This is from World War Z - Lobo is short for "lobotomizer" and was a tool/weapon made (actually mass produced - 23 million of them) from the frames of cars. For a postapocalyptic fiction I like a thing that shows its provenance. I picture the lobos as being recognizably pieces of car frame, modified in a standard way. For your characters I imagine them as hybrid quarterstaff / crowbars. And they can be thrown like a javelin.
---
**Blast bottles.**
These are plastic bottles full of homemade gunpowder. Gunpowder can be made with primitive tech and plastic bottles would be great for keeping it dry and contained. Your demolitions character only uses Mountain Dew bottles, for her own reasons. Blast bottles can be used to open doors and dislodge things. Or you can wrap one with a chain, light it and throw it as a grenade. | **Crowbar and Axe**
are the best frends of any scavenger. You can wear them both and they both are not bad weapons and have a lot of different usages. + knife - you shuold always have a knife of some sort with you in any kind of hiking even now. |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | Forget the crowbar, get a halligan bar.
---------------------------------------
Scavengers are less like burglars and more like firefighters they just want entry as easily as possible, so look at what fire fighters and other rescue units use.
[](https://i.stack.imgur.com/l7DtW.gif)
[halligan bars](https://en.wikipedia.org/wiki/Halligan_bar) are far more versatile than a crowbar and way better for getting through doors and walls. They were designed by firefighters to get into buildings *fast* without carrying a lot of gear. the metal cutting claw variety (see below) will break padlocks and tear open steel doors. So for entry with the minimum of additional tools it is perfect. It is the standard tool for forced entry, even the military often uses them. It does everything a crowbar does and a lot more. There is nearly nothing it can't be used to enter, especially if you have time. Since a wide variety of them exist, there is even believable a real ornate one actually exists your character could have found, firefighters sometimes give ornate axes as awards/memorabilia after all.
[](https://i.stack.imgur.com/iAm1E.jpg)
The other thing you need is a **good backpack**, you have to carry whatever you find afterall.
A **light source** because abandoned places are dark, especially the areas in which anything is likely to still be valuable, head mounted for preference.
but the best thing they could have is **a partner**, anyone who does demolition, fire, or rescue can tell you a compromised building is very dangerous. spend too much time in them by yourself and your luck will run out. Without aid you are just another corpse in the rubble. | **A War Pick and Rope**
A War pick is essentially 1 side of a Pickaxe and 1 side of a hammer/axe.
The pick side combines the advantages of a standard pick and crow bar. You can use it to help climb buildings, by stabbing the pick side into the wall. You can use it to destroy stones, rocks or metal contractions in your way. The metal pick will provide much greater penetration that a crow bar or axe and doubles up as an excellent weapon. You can also jam it into all sorts of cracks and use the war pick to leverage something out just as you would with a crow bar.
The other side can basically be a hammer or axe, depending on your needs. An axe would be good for cutting things, a hammer would be good for building things. Either way, I would say this part is more of a style/situation choice for you to make.
The next part is the rope. Rope is pretty damn important when spelunking or scavenging. Due to the war picks shape, you can use it as a grappling hook, by tying the rope to it,swinging it then throwing it. You would also use your pick as a ranged weapon, swinging and throwing it at opponents then pulling it back. Finally, you could use the rope to allow multiple people to apply force to the pick, so if you have a particularly stuck door, jam the pick in there, tie the rope to the pick and have your friends help you pull away.
Bonus features
* The head of the War pick could be detachable like some styles of hammers or axes. This means you can change the shaft length to make it easier to apply more force or use as a grappling hook.
* It can double up as a cane if the shaft is long enough |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | Forget the crowbar, get a halligan bar.
---------------------------------------
Scavengers are less like burglars and more like firefighters they just want entry as easily as possible, so look at what fire fighters and other rescue units use.
[](https://i.stack.imgur.com/l7DtW.gif)
[halligan bars](https://en.wikipedia.org/wiki/Halligan_bar) are far more versatile than a crowbar and way better for getting through doors and walls. They were designed by firefighters to get into buildings *fast* without carrying a lot of gear. the metal cutting claw variety (see below) will break padlocks and tear open steel doors. So for entry with the minimum of additional tools it is perfect. It is the standard tool for forced entry, even the military often uses them. It does everything a crowbar does and a lot more. There is nearly nothing it can't be used to enter, especially if you have time. Since a wide variety of them exist, there is even believable a real ornate one actually exists your character could have found, firefighters sometimes give ornate axes as awards/memorabilia after all.
[](https://i.stack.imgur.com/iAm1E.jpg)
The other thing you need is a **good backpack**, you have to carry whatever you find afterall.
A **light source** because abandoned places are dark, especially the areas in which anything is likely to still be valuable, head mounted for preference.
but the best thing they could have is **a partner**, anyone who does demolition, fire, or rescue can tell you a compromised building is very dangerous. spend too much time in them by yourself and your luck will run out. Without aid you are just another corpse in the rubble. | **Crowbar and Axe**
are the best frends of any scavenger. You can wear them both and they both are not bad weapons and have a lot of different usages. + knife - you shuold always have a knife of some sort with you in any kind of hiking even now. |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | [**Clockwork hacksaw.**](http://www.drlindseyfitzharris.com/2010/09/23/the-chirurgeons-box-the-clockwork-saw/)
From a postapocalyptic character I dreamed up for this question, who sabotages a helicopter.
[Primitive tribe fighting back against advanced military force?](https://worldbuilding.stackexchange.com/questions/110571/primitive-tribe-fighting-back-against-advanced-military-force)
>
> I was thinking about Hack's homemade hacksaw. It has a clockspring at
> the base she can wind up. On triggering it moves the blade back and
> forth a couple of mm, very fast.
>
>
>
Her hacksaw converges on a bone saw. A good metal scavenging tool which is why she carries it. Vibration amplitude can be adjusted depending on what she is cutting. For metal or bone minimal amplitude and maximum vibrations. For flesh, the opposite.
---
**Bow.**
Not too creative, but lightweight and versatile. You can shoot a light line and use it to pull up a heavy line that you can climb. You can launch flame arrows into dark spaces to light them up without going in and getting bitten. You can hunt. You can fight. You can make your own ammo. You can retrieve and reuse your ammo.
---
**Lobos.**
This is from World War Z - Lobo is short for "lobotomizer" and was a tool/weapon made (actually mass produced - 23 million of them) from the frames of cars. For a postapocalyptic fiction I like a thing that shows its provenance. I picture the lobos as being recognizably pieces of car frame, modified in a standard way. For your characters I imagine them as hybrid quarterstaff / crowbars. And they can be thrown like a javelin.
---
**Blast bottles.**
These are plastic bottles full of homemade gunpowder. Gunpowder can be made with primitive tech and plastic bottles would be great for keeping it dry and contained. Your demolitions character only uses Mountain Dew bottles, for her own reasons. Blast bottles can be used to open doors and dislodge things. Or you can wrap one with a chain, light it and throw it as a grenade. | Tomahawks
A proper tomahawk has a hatchet blade counter-balanced by a small hammer surface on the back of the head. A steel tomahawk whose axe blade has a pointed beard (the part sticking down from the main axe blade) can also be used for prying.
In one tool, you have a weapon, a hammer, an axe, a prybar, a skinning blade (hold the hawk by the hammer surface to scrape skin from a kill and then to scrape clinging meat from the hide), and a climbing aid (can dig the axe into wood to make the handle a hand-hold or use the beard to hook a ledge too high for you to reach. |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | Tomahawks
A proper tomahawk has a hatchet blade counter-balanced by a small hammer surface on the back of the head. A steel tomahawk whose axe blade has a pointed beard (the part sticking down from the main axe blade) can also be used for prying.
In one tool, you have a weapon, a hammer, an axe, a prybar, a skinning blade (hold the hawk by the hammer surface to scrape skin from a kill and then to scrape clinging meat from the hide), and a climbing aid (can dig the axe into wood to make the handle a hand-hold or use the beard to hook a ledge too high for you to reach. | **A War Pick and Rope**
A War pick is essentially 1 side of a Pickaxe and 1 side of a hammer/axe.
The pick side combines the advantages of a standard pick and crow bar. You can use it to help climb buildings, by stabbing the pick side into the wall. You can use it to destroy stones, rocks or metal contractions in your way. The metal pick will provide much greater penetration that a crow bar or axe and doubles up as an excellent weapon. You can also jam it into all sorts of cracks and use the war pick to leverage something out just as you would with a crow bar.
The other side can basically be a hammer or axe, depending on your needs. An axe would be good for cutting things, a hammer would be good for building things. Either way, I would say this part is more of a style/situation choice for you to make.
The next part is the rope. Rope is pretty damn important when spelunking or scavenging. Due to the war picks shape, you can use it as a grappling hook, by tying the rope to it,swinging it then throwing it. You would also use your pick as a ranged weapon, swinging and throwing it at opponents then pulling it back. Finally, you could use the rope to allow multiple people to apply force to the pick, so if you have a particularly stuck door, jam the pick in there, tie the rope to the pick and have your friends help you pull away.
Bonus features
* The head of the War pick could be detachable like some styles of hammers or axes. This means you can change the shaft length to make it easier to apply more force or use as a grappling hook.
* It can double up as a cane if the shaft is long enough |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | [**Clockwork hacksaw.**](http://www.drlindseyfitzharris.com/2010/09/23/the-chirurgeons-box-the-clockwork-saw/)
From a postapocalyptic character I dreamed up for this question, who sabotages a helicopter.
[Primitive tribe fighting back against advanced military force?](https://worldbuilding.stackexchange.com/questions/110571/primitive-tribe-fighting-back-against-advanced-military-force)
>
> I was thinking about Hack's homemade hacksaw. It has a clockspring at
> the base she can wind up. On triggering it moves the blade back and
> forth a couple of mm, very fast.
>
>
>
Her hacksaw converges on a bone saw. A good metal scavenging tool which is why she carries it. Vibration amplitude can be adjusted depending on what she is cutting. For metal or bone minimal amplitude and maximum vibrations. For flesh, the opposite.
---
**Bow.**
Not too creative, but lightweight and versatile. You can shoot a light line and use it to pull up a heavy line that you can climb. You can launch flame arrows into dark spaces to light them up without going in and getting bitten. You can hunt. You can fight. You can make your own ammo. You can retrieve and reuse your ammo.
---
**Lobos.**
This is from World War Z - Lobo is short for "lobotomizer" and was a tool/weapon made (actually mass produced - 23 million of them) from the frames of cars. For a postapocalyptic fiction I like a thing that shows its provenance. I picture the lobos as being recognizably pieces of car frame, modified in a standard way. For your characters I imagine them as hybrid quarterstaff / crowbars. And they can be thrown like a javelin.
---
**Blast bottles.**
These are plastic bottles full of homemade gunpowder. Gunpowder can be made with primitive tech and plastic bottles would be great for keeping it dry and contained. Your demolitions character only uses Mountain Dew bottles, for her own reasons. Blast bottles can be used to open doors and dislodge things. Or you can wrap one with a chain, light it and throw it as a grenade. | Forget the crowbar, get a halligan bar.
---------------------------------------
Scavengers are less like burglars and more like firefighters they just want entry as easily as possible, so look at what fire fighters and other rescue units use.
[](https://i.stack.imgur.com/l7DtW.gif)
[halligan bars](https://en.wikipedia.org/wiki/Halligan_bar) are far more versatile than a crowbar and way better for getting through doors and walls. They were designed by firefighters to get into buildings *fast* without carrying a lot of gear. the metal cutting claw variety (see below) will break padlocks and tear open steel doors. So for entry with the minimum of additional tools it is perfect. It is the standard tool for forced entry, even the military often uses them. It does everything a crowbar does and a lot more. There is nearly nothing it can't be used to enter, especially if you have time. Since a wide variety of them exist, there is even believable a real ornate one actually exists your character could have found, firefighters sometimes give ornate axes as awards/memorabilia after all.
[](https://i.stack.imgur.com/iAm1E.jpg)
The other thing you need is a **good backpack**, you have to carry whatever you find afterall.
A **light source** because abandoned places are dark, especially the areas in which anything is likely to still be valuable, head mounted for preference.
but the best thing they could have is **a partner**, anyone who does demolition, fire, or rescue can tell you a compromised building is very dangerous. spend too much time in them by yourself and your luck will run out. Without aid you are just another corpse in the rubble. |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | [**Clockwork hacksaw.**](http://www.drlindseyfitzharris.com/2010/09/23/the-chirurgeons-box-the-clockwork-saw/)
From a postapocalyptic character I dreamed up for this question, who sabotages a helicopter.
[Primitive tribe fighting back against advanced military force?](https://worldbuilding.stackexchange.com/questions/110571/primitive-tribe-fighting-back-against-advanced-military-force)
>
> I was thinking about Hack's homemade hacksaw. It has a clockspring at
> the base she can wind up. On triggering it moves the blade back and
> forth a couple of mm, very fast.
>
>
>
Her hacksaw converges on a bone saw. A good metal scavenging tool which is why she carries it. Vibration amplitude can be adjusted depending on what she is cutting. For metal or bone minimal amplitude and maximum vibrations. For flesh, the opposite.
---
**Bow.**
Not too creative, but lightweight and versatile. You can shoot a light line and use it to pull up a heavy line that you can climb. You can launch flame arrows into dark spaces to light them up without going in and getting bitten. You can hunt. You can fight. You can make your own ammo. You can retrieve and reuse your ammo.
---
**Lobos.**
This is from World War Z - Lobo is short for "lobotomizer" and was a tool/weapon made (actually mass produced - 23 million of them) from the frames of cars. For a postapocalyptic fiction I like a thing that shows its provenance. I picture the lobos as being recognizably pieces of car frame, modified in a standard way. For your characters I imagine them as hybrid quarterstaff / crowbars. And they can be thrown like a javelin.
---
**Blast bottles.**
These are plastic bottles full of homemade gunpowder. Gunpowder can be made with primitive tech and plastic bottles would be great for keeping it dry and contained. Your demolitions character only uses Mountain Dew bottles, for her own reasons. Blast bottles can be used to open doors and dislodge things. Or you can wrap one with a chain, light it and throw it as a grenade. | **A War Pick and Rope**
A War pick is essentially 1 side of a Pickaxe and 1 side of a hammer/axe.
The pick side combines the advantages of a standard pick and crow bar. You can use it to help climb buildings, by stabbing the pick side into the wall. You can use it to destroy stones, rocks or metal contractions in your way. The metal pick will provide much greater penetration that a crow bar or axe and doubles up as an excellent weapon. You can also jam it into all sorts of cracks and use the war pick to leverage something out just as you would with a crow bar.
The other side can basically be a hammer or axe, depending on your needs. An axe would be good for cutting things, a hammer would be good for building things. Either way, I would say this part is more of a style/situation choice for you to make.
The next part is the rope. Rope is pretty damn important when spelunking or scavenging. Due to the war picks shape, you can use it as a grappling hook, by tying the rope to it,swinging it then throwing it. You would also use your pick as a ranged weapon, swinging and throwing it at opponents then pulling it back. Finally, you could use the rope to allow multiple people to apply force to the pick, so if you have a particularly stuck door, jam the pick in there, tie the rope to the pick and have your friends help you pull away.
Bonus features
* The head of the War pick could be detachable like some styles of hammers or axes. This means you can change the shaft length to make it easier to apply more force or use as a grappling hook.
* It can double up as a cane if the shaft is long enough |
154,352 | In my world the „apocalypse“ dates back several decades and most people have settled down, the s**cavenging is left to professional adventurers** who roam the less accessible and more dangerous ruins of a destroyed metropolis.
I want to equip those adventurers with **useful tools for scavenging** while **limiting the the equipment** to the most important things to keep it **as lightweight as possible** and enable a character **to work with the things he can actually carry on his body** (walking back to one's vehicle several times just to produce everything he needs doesn't work for a film or game).
(Some of) the tools should enable the user to **defend themselves without carrying additional weapons** against attacks from wild animals or primitive tribes (in fact many weapons originated from tools).
Advantage:
Compared to present-day burglars the scavengers don't have to be as careful - instead of carrying tools for lock picking one could simply knock down the front door.
Consider:
Fuel, gas (actual gas) and electricity are quite rare although who could rather come into possession of fuel and gas than the very people who scavenge the old world's remains...
---
The very question is:
**What are indispensable tools for professional scavenging?**
=============================================================
(Such as climbing walls, roping, prying doors or safes or walls and making ones way throught the debris.)
**Please additionally state, which other tools your suggestion would render redundand**
(e. g. carrying a crowbar there is no need for an additional welding torch or sledgehammer)
and **if it could be used (or modified) as a weapon**.
---
---
My ideas so far:
----------------
* My main scavenger character carries a decorated **crowbar**, upside
down, like a gentleman's cane. He is obsessed with ancient
civilization he encounters on his raids every day. It can be used in
battle like a *crow's beak*/warhammer, hooking hostile's legs to make
them fall and as a pickaxe for climbing.
* a small **welding torch** (that can be turned into a
flamethrower by turning a switch to bypass the gas into an additional cartridge for inflammable liquids to spray those instead of burning the gas directly).
* a **grappling hook** (for climbing/roping and swung as weapon to get a hold of enemies during battle) | 2019/09/02 | [
"https://worldbuilding.stackexchange.com/questions/154352",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/67222/"
] | Forget the crowbar, get a halligan bar.
---------------------------------------
Scavengers are less like burglars and more like firefighters they just want entry as easily as possible, so look at what fire fighters and other rescue units use.
[](https://i.stack.imgur.com/l7DtW.gif)
[halligan bars](https://en.wikipedia.org/wiki/Halligan_bar) are far more versatile than a crowbar and way better for getting through doors and walls. They were designed by firefighters to get into buildings *fast* without carrying a lot of gear. the metal cutting claw variety (see below) will break padlocks and tear open steel doors. So for entry with the minimum of additional tools it is perfect. It is the standard tool for forced entry, even the military often uses them. It does everything a crowbar does and a lot more. There is nearly nothing it can't be used to enter, especially if you have time. Since a wide variety of them exist, there is even believable a real ornate one actually exists your character could have found, firefighters sometimes give ornate axes as awards/memorabilia after all.
[](https://i.stack.imgur.com/iAm1E.jpg)
The other thing you need is a **good backpack**, you have to carry whatever you find afterall.
A **light source** because abandoned places are dark, especially the areas in which anything is likely to still be valuable, head mounted for preference.
but the best thing they could have is **a partner**, anyone who does demolition, fire, or rescue can tell you a compromised building is very dangerous. spend too much time in them by yourself and your luck will run out. Without aid you are just another corpse in the rubble. | If you are going to scavenge, you don't know what you may find that is valuable. So you must be ready for a lot of different situations. You would probably need enough tools that carrying them in a backpack would not be viable.
I can think of:
Tool box
--------
[](https://i.stack.imgur.com/mybbW.jpg)
Because it would absolutely suck that you can't get to the treasure inside the vault for want of a 1/8" phillips screwdriver.
Swiss Army Knife
----------------
[](https://i.stack.imgur.com/fs7wL.jpg)
Opening and closing the toolbox all the time sucks. With this you can pick your teeth, cut a rope and open a can in a very practical way.
Survival Shotgun
----------------
[](https://i.stack.imgur.com/3onXv.png)
This guy carries a mini-tent, food and water in the butt [of his shotgun](https://www.instructables.com/id/How-to-Build-the-Ultimate-Survival-Shotgun/). He also carries condoms and a blanket there (seriously, go check).
Cart
----
[](https://i.stack.imgur.com/zp8ZD.jpg)
You will want to bring that bounty home, right? Also helps carrying tools.
Doggo
-----
[](https://i.stack.imgur.com/0f9Ym.jpg)
A hunting companion that is also a friend and living alarm. Can also be trained to pull the cart and to find specific kinds of goods in the wastelands. Doubles as food when you run out of other edibles.
Teddy bear
----------
[](https://i.stack.imgur.com/n8Vt9.jpg)
Isolation can drive you mad. It's always nice to have someone to talk to, and the bear is more articulate than the dog when you eat the right pills. Also you've probably already eaten the dog. |
120,952 | ### My previous employer wants me to fix a bug in the code I wrote while I was working for them. Should I provide assistance to them—on contract (paid) or for free—despite the fact I am no longer working for them?
**Background:**
Last summer I worked as an intern for a large manufacturing company. The duration of my contract was fixed to 3 months. I was paid an hourly rate for my work. My job responsibilities entailed IT support and software development. The software project that I worked on was a fairly simple server application. I worked on the project exclusively. Initially the project seemed to be a success, the software was working as intended. Before my contract concluded and I left the company, I made sure to leave extensive documentation on how to use the program and how to edit the source code should they need to.
I did not sign a contract specifically pertaining to this software project and any post deployment assistance it may require.
Since then I have started working for a different company as a full-time software developer in a different country.
**Problem:**
I have recently been contacted by my previous employer (this is over a year after my contract ended with them), saying that there is a small bug with the software that I previously wrote, and that they need my help to fix said problem. As previously mentioned I now work full-time in a different country. This means that going back there in person is out of the question. Though I do believe it will be possible to fix the bug remotely. If I were to help fix this bug it would require me to devote my free time (evenings/weekends) to assist them.
It is in my best interest to fix this bug so that I can still use the previous employer as a reference for future employment. I do not want them to be on bad terms with me.
**Question:**
Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time? Or should I provide the assistance for free since it is my moral responsibility, even though I am not contractually obligated to?
**Important update:** My current employer has given me permission to work for the previous employer, provided that certain criteria is met:
* I provide them with regular updates on the progression and estimated duration of the project.
* I manage my time such that this additional work does not negativley impact my current work for them i.e. do not work late into the night before a work day.
* I keep silence to anybody else of the works I currently do for my current employer. | 2018/10/17 | [
"https://workplace.stackexchange.com/questions/120952",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/92732/"
] | One important point which hasn't been raised: what your relationship will be with them, and how they will pay you.
There are two options: they consider you as a (part-time, fixed-length contract) employee, or they consider you as a contractor. **They cannot just "send you money".**
* In the first case, this may be a bit complex as you are no longer in the country, especially regarding taxes, social security contributions, etc. If you don't know in advance how long it will take, it can also be quite a headache for them in terms of contract, unless you agree on a fixed amount.
* In the second case, you would need to invoice them. But that means **being registered as a sole trader (or a company), declaring that revenue, and paying taxes and contributions** on that income. This is turn means:
+ quite a bit of overhead in terms of time it takes to do all that. How long it takes varies greatly from country to country. There are usually simplified regimes for low-revenue situations like this, but it's still a burden.
+ since you are the one paying all the taxes and contributions, you need to take that into account when deciding how much you will charge.
In some countries, there are companies that will do the interface for you: they will invoice the target company for you, and pay you (minus taxes, contributions, and their commission) as an employee. You should pick such a company in the country you are currently residing in to avoid the above-mentioned issues.
In all cases, check your contract with your current employer, and what the rules are in your current work country. You may need to notify or even get a formal OK from your current employer before you can work for someone else at the same time. | >
> Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time?
>
>
>
Yes, you could (not "should") - though beware of potential tax and conflict of interest implications. Whether or not you choose to do so is up to you.
>
> Or should I provide the assistance for free since it is my morale responsibility, even though I am not contractually obligated to?
>
>
>
No. You do not have a moral responsibility here. It is to all intents and purposes *impossible* to write non-trivial code that is perfect both now, and into the future for all time - if we all had to support, for free, code that we wrote years ago, for previous employers, then after a few years of such "obligations" piling up we'd not have time to do our current jobs (for which we're getting paid).
An interesting thought experiment would be: if that code you wrote a year ago proved instrumental in getting your former employer a big contract with a new customer, would they have a moral obligation to send you a big bonus for writing it, *even though you don't work there any more*? And would they actually do so? Few people would answer "yes" to either question. So why should the inverse expectation come with any such moral obligation?
You did the job to (presumably) the best of your ability at that time, and got paid a (presumably) fair wage in exchange. That was the business relationship you had with your employer back then. It's now over. If you choose to, you may decide to strike up another business relationship with that employer - but it would be very foolish for such a new relationship to involve working for free. |
120,952 | ### My previous employer wants me to fix a bug in the code I wrote while I was working for them. Should I provide assistance to them—on contract (paid) or for free—despite the fact I am no longer working for them?
**Background:**
Last summer I worked as an intern for a large manufacturing company. The duration of my contract was fixed to 3 months. I was paid an hourly rate for my work. My job responsibilities entailed IT support and software development. The software project that I worked on was a fairly simple server application. I worked on the project exclusively. Initially the project seemed to be a success, the software was working as intended. Before my contract concluded and I left the company, I made sure to leave extensive documentation on how to use the program and how to edit the source code should they need to.
I did not sign a contract specifically pertaining to this software project and any post deployment assistance it may require.
Since then I have started working for a different company as a full-time software developer in a different country.
**Problem:**
I have recently been contacted by my previous employer (this is over a year after my contract ended with them), saying that there is a small bug with the software that I previously wrote, and that they need my help to fix said problem. As previously mentioned I now work full-time in a different country. This means that going back there in person is out of the question. Though I do believe it will be possible to fix the bug remotely. If I were to help fix this bug it would require me to devote my free time (evenings/weekends) to assist them.
It is in my best interest to fix this bug so that I can still use the previous employer as a reference for future employment. I do not want them to be on bad terms with me.
**Question:**
Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time? Or should I provide the assistance for free since it is my moral responsibility, even though I am not contractually obligated to?
**Important update:** My current employer has given me permission to work for the previous employer, provided that certain criteria is met:
* I provide them with regular updates on the progression and estimated duration of the project.
* I manage my time such that this additional work does not negativley impact my current work for them i.e. do not work late into the night before a work day.
* I keep silence to anybody else of the works I currently do for my current employer. | 2018/10/17 | [
"https://workplace.stackexchange.com/questions/120952",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/92732/"
] | I had a former employer do this with me once. Here are your basic options:
1. Do it for free.
2. Tell them to go fish.
3. Send them your time estimate and hourly rate. Offer to fix it for a price.
This is a nice way to put it on them; you're not saying no, and willing to work with them, but you're not a chump.
I'd avoid (2), which pretty much burns the bridge, and recommend either (1) or (3).
If the reference/relationship is very important to you, then maybe do it for free this time, but if they ask for another favor, quote them a time and cost.
If you work for free, they lose respect for you.
I chose (3). They said no. | In addition to the excellent advice already provided by others, I would urge you to bear the following in mind:
1. Software, like anything else built by man, requires maintenance, and
hence, if they want to rely on it, they must plan and budget for
maintenance, regardless of who will be performing it.
2. The difference in cost between a proof of concept written by an intern and maintainable, production quality software written to perform roughly the same task can be anywhere between 1% and 99%, and is usually much closer to the latter.
Thinking about maintenance as ''just this one more little thing'' doesn't make the cost go away, it just keeps them from planning and budgeting for it.
You might need to make this clear to them before accepting any further work.
Don't phrase it like that, of course; that would be pedantic. But don't enter into any negotiations in which their position is based on ignoring or misunderstanding this. |
120,952 | ### My previous employer wants me to fix a bug in the code I wrote while I was working for them. Should I provide assistance to them—on contract (paid) or for free—despite the fact I am no longer working for them?
**Background:**
Last summer I worked as an intern for a large manufacturing company. The duration of my contract was fixed to 3 months. I was paid an hourly rate for my work. My job responsibilities entailed IT support and software development. The software project that I worked on was a fairly simple server application. I worked on the project exclusively. Initially the project seemed to be a success, the software was working as intended. Before my contract concluded and I left the company, I made sure to leave extensive documentation on how to use the program and how to edit the source code should they need to.
I did not sign a contract specifically pertaining to this software project and any post deployment assistance it may require.
Since then I have started working for a different company as a full-time software developer in a different country.
**Problem:**
I have recently been contacted by my previous employer (this is over a year after my contract ended with them), saying that there is a small bug with the software that I previously wrote, and that they need my help to fix said problem. As previously mentioned I now work full-time in a different country. This means that going back there in person is out of the question. Though I do believe it will be possible to fix the bug remotely. If I were to help fix this bug it would require me to devote my free time (evenings/weekends) to assist them.
It is in my best interest to fix this bug so that I can still use the previous employer as a reference for future employment. I do not want them to be on bad terms with me.
**Question:**
Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time? Or should I provide the assistance for free since it is my moral responsibility, even though I am not contractually obligated to?
**Important update:** My current employer has given me permission to work for the previous employer, provided that certain criteria is met:
* I provide them with regular updates on the progression and estimated duration of the project.
* I manage my time such that this additional work does not negativley impact my current work for them i.e. do not work late into the night before a work day.
* I keep silence to anybody else of the works I currently do for my current employer. | 2018/10/17 | [
"https://workplace.stackexchange.com/questions/120952",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/92732/"
] | >
> Should I negotiate a new contract with my previous employer and charge
> them money for this additional assistance that I would be providing
> them in my spare time? Or should I provide the assistance for free
> since it is my morale responsibility, even though I am not
> contractually obligated to?
>
>
>
There are no moral obligations in business.
You were paid by the hour, not by the result. And from what you described the company is seeking your assistance from a neutral position, they are not angry or threatening you.
Most likely, they already did a quick guestimate and believe that asking you to fix the bug will be faster, cheaper and possibly less likely to introduce other bugs than hiring someone new who is unfamiliar with the code.
Their request is an absolutely rational one. The person who wrote the code is usually the best person to fix a bug. Reaching out to you with a request for help is an obvious solution. Most likely, they will not be surprised by you asking for payment, and most likely they would not be losing sleep if you refused.
So **yes**, if you wish to, you can offer them to fix the bug at an hourly rate that you find justified. You should detail everything you mentioned above - that you are full-time employed, would complete this work in your spare time (important for an estimate of deadlines!) and that you can only do the work remotely.
And **yes**, you should ask for compensation for your time. Why would you do this for free? Why would you assume they expect you do it for free? Would they do something for free for you?
And that is all there is to it. I would abstain from the philosophical musings of some other answers. Why they found the bug now, whether or not they read your documentation, if they already tried fixing the bug with in-house people - all of that is of no consequence to your question.
Don't overthink simple things. | In addition to the excellent advice already provided by others, I would urge you to bear the following in mind:
1. Software, like anything else built by man, requires maintenance, and
hence, if they want to rely on it, they must plan and budget for
maintenance, regardless of who will be performing it.
2. The difference in cost between a proof of concept written by an intern and maintainable, production quality software written to perform roughly the same task can be anywhere between 1% and 99%, and is usually much closer to the latter.
Thinking about maintenance as ''just this one more little thing'' doesn't make the cost go away, it just keeps them from planning and budgeting for it.
You might need to make this clear to them before accepting any further work.
Don't phrase it like that, of course; that would be pedantic. But don't enter into any negotiations in which their position is based on ignoring or misunderstanding this. |
120,952 | ### My previous employer wants me to fix a bug in the code I wrote while I was working for them. Should I provide assistance to them—on contract (paid) or for free—despite the fact I am no longer working for them?
**Background:**
Last summer I worked as an intern for a large manufacturing company. The duration of my contract was fixed to 3 months. I was paid an hourly rate for my work. My job responsibilities entailed IT support and software development. The software project that I worked on was a fairly simple server application. I worked on the project exclusively. Initially the project seemed to be a success, the software was working as intended. Before my contract concluded and I left the company, I made sure to leave extensive documentation on how to use the program and how to edit the source code should they need to.
I did not sign a contract specifically pertaining to this software project and any post deployment assistance it may require.
Since then I have started working for a different company as a full-time software developer in a different country.
**Problem:**
I have recently been contacted by my previous employer (this is over a year after my contract ended with them), saying that there is a small bug with the software that I previously wrote, and that they need my help to fix said problem. As previously mentioned I now work full-time in a different country. This means that going back there in person is out of the question. Though I do believe it will be possible to fix the bug remotely. If I were to help fix this bug it would require me to devote my free time (evenings/weekends) to assist them.
It is in my best interest to fix this bug so that I can still use the previous employer as a reference for future employment. I do not want them to be on bad terms with me.
**Question:**
Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time? Or should I provide the assistance for free since it is my moral responsibility, even though I am not contractually obligated to?
**Important update:** My current employer has given me permission to work for the previous employer, provided that certain criteria is met:
* I provide them with regular updates on the progression and estimated duration of the project.
* I manage my time such that this additional work does not negativley impact my current work for them i.e. do not work late into the night before a work day.
* I keep silence to anybody else of the works I currently do for my current employer. | 2018/10/17 | [
"https://workplace.stackexchange.com/questions/120952",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/92732/"
] | >
> Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time?
>
>
>
Yes if you feel deeply with it. You are writing code so they can make a profit. As an aside, it's entirely possible your current company will not allow you to work. Check with your manager if you are allowed to do this before asking about the contract. Most companies I've seen have clauses/rules regarding working for a similar company while employed there.
>
> Or should I provide the assistance for free since it is my morale responsibility, even though I am not contractually obligated to?
>
>
>
No, I don't think you have a moral responsibility for fixing your error. If you wrote a software that solved world hunger, then yes, maybe in such a case. However, given that you were making money, and they were making money off you, then there is no moral obligation or what not. | >
> Should I negotiate a new contract with my previous employer and charge
> them money for this additional assistance that I would be providing
> them in my spare time? Or should I provide the assistance for free
> since it is my morale responsibility, even though I am not
> contractually obligated to?
>
>
>
There are no moral obligations in business.
You were paid by the hour, not by the result. And from what you described the company is seeking your assistance from a neutral position, they are not angry or threatening you.
Most likely, they already did a quick guestimate and believe that asking you to fix the bug will be faster, cheaper and possibly less likely to introduce other bugs than hiring someone new who is unfamiliar with the code.
Their request is an absolutely rational one. The person who wrote the code is usually the best person to fix a bug. Reaching out to you with a request for help is an obvious solution. Most likely, they will not be surprised by you asking for payment, and most likely they would not be losing sleep if you refused.
So **yes**, if you wish to, you can offer them to fix the bug at an hourly rate that you find justified. You should detail everything you mentioned above - that you are full-time employed, would complete this work in your spare time (important for an estimate of deadlines!) and that you can only do the work remotely.
And **yes**, you should ask for compensation for your time. Why would you do this for free? Why would you assume they expect you do it for free? Would they do something for free for you?
And that is all there is to it. I would abstain from the philosophical musings of some other answers. Why they found the bug now, whether or not they read your documentation, if they already tried fixing the bug with in-house people - all of that is of no consequence to your question.
Don't overthink simple things. |
120,952 | ### My previous employer wants me to fix a bug in the code I wrote while I was working for them. Should I provide assistance to them—on contract (paid) or for free—despite the fact I am no longer working for them?
**Background:**
Last summer I worked as an intern for a large manufacturing company. The duration of my contract was fixed to 3 months. I was paid an hourly rate for my work. My job responsibilities entailed IT support and software development. The software project that I worked on was a fairly simple server application. I worked on the project exclusively. Initially the project seemed to be a success, the software was working as intended. Before my contract concluded and I left the company, I made sure to leave extensive documentation on how to use the program and how to edit the source code should they need to.
I did not sign a contract specifically pertaining to this software project and any post deployment assistance it may require.
Since then I have started working for a different company as a full-time software developer in a different country.
**Problem:**
I have recently been contacted by my previous employer (this is over a year after my contract ended with them), saying that there is a small bug with the software that I previously wrote, and that they need my help to fix said problem. As previously mentioned I now work full-time in a different country. This means that going back there in person is out of the question. Though I do believe it will be possible to fix the bug remotely. If I were to help fix this bug it would require me to devote my free time (evenings/weekends) to assist them.
It is in my best interest to fix this bug so that I can still use the previous employer as a reference for future employment. I do not want them to be on bad terms with me.
**Question:**
Should I negotiate a new contract with my previous employer and charge them money for this additional assistance that I would be providing them in my spare time? Or should I provide the assistance for free since it is my moral responsibility, even though I am not contractually obligated to?
**Important update:** My current employer has given me permission to work for the previous employer, provided that certain criteria is met:
* I provide them with regular updates on the progression and estimated duration of the project.
* I manage my time such that this additional work does not negativley impact my current work for them i.e. do not work late into the night before a work day.
* I keep silence to anybody else of the works I currently do for my current employer. | 2018/10/17 | [
"https://workplace.stackexchange.com/questions/120952",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/92732/"
] | One important point which hasn't been raised: what your relationship will be with them, and how they will pay you.
There are two options: they consider you as a (part-time, fixed-length contract) employee, or they consider you as a contractor. **They cannot just "send you money".**
* In the first case, this may be a bit complex as you are no longer in the country, especially regarding taxes, social security contributions, etc. If you don't know in advance how long it will take, it can also be quite a headache for them in terms of contract, unless you agree on a fixed amount.
* In the second case, you would need to invoice them. But that means **being registered as a sole trader (or a company), declaring that revenue, and paying taxes and contributions** on that income. This is turn means:
+ quite a bit of overhead in terms of time it takes to do all that. How long it takes varies greatly from country to country. There are usually simplified regimes for low-revenue situations like this, but it's still a burden.
+ since you are the one paying all the taxes and contributions, you need to take that into account when deciding how much you will charge.
In some countries, there are companies that will do the interface for you: they will invoice the target company for you, and pay you (minus taxes, contributions, and their commission) as an employee. You should pick such a company in the country you are currently residing in to avoid the above-mentioned issues.
In all cases, check your contract with your current employer, and what the rules are in your current work country. You may need to notify or even get a formal OK from your current employer before you can work for someone else at the same time. | In addition to the excellent advice already provided by others, I would urge you to bear the following in mind:
1. Software, like anything else built by man, requires maintenance, and
hence, if they want to rely on it, they must plan and budget for
maintenance, regardless of who will be performing it.
2. The difference in cost between a proof of concept written by an intern and maintainable, production quality software written to perform roughly the same task can be anywhere between 1% and 99%, and is usually much closer to the latter.
Thinking about maintenance as ''just this one more little thing'' doesn't make the cost go away, it just keeps them from planning and budgeting for it.
You might need to make this clear to them before accepting any further work.
Don't phrase it like that, of course; that would be pedantic. But don't enter into any negotiations in which their position is based on ignoring or misunderstanding this. |
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