qid int64 1 74.7M | question stringlengths 12 33.8k | date stringlengths 10 10 | metadata list | response_j stringlengths 0 115k | response_k stringlengths 2 98.3k |
|---|---|---|---|---|---|
629,873 | I have a database with a report table. This table represents report data, and has constraints.
Now the application is used by firemen, and they might have to run off and put out some fires.
So in the middle of filling out data for this table, they might have to run off.
What we do is when the session run out we save the data to a draft table, where we simply serialize the object graph, no constraints (since we can't know if everything is in a valid state).
And when the fireman later wants to pull data back out we simply pull out the draft again.
This works fine!
However the firemen now wants to be able to search the table and the draft table.
So here I would like to maybe store all the data (including the draft) into one table, that I search, so I don't have to consolidate the search from two tables..
Is there some kind of database pattern for drafts?
What I want is a patternfor storing data without constraints (in draft mode) and with constraints (in final mode). | 2009/03/10 | [
"https://Stackoverflow.com/questions/629873",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/4189/"
] | I don't know if it this would qualify as a pattern, but I think that the cleanest way to go about this would be to create a view that does a union of the two tables and search against that. | I dont know of a Database pattern for Drafts, but I would suggest keeping your seperate table if you require validation and simply searching on both tables. |
629,873 | I have a database with a report table. This table represents report data, and has constraints.
Now the application is used by firemen, and they might have to run off and put out some fires.
So in the middle of filling out data for this table, they might have to run off.
What we do is when the session run out we save the data to a draft table, where we simply serialize the object graph, no constraints (since we can't know if everything is in a valid state).
And when the fireman later wants to pull data back out we simply pull out the draft again.
This works fine!
However the firemen now wants to be able to search the table and the draft table.
So here I would like to maybe store all the data (including the draft) into one table, that I search, so I don't have to consolidate the search from two tables..
Is there some kind of database pattern for drafts?
What I want is a patternfor storing data without constraints (in draft mode) and with constraints (in final mode). | 2009/03/10 | [
"https://Stackoverflow.com/questions/629873",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/4189/"
] | Go with the simple solution: create a View which is just a union of the two tables (which should be fairly straight forward as they I assume they both have (almost) identical structures) and then run searches on that as the source if they want to include both.
I wouldn't actually merge the complete and draft data at any point: the potential for error and accidental use of unvalidated data seems huge.
You wouldn't be working on an interface for the IRS in the UK at the moment, would you? If not, sounds like DK have gone for a similar (in principle) solution to this problem (I used to work for a UK Fire and Rescue Service). | I dont know of a Database pattern for Drafts, but I would suggest keeping your seperate table if you require validation and simply searching on both tables. |
629,873 | I have a database with a report table. This table represents report data, and has constraints.
Now the application is used by firemen, and they might have to run off and put out some fires.
So in the middle of filling out data for this table, they might have to run off.
What we do is when the session run out we save the data to a draft table, where we simply serialize the object graph, no constraints (since we can't know if everything is in a valid state).
And when the fireman later wants to pull data back out we simply pull out the draft again.
This works fine!
However the firemen now wants to be able to search the table and the draft table.
So here I would like to maybe store all the data (including the draft) into one table, that I search, so I don't have to consolidate the search from two tables..
Is there some kind of database pattern for drafts?
What I want is a patternfor storing data without constraints (in draft mode) and with constraints (in final mode). | 2009/03/10 | [
"https://Stackoverflow.com/questions/629873",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/4189/"
] | I don't know if it this would qualify as a pattern, but I think that the cleanest way to go about this would be to create a view that does a union of the two tables and search against that. | I've thought pretty long and hard about this problem, and here is my answer:
1. store drafts and their corresponding validated entities in the same table. have a is\_draft column
2. use is\_draft=1 to turn off validation in triggers and check constraints, or your ORM validation rules
3. many of your fields will have to be nullable or have defaults
this has several advantages:
1. drafts and their corresponding validated entities are stored in the same table
2. drafts and their corresponding validated entities *have the same id* . why is this important?
imagine you start a quote for a customer. save it. it gets an id. you are looking at it in a web browser /quotes/id/55 . you start editing that quote, remove a required value because it was wrong. you have to go next door to look it up, but you want to save it. the id number should not change.
it would also be confusing for people if they are collaborating on the same document and its id keeps changing if it moves in and out of a valid state. |
629,873 | I have a database with a report table. This table represents report data, and has constraints.
Now the application is used by firemen, and they might have to run off and put out some fires.
So in the middle of filling out data for this table, they might have to run off.
What we do is when the session run out we save the data to a draft table, where we simply serialize the object graph, no constraints (since we can't know if everything is in a valid state).
And when the fireman later wants to pull data back out we simply pull out the draft again.
This works fine!
However the firemen now wants to be able to search the table and the draft table.
So here I would like to maybe store all the data (including the draft) into one table, that I search, so I don't have to consolidate the search from two tables..
Is there some kind of database pattern for drafts?
What I want is a patternfor storing data without constraints (in draft mode) and with constraints (in final mode). | 2009/03/10 | [
"https://Stackoverflow.com/questions/629873",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/4189/"
] | Go with the simple solution: create a View which is just a union of the two tables (which should be fairly straight forward as they I assume they both have (almost) identical structures) and then run searches on that as the source if they want to include both.
I wouldn't actually merge the complete and draft data at any point: the potential for error and accidental use of unvalidated data seems huge.
You wouldn't be working on an interface for the IRS in the UK at the moment, would you? If not, sounds like DK have gone for a similar (in principle) solution to this problem (I used to work for a UK Fire and Rescue Service). | I've thought pretty long and hard about this problem, and here is my answer:
1. store drafts and their corresponding validated entities in the same table. have a is\_draft column
2. use is\_draft=1 to turn off validation in triggers and check constraints, or your ORM validation rules
3. many of your fields will have to be nullable or have defaults
this has several advantages:
1. drafts and their corresponding validated entities are stored in the same table
2. drafts and their corresponding validated entities *have the same id* . why is this important?
imagine you start a quote for a customer. save it. it gets an id. you are looking at it in a web browser /quotes/id/55 . you start editing that quote, remove a required value because it was wrong. you have to go next door to look it up, but you want to save it. the id number should not change.
it would also be confusing for people if they are collaborating on the same document and its id keeps changing if it moves in and out of a valid state. |
24,074,194 | We are using WSO2 DSS and implementing an Employee search API. The service provides something like Google search where when you start typing matched results are returned.
For this we have to use LIKE clause in the SQL statement. If we try to define the query in the below way
**Method 1**
SELECT Columns
FROM EMPTable
WHERE FirstName LIKE ':pName%'
and try to pass only the string from the service URL it will not recognize the parameter. It will pass ":pName" to query to DB.
If we define it below way
**Method 2**
SELECT Columns FROM EMPTable WHERE FirstName LIKE :pName
and pass 'SomeText%' from the query string this works fine. The second method is a poor implementation as the percentage marks and quotation marks tends to get encoded and mess up the service calls.
**Method 3**
SELECT Columns FROM EMPTable WHERE FirstName LIKE '?%'
This method work as I want. The issue is let's say I want something like
*SELECT Columns FROM EMPTable WHERE FirstName LIKE '?%' OR LastName LIKE '?%'*
then I would have to define two input parameters and ask the service user to pass in the same input to two different parameters.
Is there any way we can implement Method 1? Or for Method 3 where we can give the same parameter two ordinals? | 2014/06/06 | [
"https://Stackoverflow.com/questions/24074194",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/1519793/"
] | You can use the Concat function within the SQL statement so for example CONCAT(:pName,'%') | I usually use REPLACE function, for instance: REPLACE(:pname,'\*','%'). So in URI we can use \* as usual in search engines.
I think REPLACE function is in every SQL dialect |
106,602 | Forgive my ignorance but I am truly uncertain.
Here is my situation:
I have dual booted a Linux distro and Windows 7 on my machine. Windows 7 sole purpose is for gaming, that's all. I'm not planning to get Windows Update nor game patches neither. Network adapters are disabled too. Should I let Windows Firewall ON?
I'll be happy if I can save some processing power when the firewall is off or I'm just over thinking? | 2015/11/27 | [
"https://security.stackexchange.com/questions/106602",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/78676/"
] | Firewalls generally operate at the network layer, if you have no network (you state the network adapters are disabled) there is nothing for the firewall to do, therefore, from a security perspective, turning off the firewall isn't going to be an issue.
Obviously this only holds true while the network adapters are disabled. | **You are just overthinking.**
Firewall is not needed if you computer is not connected to the internet. If you are playing multiplayer games, and you need to connect to the internet, you might encounter some problems if you enable the firewall. However, Leaving the firewall off for the sake of gaming might be a bad idea. |
1,013 | As I approach my mid-50's, I'm looking forward to a few more decades of cycling if all goes well. How can one avoid and/or mitigate age related issues in order to maintain cycling fitness?
I've thought a lot about this and already engage in several practices. I'm sure that I can always learn more. | 2010/09/15 | [
"https://bicycles.stackexchange.com/questions/1013",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/-1/"
] | Just to get started with a couple of things I already do.
1. Strength training with some emphasis on lower body. Since cycling is not a weight bearing exercise, older cyclists are at a greater risk for pelvic, hip and leg fractures.
2. An advanced dynamic flexibility routine in order to maintain mobility, coordination and balance.
***Update***
As noted by darkcanuck's comment below, cycling as a cause of bone loss may very well be incorrect. In the article, Dr. Mirkin advocates vitamin D supplementation to prevent bone loss, and I've also read other sources recommending the same thing. So, probably a good idea especially for those in Northern climes.
As for strength training, I have other reasons for how it's been beneficial for cycling as I get older.
* One is that a few years ago I was experiencing considerable neck/shoulder pain on long rides. At the time I was spending long hours at the computer and cycling was my dominant physical activity. I came to the conclusion that my neck/shoulder issues were posture related and so developed a strength and flexibility program to correct my posture. In doing that I have been able to eliminate the pain and now ride comfortably on long rides.
* Another issue that developed a year or so ago was knee pain. After seeing my doc and a physical therapist, I was prescribed a new 'hip' focused addition to my strength routine. Apparently I had some muscular imbalances related to cycling. Since starting this new routine 6 months ago, the knee issues are significantly improved.
For further info on strength training for older, and even younger cyclists, here's an [article from Velonews](http://velonews.competitor.com/2010/09/training-center/velonews-training-center-is-strength-training-for-cycling-a-good-idea_139198). | I'm not sure what kind of cycling you do. But, a mountain biker mentioned to me that more suspension is appreciated more as you get older.
Some seat post suspension might help. The reviews for this are great, but it's a bit pricey:
<http://www.bikeradar.com/gear/category/components/seat-post-seat-pin/product/thudbuster-lt-10308> |
1,013 | As I approach my mid-50's, I'm looking forward to a few more decades of cycling if all goes well. How can one avoid and/or mitigate age related issues in order to maintain cycling fitness?
I've thought a lot about this and already engage in several practices. I'm sure that I can always learn more. | 2010/09/15 | [
"https://bicycles.stackexchange.com/questions/1013",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/-1/"
] | Just to get started with a couple of things I already do.
1. Strength training with some emphasis on lower body. Since cycling is not a weight bearing exercise, older cyclists are at a greater risk for pelvic, hip and leg fractures.
2. An advanced dynamic flexibility routine in order to maintain mobility, coordination and balance.
***Update***
As noted by darkcanuck's comment below, cycling as a cause of bone loss may very well be incorrect. In the article, Dr. Mirkin advocates vitamin D supplementation to prevent bone loss, and I've also read other sources recommending the same thing. So, probably a good idea especially for those in Northern climes.
As for strength training, I have other reasons for how it's been beneficial for cycling as I get older.
* One is that a few years ago I was experiencing considerable neck/shoulder pain on long rides. At the time I was spending long hours at the computer and cycling was my dominant physical activity. I came to the conclusion that my neck/shoulder issues were posture related and so developed a strength and flexibility program to correct my posture. In doing that I have been able to eliminate the pain and now ride comfortably on long rides.
* Another issue that developed a year or so ago was knee pain. After seeing my doc and a physical therapist, I was prescribed a new 'hip' focused addition to my strength routine. Apparently I had some muscular imbalances related to cycling. Since starting this new routine 6 months ago, the knee issues are significantly improved.
For further info on strength training for older, and even younger cyclists, here's an [article from Velonews](http://velonews.competitor.com/2010/09/training-center/velonews-training-center-is-strength-training-for-cycling-a-good-idea_139198). | This is an old question of mine from the early days of bicycles.stackexchange, and I never really felt that there was an optimal answer. So, here's another shot at it.
A couple of recent tweets by [Joe Friel](http://joefriel.typepad.com/blog/)... (FYI - Joe Friel is an endurance sports coach best known as an elite triathlon and cycling coach as well as the author of several books on endurance sports.)
* "As you age the more important workout intensity and strength training become. Unfortunately, most aging athletes do the opposite."
* "What we call “aging” is really a sign of disuse & misuse. Most people age much too quickly. Exercise & nutrition are the keys."
I did a bit of searching on Friel's site and found **[an excellent article](http://www.joefrielsblog.com/2011/11/q-a-.html)** that pretty explicitly answers my original question. To paraphrase and summarize, here are the key factors that the aging cyclist (athlete) needs to be mindful of:
* Workout Intensity - As one ages, there is a tendency to increase workout duration and reduce intensity. It is beneficial to workout at relatively high intensity levels with the emphasis on muscular endurance, anaerobic endurance and sprint power. Higher intensity reduces workout time and helps maintain muscle mass.
* Strength Training - There is considerable research indicating that strength training is highly beneficial to the maintenance of bone density and muscle mass.
* Sleep - As one ages, the recovery time from exertion increases. Good sleep and rest are vital to allow the body to recover from physical stress and exertion.
* Nutrition - Quality nutrition is key, featuring micronutrient rich fruits, vegetables, and animal protein. Additionally, consuming sugars during a long, intense workout; and starch for recovery following the workout.
And to finish off, here's a quote from *Middle Age: A Natural History* by David Bainbridge,
>
> The average man's body fat rises from 23 per cent to 29 per cent over the fifth and sixth decades of his life, while women's will reach 38 per cent.
>
>
>
So, keep on riding. |
1,013 | As I approach my mid-50's, I'm looking forward to a few more decades of cycling if all goes well. How can one avoid and/or mitigate age related issues in order to maintain cycling fitness?
I've thought a lot about this and already engage in several practices. I'm sure that I can always learn more. | 2010/09/15 | [
"https://bicycles.stackexchange.com/questions/1013",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/-1/"
] | Just to get started with a couple of things I already do.
1. Strength training with some emphasis on lower body. Since cycling is not a weight bearing exercise, older cyclists are at a greater risk for pelvic, hip and leg fractures.
2. An advanced dynamic flexibility routine in order to maintain mobility, coordination and balance.
***Update***
As noted by darkcanuck's comment below, cycling as a cause of bone loss may very well be incorrect. In the article, Dr. Mirkin advocates vitamin D supplementation to prevent bone loss, and I've also read other sources recommending the same thing. So, probably a good idea especially for those in Northern climes.
As for strength training, I have other reasons for how it's been beneficial for cycling as I get older.
* One is that a few years ago I was experiencing considerable neck/shoulder pain on long rides. At the time I was spending long hours at the computer and cycling was my dominant physical activity. I came to the conclusion that my neck/shoulder issues were posture related and so developed a strength and flexibility program to correct my posture. In doing that I have been able to eliminate the pain and now ride comfortably on long rides.
* Another issue that developed a year or so ago was knee pain. After seeing my doc and a physical therapist, I was prescribed a new 'hip' focused addition to my strength routine. Apparently I had some muscular imbalances related to cycling. Since starting this new routine 6 months ago, the knee issues are significantly improved.
For further info on strength training for older, and even younger cyclists, here's an [article from Velonews](http://velonews.competitor.com/2010/09/training-center/velonews-training-center-is-strength-training-for-cycling-a-good-idea_139198). | I can add one thing: It is possible to exercise a muscle beyond it's metabolic capacity and cause serious muscle injury as a result. This happens with non-trivial frequency in sports "boot camp" environments where the participants will be run ragged all day with insufficient food, then subjected to, eg, intense squatting exercises.
Surprisingly, muscles do not expend energy when they contract, but rather the energy is expended when the muscles "reset". If the muscles contract and then it turns out that there is not enough available glucose, et al, to reset them, the muscle cells "depolarize" and die.
In the "boot camp" scenario this results in intense muscle pain in the major muscles of the legs, followed by "rhabdomyolysis" -- the breakdown of muscle -- and "myoblobinuria" -- the excretion of the breakdown products in the urine (seen as a rust-colored sediment -- myoglobin -- in the urine).
In young, healty people there is generally enough "reserve" muscle that, though this injury is effectively permanent, it does not result in any noticeable disability. (However, the myoglobinuria can result in serious kidney damage, and there is a secondary condition where the damaged muscles of the leg swell up and constrict that can also be quite serious.)
In older people, however, especially those on statin drugs and some diabetes meds, the resulting injury itself can be significant and life changing, especially if repeated several times.
The injury is most apt to occur in situations such as a relatively long, intense climb near the end of several hours of cycling, but can occur in shorter episodes of intense energy expenditure. The symptom will be a "muscle pull" type pain that doesn't appear until about 36 hours after the exercise (in fact, long enough removed that the individual may not associate the pain with the prior activity). And, where a regular "muscle pull" usually clears up in 3-6 weeks, the rhabdo injury remains painful for 3-6 months. |
1,013 | As I approach my mid-50's, I'm looking forward to a few more decades of cycling if all goes well. How can one avoid and/or mitigate age related issues in order to maintain cycling fitness?
I've thought a lot about this and already engage in several practices. I'm sure that I can always learn more. | 2010/09/15 | [
"https://bicycles.stackexchange.com/questions/1013",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/-1/"
] | This is an old question of mine from the early days of bicycles.stackexchange, and I never really felt that there was an optimal answer. So, here's another shot at it.
A couple of recent tweets by [Joe Friel](http://joefriel.typepad.com/blog/)... (FYI - Joe Friel is an endurance sports coach best known as an elite triathlon and cycling coach as well as the author of several books on endurance sports.)
* "As you age the more important workout intensity and strength training become. Unfortunately, most aging athletes do the opposite."
* "What we call “aging” is really a sign of disuse & misuse. Most people age much too quickly. Exercise & nutrition are the keys."
I did a bit of searching on Friel's site and found **[an excellent article](http://www.joefrielsblog.com/2011/11/q-a-.html)** that pretty explicitly answers my original question. To paraphrase and summarize, here are the key factors that the aging cyclist (athlete) needs to be mindful of:
* Workout Intensity - As one ages, there is a tendency to increase workout duration and reduce intensity. It is beneficial to workout at relatively high intensity levels with the emphasis on muscular endurance, anaerobic endurance and sprint power. Higher intensity reduces workout time and helps maintain muscle mass.
* Strength Training - There is considerable research indicating that strength training is highly beneficial to the maintenance of bone density and muscle mass.
* Sleep - As one ages, the recovery time from exertion increases. Good sleep and rest are vital to allow the body to recover from physical stress and exertion.
* Nutrition - Quality nutrition is key, featuring micronutrient rich fruits, vegetables, and animal protein. Additionally, consuming sugars during a long, intense workout; and starch for recovery following the workout.
And to finish off, here's a quote from *Middle Age: A Natural History* by David Bainbridge,
>
> The average man's body fat rises from 23 per cent to 29 per cent over the fifth and sixth decades of his life, while women's will reach 38 per cent.
>
>
>
So, keep on riding. | I'm not sure what kind of cycling you do. But, a mountain biker mentioned to me that more suspension is appreciated more as you get older.
Some seat post suspension might help. The reviews for this are great, but it's a bit pricey:
<http://www.bikeradar.com/gear/category/components/seat-post-seat-pin/product/thudbuster-lt-10308> |
1,013 | As I approach my mid-50's, I'm looking forward to a few more decades of cycling if all goes well. How can one avoid and/or mitigate age related issues in order to maintain cycling fitness?
I've thought a lot about this and already engage in several practices. I'm sure that I can always learn more. | 2010/09/15 | [
"https://bicycles.stackexchange.com/questions/1013",
"https://bicycles.stackexchange.com",
"https://bicycles.stackexchange.com/users/-1/"
] | I can add one thing: It is possible to exercise a muscle beyond it's metabolic capacity and cause serious muscle injury as a result. This happens with non-trivial frequency in sports "boot camp" environments where the participants will be run ragged all day with insufficient food, then subjected to, eg, intense squatting exercises.
Surprisingly, muscles do not expend energy when they contract, but rather the energy is expended when the muscles "reset". If the muscles contract and then it turns out that there is not enough available glucose, et al, to reset them, the muscle cells "depolarize" and die.
In the "boot camp" scenario this results in intense muscle pain in the major muscles of the legs, followed by "rhabdomyolysis" -- the breakdown of muscle -- and "myoblobinuria" -- the excretion of the breakdown products in the urine (seen as a rust-colored sediment -- myoglobin -- in the urine).
In young, healty people there is generally enough "reserve" muscle that, though this injury is effectively permanent, it does not result in any noticeable disability. (However, the myoglobinuria can result in serious kidney damage, and there is a secondary condition where the damaged muscles of the leg swell up and constrict that can also be quite serious.)
In older people, however, especially those on statin drugs and some diabetes meds, the resulting injury itself can be significant and life changing, especially if repeated several times.
The injury is most apt to occur in situations such as a relatively long, intense climb near the end of several hours of cycling, but can occur in shorter episodes of intense energy expenditure. The symptom will be a "muscle pull" type pain that doesn't appear until about 36 hours after the exercise (in fact, long enough removed that the individual may not associate the pain with the prior activity). And, where a regular "muscle pull" usually clears up in 3-6 weeks, the rhabdo injury remains painful for 3-6 months. | I'm not sure what kind of cycling you do. But, a mountain biker mentioned to me that more suspension is appreciated more as you get older.
Some seat post suspension might help. The reviews for this are great, but it's a bit pricey:
<http://www.bikeradar.com/gear/category/components/seat-post-seat-pin/product/thudbuster-lt-10308> |
92,463 | I have a wireless network at my house. My wife's computer connects just fine to it and the internet (I am using her computer wirelessly to ask this question).
My computer will wirelessly connect to the network, but I cannot access the internet via my wireless connection. (I tried to ping google and that fails too.)
If I connect to my wired network at my house the internet works just fine.
I can also connect to other wireless networks (and through them the internet) at other places (at the in-laws and on the commuting on the train).
I know I am able to connect to the network because I am able to access my router over my wireless network. I get an IP address. Every thing seems fine. But when I try to access the internet both Firefox and IE give me the unable to connect page.
Any Ideas on what I can check to fix this? | 2010/01/07 | [
"https://superuser.com/questions/92463",
"https://superuser.com",
"https://superuser.com/users/2183/"
] | You may have had a Microsoft update that made come changes to your driver - see if you can roll back your computer to a time when it worked, also check in system restore and see what changes have been made to your computer.
If you have the wireless card driver, then I'd uninstall and reinstall it. By the way, which router do you have, which wireless card and driver version? | Wich encryption type do you use? Maybe the router is set to WPA or WPA2 but your PC does only support WEP. |
92,463 | I have a wireless network at my house. My wife's computer connects just fine to it and the internet (I am using her computer wirelessly to ask this question).
My computer will wirelessly connect to the network, but I cannot access the internet via my wireless connection. (I tried to ping google and that fails too.)
If I connect to my wired network at my house the internet works just fine.
I can also connect to other wireless networks (and through them the internet) at other places (at the in-laws and on the commuting on the train).
I know I am able to connect to the network because I am able to access my router over my wireless network. I get an IP address. Every thing seems fine. But when I try to access the internet both Firefox and IE give me the unable to connect page.
Any Ideas on what I can check to fix this? | 2010/01/07 | [
"https://superuser.com/questions/92463",
"https://superuser.com",
"https://superuser.com/users/2183/"
] | Connect wired. Open a command prompt and run IPCONFIG /ALL or the Linux equivalent. Then connect wireless. Run again. Compare the wired/wireless DNS server entries. Compare the gateway entries. They should be the same. | You may have had a Microsoft update that made come changes to your driver - see if you can roll back your computer to a time when it worked, also check in system restore and see what changes have been made to your computer.
If you have the wireless card driver, then I'd uninstall and reinstall it. By the way, which router do you have, which wireless card and driver version? |
92,463 | I have a wireless network at my house. My wife's computer connects just fine to it and the internet (I am using her computer wirelessly to ask this question).
My computer will wirelessly connect to the network, but I cannot access the internet via my wireless connection. (I tried to ping google and that fails too.)
If I connect to my wired network at my house the internet works just fine.
I can also connect to other wireless networks (and through them the internet) at other places (at the in-laws and on the commuting on the train).
I know I am able to connect to the network because I am able to access my router over my wireless network. I get an IP address. Every thing seems fine. But when I try to access the internet both Firefox and IE give me the unable to connect page.
Any Ideas on what I can check to fix this? | 2010/01/07 | [
"https://superuser.com/questions/92463",
"https://superuser.com",
"https://superuser.com/users/2183/"
] | Connect wired. Open a command prompt and run IPCONFIG /ALL or the Linux equivalent. Then connect wireless. Run again. Compare the wired/wireless DNS server entries. Compare the gateway entries. They should be the same. | Does your wired connection work?
If no, you may need to re-install drivers or reset the websocket
-If yes, then Are you running linux?
--If yes, then it is very likely that the problem is your wireless driver (i.e. my laptop only works while setting it on top of the wireless router.) There may or may not be a solution to this problem.
--If no, try to make sure your creditials for the wireless network are correct.
If all else fails reset the wireless router and set a new password/wireless name.
Make sure your internet setting on your computer match your wife's computer's settings. |
92,463 | I have a wireless network at my house. My wife's computer connects just fine to it and the internet (I am using her computer wirelessly to ask this question).
My computer will wirelessly connect to the network, but I cannot access the internet via my wireless connection. (I tried to ping google and that fails too.)
If I connect to my wired network at my house the internet works just fine.
I can also connect to other wireless networks (and through them the internet) at other places (at the in-laws and on the commuting on the train).
I know I am able to connect to the network because I am able to access my router over my wireless network. I get an IP address. Every thing seems fine. But when I try to access the internet both Firefox and IE give me the unable to connect page.
Any Ideas on what I can check to fix this? | 2010/01/07 | [
"https://superuser.com/questions/92463",
"https://superuser.com",
"https://superuser.com/users/2183/"
] | Had this ever worked?
If you can log into your router are you able to verify that you are not running any sort of MAC filtering? You could also try and go into the network settings of your NIC and spoof your MAC address to that of you wifes laptop.
I would also remove the saved wireless internet connections you may have accumulated that refer to your home router.
If this has never worked, can you check that your router and your Wifi are running matching specs? You could possibly have a B adapter and your router could be set to allow G only or something along those lines. | Wich encryption type do you use? Maybe the router is set to WPA or WPA2 but your PC does only support WEP. |
92,463 | I have a wireless network at my house. My wife's computer connects just fine to it and the internet (I am using her computer wirelessly to ask this question).
My computer will wirelessly connect to the network, but I cannot access the internet via my wireless connection. (I tried to ping google and that fails too.)
If I connect to my wired network at my house the internet works just fine.
I can also connect to other wireless networks (and through them the internet) at other places (at the in-laws and on the commuting on the train).
I know I am able to connect to the network because I am able to access my router over my wireless network. I get an IP address. Every thing seems fine. But when I try to access the internet both Firefox and IE give me the unable to connect page.
Any Ideas on what I can check to fix this? | 2010/01/07 | [
"https://superuser.com/questions/92463",
"https://superuser.com",
"https://superuser.com/users/2183/"
] | Connect wired. Open a command prompt and run IPCONFIG /ALL or the Linux equivalent. Then connect wireless. Run again. Compare the wired/wireless DNS server entries. Compare the gateway entries. They should be the same. | Wich encryption type do you use? Maybe the router is set to WPA or WPA2 but your PC does only support WEP. |
69,044,205 | Good day, I need to debug the application on a device in another city. How can I do that? Are there any Android debugging apps?
Thanks in advance for your reply. | 2021/09/03 | [
"https://Stackoverflow.com/questions/69044205",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/9943542/"
] | [Genymotionis](https://www.genymotion.com/) is great, since BlueStack App Player now forces you to install some apps to continue using free version. I tried Genymotion and quite happy with speed for App development, haven't tried gaming yet. | this tool might come in handy, it is an android app that can expose the ADB over network:
[Remote ADB Shell](https://forum.xda-developers.com/t/app-2-2-remote-adb-shell.2373265/) |
69,044,205 | Good day, I need to debug the application on a device in another city. How can I do that? Are there any Android debugging apps?
Thanks in advance for your reply. | 2021/09/03 | [
"https://Stackoverflow.com/questions/69044205",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/9943542/"
] | You can set Location Lat and Long in either code or emulator if using android studio. for remote debugging several apps are there on Google Play, for that you have to once connected with usb and then run some command in cmd depends on app(adb tcpip {Port No.}). you will need adb file for remote debugging though. | this tool might come in handy, it is an android app that can expose the ADB over network:
[Remote ADB Shell](https://forum.xda-developers.com/t/app-2-2-remote-adb-shell.2373265/) |
154,905 | I'm in a team that is comprised of 4 backenders, 2 designers and 1 frontend (me), and my teamleader.
Most of the work i do is maintenance, mostly related to bugs from code that was written by other people and everytime a major project needs frontend, i'm assigned with all of the work, and i start to pile up tasks.
It happens that, when i have to work on new projects, they just sort of hit my desk, and i have to manage to do all of it alone. Whenever i have a question, i really don't know who to ask, because my teammates don't even bother to help me, or complain when i ask for their help, saying that "it's frontend". My teamleader is (of all of my teammates) the one that is most involved with the frontend, and he keeps forgetting about me, even skipping my 1-1s, and has most of his time occupied by meetings.
This is driving me crazy, because it seems that my work is not valued (my teamleader keeps forgetting about me on 1-1s, and i just can't seem to talk to him), and nobody really cares about what i'm doing (. I don't want to come across as a whiner on the workplace, but i't seems that i have no choice, because if i don't ask for their attention, i keep hitting obstacles that i don't understand and end up getting frustrated because i'm just afraid to ask them for help.
How can i not feel frustrated/neglected/forgotten about this? | 2020/03/12 | [
"https://workplace.stackexchange.com/questions/154905",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/113335/"
] | Ensure your immediate superior / manager (not the teamleader) knows about your workload when you are assigned all these projects to do alone. If you are missing deadlines, explain that you are receiving no support from team members and are largely being left to manage alone.
Have you tried turning to the employee(s) who were responsible for your on-boarding? Are they the same employees who refuse to help you now?
Also, have you considered emailing your teammates for help instead of asking them directly? Bear in mind that programmers "in the zone" hate interruptions; email may be a safer channel for requesting help. | Radical transparency! Make it known what you're working on and who you're waiting for.
About overwork: maintain a list of tasks you have on your plate in priority order. Four hours before your scheduled 1:1 meetings with your team leader, email them the list. Ask for them to review it and tell you if you need to change priorities.
Then, when somebody asks for something, respond with your list of priorities and say it's been reviewed by the team leader.
As far as being ignored, it's unfortunately common for people who work solo in their discipline, like you. You should ask for information / help / advice in writing, and you should put "blocked waiting for Jane's input" or other such things on your priority list. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | Sounds like the April 1st calendar crash. Delete whole day events on April 1st (and unsubscribe from calendars that give you public holidays on that day), and that should fix crashes that occur when you go to month view in March. | Drag the appointment to an empty date. Then you should be able to delete it. Worked for me. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | This is how applications crash on iOS - so you may want to check your settings to see if your iPad is sending crash reports to Apple.
Settings App -> General -> Diagnostics & Usage
You can also look in the Data submenu from the above screen and scroll down to look for **LatestCrash.plist** and see if the date matches when your iCal quit.
In general, it's not possible (even as a developer) to read these reports without access to the iCal source code and you have some short term things you can do to isolate the issue further.
First is to remove any notifications (turn of WiFi and cellular data) and reboot the iPad. If iCal crashes, then it's due to the calendar data on the device and not some external cause. You can then remove your calendar information, account by account to clear up which account has the data corruption that is causing iCal to have a problem. Worst case, you will have to connect your iPad to a computer (iTunes) and force a sync to erase the calendar data on the iPad and replace it with data from the computer to clear the data that is causing the crash.
Apple will likely fix the crash (even with bad data - the program should handle it and let you know an event is broken or ignored and why) in the upcoming updates - but you can report the crash to add weight to this particular bug getting fixed.
You can also take an overkill (but faster) approach to erase all content and settings on the iPad and set it up again.
It's unlikely the data will come back corrupt from your calendar sources (or the backup) but if it does, at least you'll know a bit more about how to isolate which calendar is causing iCal to have problems. | Sounds like the April 1st calendar crash. Delete whole day events on April 1st (and unsubscribe from calendars that give you public holidays on that day), and that should fix crashes that occur when you go to month view in March. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | Sounds like the April 1st calendar crash. Delete whole day events on April 1st (and unsubscribe from calendars that give you public holidays on that day), and that should fix crashes that occur when you go to month view in March. | I deleted the subscription to DE Holidays events (German holidays) - and it fixed the problem, even though I have other all-day events listed on April 1. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | Sounds like the April 1st calendar crash. Delete whole day events on April 1st (and unsubscribe from calendars that give you public holidays on that day), and that should fix crashes that occur when you go to month view in March. | If your calendar appears as a blank page and then closes you are unable to delete or change all day events from the 25 hours imposed by daylight saving to fewer hours.
In that case change your location a territory that does not use daylight saving, e.g. Most of Africa. When you reopen Calender you should be able to edit your all day events |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | Apple support tell me that the problem is known, their engineers are working on it and the temporary solution is to deselect the uk holiday calendar, and by implication any other calendar where events on April 1st are all day, and to change any all day events on April 1st on your own calendars to say 0100 to 2300.
It occurs that people might have several day events stretching over 31st March and 1st April which might also need amending.
Conspiracy paranoids might think the original programmer thought, ahah it's April Fools Day in 2013, but I guess it's more likely to be an unintended consequence of the 31st not having enough hours for a 24 hr all day event. | I deleted the subscription to DE Holidays events (German holidays) - and it fixed the problem, even though I have other all-day events listed on April 1. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | This is how applications crash on iOS - so you may want to check your settings to see if your iPad is sending crash reports to Apple.
Settings App -> General -> Diagnostics & Usage
You can also look in the Data submenu from the above screen and scroll down to look for **LatestCrash.plist** and see if the date matches when your iCal quit.
In general, it's not possible (even as a developer) to read these reports without access to the iCal source code and you have some short term things you can do to isolate the issue further.
First is to remove any notifications (turn of WiFi and cellular data) and reboot the iPad. If iCal crashes, then it's due to the calendar data on the device and not some external cause. You can then remove your calendar information, account by account to clear up which account has the data corruption that is causing iCal to have a problem. Worst case, you will have to connect your iPad to a computer (iTunes) and force a sync to erase the calendar data on the iPad and replace it with data from the computer to clear the data that is causing the crash.
Apple will likely fix the crash (even with bad data - the program should handle it and let you know an event is broken or ignored and why) in the upcoming updates - but you can report the crash to add weight to this particular bug getting fixed.
You can also take an overkill (but faster) approach to erase all content and settings on the iPad and set it up again.
It's unlikely the data will come back corrupt from your calendar sources (or the backup) but if it does, at least you'll know a bit more about how to isolate which calendar is causing iCal to have problems. | Apple support tell me that the problem is known, their engineers are working on it and the temporary solution is to deselect the uk holiday calendar, and by implication any other calendar where events on April 1st are all day, and to change any all day events on April 1st on your own calendars to say 0100 to 2300.
It occurs that people might have several day events stretching over 31st March and 1st April which might also need amending.
Conspiracy paranoids might think the original programmer thought, ahah it's April Fools Day in 2013, but I guess it's more likely to be an unintended consequence of the 31st not having enough hours for a 24 hr all day event. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | If your calendar appears as a blank page and then closes you are unable to delete or change all day events from the 25 hours imposed by daylight saving to fewer hours.
In that case change your location a territory that does not use daylight saving, e.g. Most of Africa. When you reopen Calender you should be able to edit your all day events | I deleted the subscription to DE Holidays events (German holidays) - and it fixed the problem, even though I have other all-day events listed on April 1. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | If your calendar appears as a blank page and then closes you are unable to delete or change all day events from the 25 hours imposed by daylight saving to fewer hours.
In that case change your location a territory that does not use daylight saving, e.g. Most of Africa. When you reopen Calender you should be able to edit your all day events | Drag the appointment to an empty date. Then you should be able to delete it. Worked for me. |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | This is how applications crash on iOS - so you may want to check your settings to see if your iPad is sending crash reports to Apple.
Settings App -> General -> Diagnostics & Usage
You can also look in the Data submenu from the above screen and scroll down to look for **LatestCrash.plist** and see if the date matches when your iCal quit.
In general, it's not possible (even as a developer) to read these reports without access to the iCal source code and you have some short term things you can do to isolate the issue further.
First is to remove any notifications (turn of WiFi and cellular data) and reboot the iPad. If iCal crashes, then it's due to the calendar data on the device and not some external cause. You can then remove your calendar information, account by account to clear up which account has the data corruption that is causing iCal to have a problem. Worst case, you will have to connect your iPad to a computer (iTunes) and force a sync to erase the calendar data on the iPad and replace it with data from the computer to clear the data that is causing the crash.
Apple will likely fix the crash (even with bad data - the program should handle it and let you know an event is broken or ignored and why) in the upcoming updates - but you can report the crash to add weight to this particular bug getting fixed.
You can also take an overkill (but faster) approach to erase all content and settings on the iPad and set it up again.
It's unlikely the data will come back corrupt from your calendar sources (or the backup) but if it does, at least you'll know a bit more about how to isolate which calendar is causing iCal to have problems. | If your calendar appears as a blank page and then closes you are unable to delete or change all day events from the 25 hours imposed by daylight saving to fewer hours.
In that case change your location a territory that does not use daylight saving, e.g. Most of Africa. When you reopen Calender you should be able to edit your all day events |
62,508 | I have been using my calendar fine but this afternoon when I click on the tile it briefly opens (1 sec) and then closes itself. I have waited 30 mins, I have turned iPad off & back on and still no joy. | 2012/08/30 | [
"https://apple.stackexchange.com/questions/62508",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/28303/"
] | Sounds like the April 1st calendar crash. Delete whole day events on April 1st (and unsubscribe from calendars that give you public holidays on that day), and that should fix crashes that occur when you go to month view in March. | Apple support tell me that the problem is known, their engineers are working on it and the temporary solution is to deselect the uk holiday calendar, and by implication any other calendar where events on April 1st are all day, and to change any all day events on April 1st on your own calendars to say 0100 to 2300.
It occurs that people might have several day events stretching over 31st March and 1st April which might also need amending.
Conspiracy paranoids might think the original programmer thought, ahah it's April Fools Day in 2013, but I guess it's more likely to be an unintended consequence of the 31st not having enough hours for a 24 hr all day event. |
134 | It doesn't matter whether they are for free or for purchase as long as they are compatible. | 2010/08/17 | [
"https://apple.stackexchange.com/questions/134",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/18/"
] | The best commercial packages of themes for the iWork apps, in my experience, are those from [Jumsoft.](http://www.jumsoft.com/)(under Design) They produce themes for both Pages and Keynote, as well as animation and art packs.
For free templates, [iWorkCommunity](http://www.iworkcommunity.com) has a ton of Pages templates, and some decent Numbers templates as well for basic use. [KeynoteUser](http://www.keynoteuser.com/resources/) also produces commercial themes, in addition to having some freebies, and an excellent blog and collection of links for other sources of high quality stuff. | Interesting. You can find some nice examples on Themeforest, they should have a big list of such items.
<http://wisset.com/premium-keynote-templates/> |
134 | It doesn't matter whether they are for free or for purchase as long as they are compatible. | 2010/08/17 | [
"https://apple.stackexchange.com/questions/134",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/18/"
] | The best commercial packages of themes for the iWork apps, in my experience, are those from [Jumsoft.](http://www.jumsoft.com/)(under Design) They produce themes for both Pages and Keynote, as well as animation and art packs.
For free templates, [iWorkCommunity](http://www.iworkcommunity.com) has a ton of Pages templates, and some decent Numbers templates as well for basic use. [KeynoteUser](http://www.keynoteuser.com/resources/) also produces commercial themes, in addition to having some freebies, and an excellent blog and collection of links for other sources of high quality stuff. | Klariti has SDLC and business templates over but these are for professionals.
<http://klariti.com/apple-iwork-templates/> |
134 | It doesn't matter whether they are for free or for purchase as long as they are compatible. | 2010/08/17 | [
"https://apple.stackexchange.com/questions/134",
"https://apple.stackexchange.com",
"https://apple.stackexchange.com/users/18/"
] | Interesting. You can find some nice examples on Themeforest, they should have a big list of such items.
<http://wisset.com/premium-keynote-templates/> | Klariti has SDLC and business templates over but these are for professionals.
<http://klariti.com/apple-iwork-templates/> |
23,571,339 | I do know the difference between concurrency (CPU process swapping) and parallelism (processes running in real-time parallel on multiple cores). What I wish to know is what role threads and processes play in all of this. I am aware that every OS is different, and that CPU scheduling varies from OS to OS and VM to VM. In general, threads have much less overhead, and CPU swapping is generally quicker for threads, compared to processes. But when I read about multi-process computing, everyone seems to agree that this is the only alternative for computing on multiple CPUs in parallel.
Does this mean that threads are not capable of running in real parallel on multiple CPU cores -- or does it mean that multi-process computing is the only viable option if you need to run calculations on multiple physical CPU chips, such as cluster network supercomputers?
I would appreciate a clarification! | 2014/05/09 | [
"https://Stackoverflow.com/questions/23571339",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/1790803/"
] | First, to clarify the terminology that you are using:
* a process is an entity managed by an operating system, typically the execution of a program;
* a thread is an entity within a process that executes instructions sequentially.
In this context, processes have an amount of state that is maintained by the operating system to record details of registers, memory, permissions etc. The size of this state is typically larger than that of a thread and therefore the overhead of managing processes (as you say) is greater. See [Wikipedia](http://en.wikipedia.org/wiki/Process_%28computing%29) for more details.
So, to answer your question, threads and processes (as defined above) **can** be executed in parallel on multiple processors, if the operating system or underlying architecture by which they are executed **supports it**.
Conventional parallel processors are shared-memory and a conventional operating system is Linux. Linux supports the parallel execution of both processes and threads on shared memory (symmetric) multicores, but it does not support the execution of processes (or threads) over multiple processors (that is, unless they are in a shared-memory configuration). There have been a number of distributed operating systems that are designed to support the execution of processes or threads over multiple processors without shared memory, but these never caught on; see [Wikipedia](http://en.wikipedia.org/wiki/Distributed_operating_system).
Conventional cluster-based systems (such as supercomputers) employ parallel execution between processors using MPI. MPI is a communication interface between processes that execute in operating system instances on different processors; it doesn't support other process operations such as scheduling. (At the risk of complicating things further, because MPI processes are executed by operating systems, a single processor can run multiple MPI processes and/or a single MPI process can also execute multiple threads!)
Finally, a simple (although unconventional) example, where threads and processes have a slightly different meaning, is the XMOS processor architecture. This allows multiple processor chips to be connected together and for multiple threads of sequential execution to execute over and communicate between them, **without** an operating system. | >
> everyone seems to agree that this is the only alternative for computing on multiple CPUs in parallel.
>
>
>
I have never heard this. In any case it is not true.
>
> Does this mean that threads are not capable of running in real parallel on multiple CPU cores
>
>
>
The thread is the unit of scheduling in most OS'es. Processes are not scheduling units. At the very most they come into play as inputs to scheduling heuristics. Threads run on CPUs (in parallel), not processes.
>
> or does it mean that multi-process computing is the only viable option if you need to run calculations on multiple physical CPU chips, such as cluster network supercomputers?
>
>
>
No. Processes do not enhance the scheduling capabilities of the OS.
The question was not very precisely asked. I hope I could clarify the important points. |
246,238 | I'm new to web development and I've started working on a project in my company that uses DJANGO. I feel it flexible to start my development straight first from the templates. I think it will be easier if I visualize things first. So my question: Is it okay to start with a template rather than starting with models first? Will I stumble on to any sort of confusions if I go by this method of development? | 2014/06/27 | [
"https://softwareengineering.stackexchange.com/questions/246238",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/138900/"
] | Starting with the user experience and how that works is actually a good way to start off.
It ensures that what you build is fit for purpose and that you end up building what needs to be built and not things you **think** you will need.
See [User Centered Design](http://en.wikipedia.org/wiki/User-centered_design) on Wikipedia. | There is no right answer. You will probably be going back and forth between models and templates before you settle on something which works.
You should start of with use-cases or usage scenarios which include the view templates. As you write those, you will expose some system concepts, many of which will become your core models. Once you see what is possible with your models, you may realize that you have more use-cases which can take advantage of the models. Or you may discover that your models have complex relationships which will lead you to refactoring the models. And that could lead you to more use-cases. And so on...Eventually, you'll run out of use-cases, and your model will be just right, assuming that you have normalized them.
When you do your use-cases, you have to expose a minimal subset of models to your users. Make sure that you understand which models are exposed and which ones are not exposed. |
389,844 | So I am going to be developing atleast 5-6 Res end points . ( all distinct and stateless )
Now I am debating on the following:
* Should they be combined as single war / ear or deploy each service separately ?
* deploying them as single war - down time during deployment should that be a concern ? ( with load balancer - ideally there shouldnt be any down time correct ? )
* in case of any issues in case of a single war all services would be impacted Vs a single service - how realistic is this ?
* any other parameters that should be considered ? | 2019/04/05 | [
"https://softwareengineering.stackexchange.com/questions/389844",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104831/"
] | The entire point of microservices is that they are independently deployable and scaleable. If you're talking about 5-6 literal endpoints (uri endpoints, sockets, message types - effectively 5-6 callable functions) then putting them together is fine. Having a single function per deployment is probably pathologically/impractically micro.
If you're talking about 5-6 entities (and all of the operations to work on them), it becomes a matter of tradeoffs. Are the entities likely to change together? Is your CI/CD process mature? Will your project go under if you don't ship tomorrow?
If you're talking about 5-6 concepts, each with multiple entities and all of the operations they need... then they should probably get deployed separately. I mean, you can certainly deploy them all together for ease of implementation - but they're not really microservices at that point. | Many of the answers that Microservices architectures raise regarding this topic are tightly related to the company's business strategy towards the market.
Microservices is not an end. It's a mean to an end. It's the business strategy who on way or another drives the solution to implement. You have to ask first the stakeholders which behaviour is acceptable.
>
> Should they be combined as single war/ear or deploy each service
> separately?
>
>
>
As @Telastyn answered, it depends on what those 5-6 endpoints are. Their responsibilities, their criticality.
>
> deploying them as single war - downtime during deployment should that
> be a concern?
>
>
>
With or without balancing, it should be. If endpoints cover different business capabilities, you should ask the stakeholders what downtime is acceptable for each capability. You might find that some services (endpoints) are more critic than others. Some could remain down for longer than others without causing significant losses for the company. Imagine what would happen if Amazon took down its *Cart service* or the *payment gateways* for a couple minutes.
>
> in case of any issues in case of a single war all services would be
> impacted Vs a single service - how realistic is this?
>
>
>
Of course, a DDoS attack would compromise all the system (if the system is comprised of those 5-6 endpoints). What lives as a whole, dies as a whole too.
>
> any other parameters that should be considered?
>
>
>
Too many to be summarised in a short and concise answer.
The unwritten rule of Microservices is **divide and conquer**. How much to divide is purely strategy. |
2,894,118 | I am taking a course in game theory. For proving the Nash equilibrium we require Brouwer's fixed point theorem. But I have not taken a topology course so I am finding the proof difficult to understand. You may explain the same Brouwer's in little easy way. | 2018/08/25 | [
"https://math.stackexchange.com/questions/2894118",
"https://math.stackexchange.com",
"https://math.stackexchange.com/users/-1/"
] | You could have a look at [John Milnor's take](http://web.cs.elte.hu/~karatson/hairy-ball.pdf). His methods are all quite elementary (the most difficult prerequisite needed here is the well-known-but-rarely-proved [change of variables theorem](https://en.wikipedia.org/wiki/Integration_by_substitution#Substitution_for_multiple_variables)). However, in my opinion this proof is indeed quite mysterious and John himself seems to agree with that. | ***Topological Spaces** From Distance To Nighborhood* by Gerard Buskes and Arnoud van Rooij provide a nice 'intuitive proof' (Section~4.21). It is not exact, but it has plenty of diagrams and explanations. |
2,894,118 | I am taking a course in game theory. For proving the Nash equilibrium we require Brouwer's fixed point theorem. But I have not taken a topology course so I am finding the proof difficult to understand. You may explain the same Brouwer's in little easy way. | 2018/08/25 | [
"https://math.stackexchange.com/questions/2894118",
"https://math.stackexchange.com",
"https://math.stackexchange.com/users/-1/"
] | Of course "easy" has a large degree of subjectivity to it. But there is a famous proof due to Emanuel Sperner that was (and still is) striking for minimizing the amount of topology needed.
[These](http://math.mit.edu/~fox/MAT307-lecture03.pdf) course notes of Jacob Fox give an exposition using Sperner's Lemma. The document starts from scratch and proves Brouwer's Theorem (for all $n$) in just under 2.5 pages. | ***Topological Spaces** From Distance To Nighborhood* by Gerard Buskes and Arnoud van Rooij provide a nice 'intuitive proof' (Section~4.21). It is not exact, but it has plenty of diagrams and explanations. |
2,894,118 | I am taking a course in game theory. For proving the Nash equilibrium we require Brouwer's fixed point theorem. But I have not taken a topology course so I am finding the proof difficult to understand. You may explain the same Brouwer's in little easy way. | 2018/08/25 | [
"https://math.stackexchange.com/questions/2894118",
"https://math.stackexchange.com",
"https://math.stackexchange.com/users/-1/"
] | Of course "easy" has a large degree of subjectivity to it. But there is a famous proof due to Emanuel Sperner that was (and still is) striking for minimizing the amount of topology needed.
[These](http://math.mit.edu/~fox/MAT307-lecture03.pdf) course notes of Jacob Fox give an exposition using Sperner's Lemma. The document starts from scratch and proves Brouwer's Theorem (for all $n$) in just under 2.5 pages. | You could have a look at [John Milnor's take](http://web.cs.elte.hu/~karatson/hairy-ball.pdf). His methods are all quite elementary (the most difficult prerequisite needed here is the well-known-but-rarely-proved [change of variables theorem](https://en.wikipedia.org/wiki/Integration_by_substitution#Substitution_for_multiple_variables)). However, in my opinion this proof is indeed quite mysterious and John himself seems to agree with that. |
30,739 | The Sankt Goar line crosses the german town of Sankt Goar and separates the dialects that have *t* in words like *wat* and *dat* and the dialects that have *s* in the corresponding words *was* and *das*. Is this change abrupt? Does the consonant literally change from one side of the line to the other,does it happen gradually through slightly different pronunciations or do the dialects that are spoken near the line use both forms,slowly fading into just one of them the further away they are from the isogloss? | 2019/03/02 | [
"https://linguistics.stackexchange.com/questions/30739",
"https://linguistics.stackexchange.com",
"https://linguistics.stackexchange.com/users/22572/"
] | Good question!
Isoglosses are generally drawn as these nice, hard-edged lines on a map. On one side of the Sankt Goar line, you have *das*, and on the other side, you have *dat*.
The problem is, nothing in linguistics is ever this clear-cut. Even the boundaries between languages are fuzzy: [you can walk from Rome to Lisbon without ever crossing a hard line between two languages](https://linguistics.stackexchange.com/a/29921/10559).
So isoglosses are a sort of "good enough" approximation. *In general*, someone on this side is more likely to use *das*, and someone on that side is more likely to use *dat*. But if you went to Sankt Goar itself, you wouldn't find half the people using *das* and half of them using *dat*: more likely, the people near the line use both versions, maybe interchangeably, maybe in a sort of diglossia (using *das* in some registers and *dat* in others). And as you get further away from the line, the probability that you'll hear one instead of the other increases. | Yes, this particular change is aprupt. There are no intermediate forms between *wat* and *was* (like \*wats) nor *dat* and *das*. There may be places where you can find speakers who you either form, maybe separated by age. After all, at least in Saarland *Rheinfänkisch* (the dialect with *was* and *das*) is spreading into formerly *Moselfränkisch* (the dialect with *wat* and *dat*) territory. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | If you want strong authentication without the cost of sending SMS you can use TOTP with the [Google authenticator app](https://github.com/google/google-authenticator).
Indeed, the pin solution doesn't seem to add a lot of additional security. I also don't fully understand the mechanism. They enter 3 digits from a 6 digit pin. How did they obtain the 6 digit pin and how are the tree digits selected? Also 10^3 is not such a large number, meaning the pin can be brute forced if no measures are taken. If you can clarify the pin mechanism I might be able to give more insights on it's security benefits.
EDIT: based on your update this is already a weak form of two factor authentication since the pin is communicated via e-mail. Why there are 3 digits selected out of the 6 in the e-mail is still a mystery to me. The reason I say 'weak' is because 3 digit pin code is very short and can be brute forced if no other protection is present.
Also, the dropdown thing to prevent keyloggers from logging the pin is a really weak form of protection. If you have the capability of logging keystrokes you also have the capability to check which number is selected. Or does anyone believe there are cases where keylogging is possible but monitoring clicks is not? Maybe in a hardware keylogger? | The "part that you know" second factor could be *which* 3 of the 6 emailed characters to use (Mary uses 1st, 2nd, 5th, John: 1-2-6, Fred and Janet: 4-5-6)... not certain how you'd teach your folks which ones, but once taught that secret shouldn't have to be transmitted again. And then use tight lockdowns too.
SMS is potentially vulnerable to stingray but take that with a grain of salt--sized for how motivated people are to break into your system. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | I find it hard to see what security benefits this could provide. In multifactor authentication, the point is to use different factors — i.e., "something you know", "something you have", "something you are". Just repeating the same factor twice seems a bit pointless.
But let me speculate some about what the purpose could be.
**1. Stop keyloggers**
Only dumb malware tries to get passwords by blindly logging key strokes. Requiring the use of a drop down menu may protect against some malware, but in the end trying to hide user input when the computer is already infected is a loosing game. See [this question](https://security.stackexchange.com/questions/127889/whats-the-safest-way-to-enter-information-on-a-website/) for a related discussion. In the end, I think the benefits are small here.
**2. Increase entropy**
If you add a six digit PIN to the password, you get 106 times as many combinations to brute force or almost 20 extra bits of entropy, right? (Or 103 times or 10 bits if you only count the three digits entered.) Yeah, but why not just require a longer password?
Perhaps you want to split it in two to make one part (the PIN) truly random and thereby give protection to users who pick weak passwords. But what does this protect against? For online attacks, you should already have rate limiting in place to deal with this. For offline attacks, you would need to hash the PIN together with the password to get any benefits. But since you can log in providing only three out of six digits they don't seem to be doing this (unless they keep 20 hashes for all possible digit combinations).
**3. Limit the effect of stolen passwords**
Let's say your password gets stolen (say in a phishing attack). If the attack is only performed once, the attacker will only get half of the PIN. She will therefore not be able to easily log in if she is asked for other digits than the ones she got.
I don't see this as a big benefit. Just repeat the attack a couple of times, or attempt to login multiple times (or from different IP's) until you are prompted for the digits you have.
**Drawbacks**
* It makes users more likely to write the PIN (and perhaps the password while they are at it) down on a post it or an email.
* You can not log in using only a password manager. Why make it harder for people who use safe methods to manage their passwords?
**Conclusion**
I can't see any security benefits that would motivate having the user memorise an extra PIN and go through the hassle of picking numbers from drop down menus. To me this smells of [security theater](https://en.wikipedia.org/wiki/Security_theater). But perhaps I am missing something.
*Edit: Yes, I did miss something. See [supercat's answer](https://security.stackexchange.com/a/128670/98538). It's a very good point, but I'm not sure I would think it is worth it anyway.* | If you want strong authentication without the cost of sending SMS you can use TOTP with the [Google authenticator app](https://github.com/google/google-authenticator).
Indeed, the pin solution doesn't seem to add a lot of additional security. I also don't fully understand the mechanism. They enter 3 digits from a 6 digit pin. How did they obtain the 6 digit pin and how are the tree digits selected? Also 10^3 is not such a large number, meaning the pin can be brute forced if no measures are taken. If you can clarify the pin mechanism I might be able to give more insights on it's security benefits.
EDIT: based on your update this is already a weak form of two factor authentication since the pin is communicated via e-mail. Why there are 3 digits selected out of the 6 in the e-mail is still a mystery to me. The reason I say 'weak' is because 3 digit pin code is very short and can be brute forced if no other protection is present.
Also, the dropdown thing to prevent keyloggers from logging the pin is a really weak form of protection. If you have the capability of logging keystrokes you also have the capability to check which number is selected. Or does anyone believe there are cases where keylogging is possible but monitoring clicks is not? Maybe in a hardware keylogger? |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | The point of [multi-factor authentication](https://en.wikipedia.org/wiki/Multi-factor_authentication) is to require information from multiple sources so that if a user is compromised in one way (say they write their password down somewhere and it's found), then there is still a layer of security preventing account access.
Usually, the three types of authentication information are something you
* **know** - like a password or a pin number you've memorized
* **have** - a phone or some other access token you keep on you
* **are** - a fingerprint or other biometric
Both a password and pin are considered in the first category, so **the pin likely doesn't add much extra security** considering there's a risk that they could both be compromised at the same time (sure, there's no/less risk of keylogging. But what if the information is intercepted over the network or some other form of capture?).
As for advantages, it's hard to say without more information. In this case, it sounds like having a pin is cheaper than doing a "proper" two-factor authentication system. Maybe the threat model is keyloggers on user computers, and this *might* be an appropriate fix. | What's going on here is that your competitor is trying to use a poor man's substitute in place of a robust second-factor for authentication. For whatever business reasons they don't want to deal with putting in place the infrastructure on their end to implement a one-time code/OTP mechanism (the most common 2FA setup) to provide that robust second authentication factor. (Or turn to a third-party to handle implementing OTPs for them under an authentication-as-a-service model.) The results of this are rather predictable: for reasons others have pointed out this poor man's substitute isn't nearly as difficult for an attacker to overcome as a 2FA mechanism where you must get a one-use code from a separate device ("something you have") each time you sign in.
nevertheless, there are some things about this arrangement that make it somewhat preferable to just using a password for authentication alone. By far, the two greatest problems with relying only on a password to authenticate a user are (a) the fact that a great many users liberally reuse passwords across many accounts and (b) the tendency of a great many users to choose easier-to-remember but very weak passwords. Requiring entry of a PIN that has been randomly generated by the service provides a pretty significant additional layer of protection against these huge threats. (Although *distributing that PIN via email* is a lousy practice, for a number of reasons.)
Of course, none of that will help you a great deal if an attacker can get malware on to your PC/device that will record your PIN as you enter it. Or if he or she can trick you into entering it into a phishing site. Here, the drop-down arrangement of entering three random digits from the six-digit PIN might provide some modest benefit in some scenarios. Many modern keyloggers will take screenshots of the mouse cursor every time the user clicks something, but some simpler/more rudimentary malware still sticks to capturing only keystrokes. Regarding theft of the PIN via phishing...well, here there's even less utility provided, simply because needing to input three randomly selected digits out of a PIN comprised of *only six digits* usually isn't going that imposing a problem. (Again, for reasons others have already well explained.) Still, one could argue that in some scenarios that arrangement may provide some bit (if a small bit) of additional utility vs. simply having the user enter their full PIN each time. (Maybe.)
All of the above being said, using a real two-factor authentication setup would certainly be preferable from a security standpoint. Especially if you're using one-use codes/OTPs generated by a hardware token (most secure) or smartphone authenticator app. No real contest. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | A system which locks out an account, even temporarily, in response to invalid password attempts will make it very easy to conduct a denial-of-service attack against someone. Using a two-part authentication makes it possible to have very strict lockout policies on the second part while still remaining resistant to denial-of-service attacks. If someone found out that a person's password on one system was Justin-Bieber, a system with a single part password wouldn't be able to distinguish targeted break-in attempts using variations on that password (e.g. Justin-Bieber1, Justin4Bieber, etc.) from random password entries which are intended to trigger a denial-of-service.
Splitting the password into two parts would mean that an attacker would get notice that the first part was correct *but* the most likely prize would not be access to the account, but merely the ability to trigger a lockdown on it until the real user authenticates via other means; since the user would know that someone else had the primary password, the user would then change that password, rendering it useless. | What's going on here is that your competitor is trying to use a poor man's substitute in place of a robust second-factor for authentication. For whatever business reasons they don't want to deal with putting in place the infrastructure on their end to implement a one-time code/OTP mechanism (the most common 2FA setup) to provide that robust second authentication factor. (Or turn to a third-party to handle implementing OTPs for them under an authentication-as-a-service model.) The results of this are rather predictable: for reasons others have pointed out this poor man's substitute isn't nearly as difficult for an attacker to overcome as a 2FA mechanism where you must get a one-use code from a separate device ("something you have") each time you sign in.
nevertheless, there are some things about this arrangement that make it somewhat preferable to just using a password for authentication alone. By far, the two greatest problems with relying only on a password to authenticate a user are (a) the fact that a great many users liberally reuse passwords across many accounts and (b) the tendency of a great many users to choose easier-to-remember but very weak passwords. Requiring entry of a PIN that has been randomly generated by the service provides a pretty significant additional layer of protection against these huge threats. (Although *distributing that PIN via email* is a lousy practice, for a number of reasons.)
Of course, none of that will help you a great deal if an attacker can get malware on to your PC/device that will record your PIN as you enter it. Or if he or she can trick you into entering it into a phishing site. Here, the drop-down arrangement of entering three random digits from the six-digit PIN might provide some modest benefit in some scenarios. Many modern keyloggers will take screenshots of the mouse cursor every time the user clicks something, but some simpler/more rudimentary malware still sticks to capturing only keystrokes. Regarding theft of the PIN via phishing...well, here there's even less utility provided, simply because needing to input three randomly selected digits out of a PIN comprised of *only six digits* usually isn't going that imposing a problem. (Again, for reasons others have already well explained.) Still, one could argue that in some scenarios that arrangement may provide some bit (if a small bit) of additional utility vs. simply having the user enter their full PIN each time. (Maybe.)
All of the above being said, using a real two-factor authentication setup would certainly be preferable from a security standpoint. Especially if you're using one-use codes/OTPs generated by a hardware token (most secure) or smartphone authenticator app. No real contest. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | I find it hard to see what security benefits this could provide. In multifactor authentication, the point is to use different factors — i.e., "something you know", "something you have", "something you are". Just repeating the same factor twice seems a bit pointless.
But let me speculate some about what the purpose could be.
**1. Stop keyloggers**
Only dumb malware tries to get passwords by blindly logging key strokes. Requiring the use of a drop down menu may protect against some malware, but in the end trying to hide user input when the computer is already infected is a loosing game. See [this question](https://security.stackexchange.com/questions/127889/whats-the-safest-way-to-enter-information-on-a-website/) for a related discussion. In the end, I think the benefits are small here.
**2. Increase entropy**
If you add a six digit PIN to the password, you get 106 times as many combinations to brute force or almost 20 extra bits of entropy, right? (Or 103 times or 10 bits if you only count the three digits entered.) Yeah, but why not just require a longer password?
Perhaps you want to split it in two to make one part (the PIN) truly random and thereby give protection to users who pick weak passwords. But what does this protect against? For online attacks, you should already have rate limiting in place to deal with this. For offline attacks, you would need to hash the PIN together with the password to get any benefits. But since you can log in providing only three out of six digits they don't seem to be doing this (unless they keep 20 hashes for all possible digit combinations).
**3. Limit the effect of stolen passwords**
Let's say your password gets stolen (say in a phishing attack). If the attack is only performed once, the attacker will only get half of the PIN. She will therefore not be able to easily log in if she is asked for other digits than the ones she got.
I don't see this as a big benefit. Just repeat the attack a couple of times, or attempt to login multiple times (or from different IP's) until you are prompted for the digits you have.
**Drawbacks**
* It makes users more likely to write the PIN (and perhaps the password while they are at it) down on a post it or an email.
* You can not log in using only a password manager. Why make it harder for people who use safe methods to manage their passwords?
**Conclusion**
I can't see any security benefits that would motivate having the user memorise an extra PIN and go through the hassle of picking numbers from drop down menus. To me this smells of [security theater](https://en.wikipedia.org/wiki/Security_theater). But perhaps I am missing something.
*Edit: Yes, I did miss something. See [supercat's answer](https://security.stackexchange.com/a/128670/98538). It's a very good point, but I'm not sure I would think it is worth it anyway.* | The "part that you know" second factor could be *which* 3 of the 6 emailed characters to use (Mary uses 1st, 2nd, 5th, John: 1-2-6, Fred and Janet: 4-5-6)... not certain how you'd teach your folks which ones, but once taught that secret shouldn't have to be transmitted again. And then use tight lockdowns too.
SMS is potentially vulnerable to stingray but take that with a grain of salt--sized for how motivated people are to break into your system. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | If you want strong authentication without the cost of sending SMS you can use TOTP with the [Google authenticator app](https://github.com/google/google-authenticator).
Indeed, the pin solution doesn't seem to add a lot of additional security. I also don't fully understand the mechanism. They enter 3 digits from a 6 digit pin. How did they obtain the 6 digit pin and how are the tree digits selected? Also 10^3 is not such a large number, meaning the pin can be brute forced if no measures are taken. If you can clarify the pin mechanism I might be able to give more insights on it's security benefits.
EDIT: based on your update this is already a weak form of two factor authentication since the pin is communicated via e-mail. Why there are 3 digits selected out of the 6 in the e-mail is still a mystery to me. The reason I say 'weak' is because 3 digit pin code is very short and can be brute forced if no other protection is present.
Also, the dropdown thing to prevent keyloggers from logging the pin is a really weak form of protection. If you have the capability of logging keystrokes you also have the capability to check which number is selected. Or does anyone believe there are cases where keylogging is possible but monitoring clicks is not? Maybe in a hardware keylogger? | The point of [multi-factor authentication](https://en.wikipedia.org/wiki/Multi-factor_authentication) is to require information from multiple sources so that if a user is compromised in one way (say they write their password down somewhere and it's found), then there is still a layer of security preventing account access.
Usually, the three types of authentication information are something you
* **know** - like a password or a pin number you've memorized
* **have** - a phone or some other access token you keep on you
* **are** - a fingerprint or other biometric
Both a password and pin are considered in the first category, so **the pin likely doesn't add much extra security** considering there's a risk that they could both be compromised at the same time (sure, there's no/less risk of keylogging. But what if the information is intercepted over the network or some other form of capture?).
As for advantages, it's hard to say without more information. In this case, it sounds like having a pin is cheaper than doing a "proper" two-factor authentication system. Maybe the threat model is keyloggers on user computers, and this *might* be an appropriate fix. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | A system which locks out an account, even temporarily, in response to invalid password attempts will make it very easy to conduct a denial-of-service attack against someone. Using a two-part authentication makes it possible to have very strict lockout policies on the second part while still remaining resistant to denial-of-service attacks. If someone found out that a person's password on one system was Justin-Bieber, a system with a single part password wouldn't be able to distinguish targeted break-in attempts using variations on that password (e.g. Justin-Bieber1, Justin4Bieber, etc.) from random password entries which are intended to trigger a denial-of-service.
Splitting the password into two parts would mean that an attacker would get notice that the first part was correct *but* the most likely prize would not be access to the account, but merely the ability to trigger a lockdown on it until the real user authenticates via other means; since the user would know that someone else had the primary password, the user would then change that password, rendering it useless. | The "part that you know" second factor could be *which* 3 of the 6 emailed characters to use (Mary uses 1st, 2nd, 5th, John: 1-2-6, Fred and Janet: 4-5-6)... not certain how you'd teach your folks which ones, but once taught that secret shouldn't have to be transmitted again. And then use tight lockdowns too.
SMS is potentially vulnerable to stingray but take that with a grain of salt--sized for how motivated people are to break into your system. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | I find it hard to see what security benefits this could provide. In multifactor authentication, the point is to use different factors — i.e., "something you know", "something you have", "something you are". Just repeating the same factor twice seems a bit pointless.
But let me speculate some about what the purpose could be.
**1. Stop keyloggers**
Only dumb malware tries to get passwords by blindly logging key strokes. Requiring the use of a drop down menu may protect against some malware, but in the end trying to hide user input when the computer is already infected is a loosing game. See [this question](https://security.stackexchange.com/questions/127889/whats-the-safest-way-to-enter-information-on-a-website/) for a related discussion. In the end, I think the benefits are small here.
**2. Increase entropy**
If you add a six digit PIN to the password, you get 106 times as many combinations to brute force or almost 20 extra bits of entropy, right? (Or 103 times or 10 bits if you only count the three digits entered.) Yeah, but why not just require a longer password?
Perhaps you want to split it in two to make one part (the PIN) truly random and thereby give protection to users who pick weak passwords. But what does this protect against? For online attacks, you should already have rate limiting in place to deal with this. For offline attacks, you would need to hash the PIN together with the password to get any benefits. But since you can log in providing only three out of six digits they don't seem to be doing this (unless they keep 20 hashes for all possible digit combinations).
**3. Limit the effect of stolen passwords**
Let's say your password gets stolen (say in a phishing attack). If the attack is only performed once, the attacker will only get half of the PIN. She will therefore not be able to easily log in if she is asked for other digits than the ones she got.
I don't see this as a big benefit. Just repeat the attack a couple of times, or attempt to login multiple times (or from different IP's) until you are prompted for the digits you have.
**Drawbacks**
* It makes users more likely to write the PIN (and perhaps the password while they are at it) down on a post it or an email.
* You can not log in using only a password manager. Why make it harder for people who use safe methods to manage their passwords?
**Conclusion**
I can't see any security benefits that would motivate having the user memorise an extra PIN and go through the hassle of picking numbers from drop down menus. To me this smells of [security theater](https://en.wikipedia.org/wiki/Security_theater). But perhaps I am missing something.
*Edit: Yes, I did miss something. See [supercat's answer](https://security.stackexchange.com/a/128670/98538). It's a very good point, but I'm not sure I would think it is worth it anyway.* | What's going on here is that your competitor is trying to use a poor man's substitute in place of a robust second-factor for authentication. For whatever business reasons they don't want to deal with putting in place the infrastructure on their end to implement a one-time code/OTP mechanism (the most common 2FA setup) to provide that robust second authentication factor. (Or turn to a third-party to handle implementing OTPs for them under an authentication-as-a-service model.) The results of this are rather predictable: for reasons others have pointed out this poor man's substitute isn't nearly as difficult for an attacker to overcome as a 2FA mechanism where you must get a one-use code from a separate device ("something you have") each time you sign in.
nevertheless, there are some things about this arrangement that make it somewhat preferable to just using a password for authentication alone. By far, the two greatest problems with relying only on a password to authenticate a user are (a) the fact that a great many users liberally reuse passwords across many accounts and (b) the tendency of a great many users to choose easier-to-remember but very weak passwords. Requiring entry of a PIN that has been randomly generated by the service provides a pretty significant additional layer of protection against these huge threats. (Although *distributing that PIN via email* is a lousy practice, for a number of reasons.)
Of course, none of that will help you a great deal if an attacker can get malware on to your PC/device that will record your PIN as you enter it. Or if he or she can trick you into entering it into a phishing site. Here, the drop-down arrangement of entering three random digits from the six-digit PIN might provide some modest benefit in some scenarios. Many modern keyloggers will take screenshots of the mouse cursor every time the user clicks something, but some simpler/more rudimentary malware still sticks to capturing only keystrokes. Regarding theft of the PIN via phishing...well, here there's even less utility provided, simply because needing to input three randomly selected digits out of a PIN comprised of *only six digits* usually isn't going that imposing a problem. (Again, for reasons others have already well explained.) Still, one could argue that in some scenarios that arrangement may provide some bit (if a small bit) of additional utility vs. simply having the user enter their full PIN each time. (Maybe.)
All of the above being said, using a real two-factor authentication setup would certainly be preferable from a security standpoint. Especially if you're using one-use codes/OTPs generated by a hardware token (most secure) or smartphone authenticator app. No real contest. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | I find it hard to see what security benefits this could provide. In multifactor authentication, the point is to use different factors — i.e., "something you know", "something you have", "something you are". Just repeating the same factor twice seems a bit pointless.
But let me speculate some about what the purpose could be.
**1. Stop keyloggers**
Only dumb malware tries to get passwords by blindly logging key strokes. Requiring the use of a drop down menu may protect against some malware, but in the end trying to hide user input when the computer is already infected is a loosing game. See [this question](https://security.stackexchange.com/questions/127889/whats-the-safest-way-to-enter-information-on-a-website/) for a related discussion. In the end, I think the benefits are small here.
**2. Increase entropy**
If you add a six digit PIN to the password, you get 106 times as many combinations to brute force or almost 20 extra bits of entropy, right? (Or 103 times or 10 bits if you only count the three digits entered.) Yeah, but why not just require a longer password?
Perhaps you want to split it in two to make one part (the PIN) truly random and thereby give protection to users who pick weak passwords. But what does this protect against? For online attacks, you should already have rate limiting in place to deal with this. For offline attacks, you would need to hash the PIN together with the password to get any benefits. But since you can log in providing only three out of six digits they don't seem to be doing this (unless they keep 20 hashes for all possible digit combinations).
**3. Limit the effect of stolen passwords**
Let's say your password gets stolen (say in a phishing attack). If the attack is only performed once, the attacker will only get half of the PIN. She will therefore not be able to easily log in if she is asked for other digits than the ones she got.
I don't see this as a big benefit. Just repeat the attack a couple of times, or attempt to login multiple times (or from different IP's) until you are prompted for the digits you have.
**Drawbacks**
* It makes users more likely to write the PIN (and perhaps the password while they are at it) down on a post it or an email.
* You can not log in using only a password manager. Why make it harder for people who use safe methods to manage their passwords?
**Conclusion**
I can't see any security benefits that would motivate having the user memorise an extra PIN and go through the hassle of picking numbers from drop down menus. To me this smells of [security theater](https://en.wikipedia.org/wiki/Security_theater). But perhaps I am missing something.
*Edit: Yes, I did miss something. See [supercat's answer](https://security.stackexchange.com/a/128670/98538). It's a very good point, but I'm not sure I would think it is worth it anyway.* | The point of [multi-factor authentication](https://en.wikipedia.org/wiki/Multi-factor_authentication) is to require information from multiple sources so that if a user is compromised in one way (say they write their password down somewhere and it's found), then there is still a layer of security preventing account access.
Usually, the three types of authentication information are something you
* **know** - like a password or a pin number you've memorized
* **have** - a phone or some other access token you keep on you
* **are** - a fingerprint or other biometric
Both a password and pin are considered in the first category, so **the pin likely doesn't add much extra security** considering there's a risk that they could both be compromised at the same time (sure, there's no/less risk of keylogging. But what if the information is intercepted over the network or some other form of capture?).
As for advantages, it's hard to say without more information. In this case, it sounds like having a pin is cheaper than doing a "proper" two-factor authentication system. Maybe the threat model is keyloggers on user computers, and this *might* be an appropriate fix. |
128,667 | I would like to ask about this encryption
method that I found: [USPTO patent](http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=Unsene&OS=Unsene&RS=Unsene) and it is related to this question here: [A service that claims beyond army level encryption](https://security.stackexchange.com/questions/51999/a-service-that-claims-beyond-army-level-encryption) and [Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm](https://security.stackexchange.com/questions/101841/unseen-is-encryption-claims-revisited-with-their-proprietary-patented-xaes-al/101868). Didn't see any updates on this matter for a long time, so after I had found the patent had appeared online, wanted to ask you experts what do you think about this? Have we found an quantum computing resistant encryption method for the future generations? Thank you in advance.
Example chapter from the patent documentation:
>
> [0020] While the example above uses the simple Caesar cipher in association with a key for encryption, more complex encryption algorithms such as NTRU, Advanced Encryption Standard (AES), and extended Advanced Encryption Standard (xAES), also use a key as mentioned above in order to encrypt and decrypt data. It should be noted that the encryption algorithm 106 may use any one of these encryption algorithms in accordance with an embodiment of the present invention. The keys associated with these encryption algorithms are significantly more complex than the Caesar cipher and have considerably more characters. Nonetheless, these advanced encryption algorithms use the same principles as the Caesar cipher during encryption and decryption processes. More specifically, each of these encryption algorithms processes data using the encryption algorithm and a key during encryption and decryption. However, the key used with these encryption algorithms have a finite number of bytes. In many instances, these encryption algorithms use a key having 256 bytes, or 32 characters, that are generated using a random number generator. Based on this finite number of keys, unauthorized third parties may correctly guess the key and then, in conjunction with the encryption algorithm, decrypt the encrypted content. In other words, unauthorized third parties may use the key with the encryption algorithms noted above to decrypt encrypted data.
>
>
>
[](https://i.stack.imgur.com/lEQXC.jpg) | 2016/06/29 | [
"https://security.stackexchange.com/questions/128667",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/116093/"
] | A system which locks out an account, even temporarily, in response to invalid password attempts will make it very easy to conduct a denial-of-service attack against someone. Using a two-part authentication makes it possible to have very strict lockout policies on the second part while still remaining resistant to denial-of-service attacks. If someone found out that a person's password on one system was Justin-Bieber, a system with a single part password wouldn't be able to distinguish targeted break-in attempts using variations on that password (e.g. Justin-Bieber1, Justin4Bieber, etc.) from random password entries which are intended to trigger a denial-of-service.
Splitting the password into two parts would mean that an attacker would get notice that the first part was correct *but* the most likely prize would not be access to the account, but merely the ability to trigger a lockdown on it until the real user authenticates via other means; since the user would know that someone else had the primary password, the user would then change that password, rendering it useless. | The point of [multi-factor authentication](https://en.wikipedia.org/wiki/Multi-factor_authentication) is to require information from multiple sources so that if a user is compromised in one way (say they write their password down somewhere and it's found), then there is still a layer of security preventing account access.
Usually, the three types of authentication information are something you
* **know** - like a password or a pin number you've memorized
* **have** - a phone or some other access token you keep on you
* **are** - a fingerprint or other biometric
Both a password and pin are considered in the first category, so **the pin likely doesn't add much extra security** considering there's a risk that they could both be compromised at the same time (sure, there's no/less risk of keylogging. But what if the information is intercepted over the network or some other form of capture?).
As for advantages, it's hard to say without more information. In this case, it sounds like having a pin is cheaper than doing a "proper" two-factor authentication system. Maybe the threat model is keyloggers on user computers, and this *might* be an appropriate fix. |
35,423 | suddenly i cannot select anymore with right click (or example objects in object mode or faces in edit mode). I was doing this tutorial and they asked me to change a few things in user preferences and now i cannot select anything. | 2015/08/10 | [
"https://blender.stackexchange.com/questions/35423",
"https://blender.stackexchange.com",
"https://blender.stackexchange.com/users/-1/"
] | go back to the user preferences, go to input and change select with: to right
[](https://i.stack.imgur.com/WtIwo.jpg) | My RMB on a mac stopped working for selecting, too.
Changing from ortho to perspective view (View:Persp/Ortho) and back again seems to fix the problem.
Loading factory settings didn't help. I could select from the outliner, but not with a RMB click on objects. It would work on a new document, but not my saved document though. This happened several times. Anyone else experience this issue? |
35,423 | suddenly i cannot select anymore with right click (or example objects in object mode or faces in edit mode). I was doing this tutorial and they asked me to change a few things in user preferences and now i cannot select anything. | 2015/08/10 | [
"https://blender.stackexchange.com/questions/35423",
"https://blender.stackexchange.com",
"https://blender.stackexchange.com/users/-1/"
] | go back to the user preferences, go to input and change select with: to right
[](https://i.stack.imgur.com/WtIwo.jpg) | Hit similar issue and since this page is first on Google - leaving answer.
Problem:
- MacOs
- Blender 2.79
- Right button works in outliner, but NOT 3D view
Solution:
- change camera near clip distance to some low value and then back
Suddenly right click started to work as usual |
35,423 | suddenly i cannot select anymore with right click (or example objects in object mode or faces in edit mode). I was doing this tutorial and they asked me to change a few things in user preferences and now i cannot select anything. | 2015/08/10 | [
"https://blender.stackexchange.com/questions/35423",
"https://blender.stackexchange.com",
"https://blender.stackexchange.com/users/-1/"
] | Eventually you may try to ***Load Factory Settings***. It'll restore your RMB click functionality, but also change all your current settings. Make sure to save your work first though.
[](https://i.stack.imgur.com/THEM1.jpg) | My RMB on a mac stopped working for selecting, too.
Changing from ortho to perspective view (View:Persp/Ortho) and back again seems to fix the problem.
Loading factory settings didn't help. I could select from the outliner, but not with a RMB click on objects. It would work on a new document, but not my saved document though. This happened several times. Anyone else experience this issue? |
35,423 | suddenly i cannot select anymore with right click (or example objects in object mode or faces in edit mode). I was doing this tutorial and they asked me to change a few things in user preferences and now i cannot select anything. | 2015/08/10 | [
"https://blender.stackexchange.com/questions/35423",
"https://blender.stackexchange.com",
"https://blender.stackexchange.com/users/-1/"
] | Eventually you may try to ***Load Factory Settings***. It'll restore your RMB click functionality, but also change all your current settings. Make sure to save your work first though.
[](https://i.stack.imgur.com/THEM1.jpg) | Hit similar issue and since this page is first on Google - leaving answer.
Problem:
- MacOs
- Blender 2.79
- Right button works in outliner, but NOT 3D view
Solution:
- change camera near clip distance to some low value and then back
Suddenly right click started to work as usual |
38,842 | Let's consider DCR-97, HMSS Liberty, 300 kilotonnes (or 300 Gg) of dreadnought-carrier ship. It's a big one.
Let's say it can move forward. Let's say it could potentially move backward, or at the very least slow down. Now it would be top if it could just steer left/right/up/down without gravity-assist.
How do I accomplish that?
So we're on the same page: I guess "attitude control" is a more descriptive term than "steering", so strike any mention of steering and replace it. The question is indeed about changing the *direction the ship is pointing*, not the direction the ship is moving.
I'm aware of RCS though I don't know if it applies to such an heavy warship. I've heard of gyroscopic wheels, though once again, I don't know much beyond basic principle.
Requirements: Attitude control should be able to rotate the ship in any of the 3 axes in place if the ship is not moving (i.e. when docking). If the ship is moving, there is no hard requirements on turning radius, I'd just like to be able to turn left before the end of the solar system is all.
Don't forget fuel requirements if applicable.
Attitude control can also help propulsion in translation, though it isn't obligatory. | 2016/03/25 | [
"https://worldbuilding.stackexchange.com/questions/38842",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/18896/"
] | How are you making it move forward? You mean *accelerate*, as movement is relative. You steer by directing the thrust. No kind of rudder will work in a vacuum. You ought to look at information on real spaceships.
Whatever you are doing to make the ship *go*, you do that off-center to apply torque as well. Normally we are talking about rockets of some kind.
Your sci-fi ship will need some enormous power source to make it accelerate. So it will easily have enough power to feed little steering thrusters studding the ends. If you have a made-up drive mechanism, use a litte bit of the *same thing* to turn.
You may have trouble with the particular design; e.g. if the main drive is a high-tech fusion reactor, but it's not practical to make tiny ones studding the exterior for turning in place, and might not be able to vector the thrust of the main drive. Yet, such a heavy ship would have trouble using "simple" chemical rockets or compressed air for the purpose. Perhaps the main drive, when in operation, is used to store energy somehow, and use that to accelerate reaction mass (which still becomes a consumable to ration). You might use water for reaction mass, and produce hydrogen and oxygen from main drive power, using that as rocket fuel when maneuvering thrusters are needed.
As with modern satellites, using a [flywheel](https://en.wikipedia.org/wiki/Reaction_wheel) saves on consumable reaction mass. But it might have to be highly advanced to handle the *amount* of angular momentum necessary. Perhaps parts of the ship's mass that are used for necessary purposes (bulk stores, for example) might move relative to the rest of the ship.
---
If you are asking how to control the orientation of a massive object in space, you have two choices:
* apply thrust off center, thus producing torque. To ensure you don't apply unwanted translation as well, use pairs of thrusters on opposite sides.
* have a way to store angular momentum and transfer it between storage and the main body. This is done with heavy reaction wheels.
Real spacecraft that need to carefully control their orientation, like communication satellites and observation instruments, use both: the wheels have the advantage of full-time careful control without using up anything. But if corrections tend to be in one direction they eventually get "full" and rockets are used to perform the "momentum dump" of the reaction wheels.
It is also possible to use *outside* forces to your advantage. Spacecraft have used solar light pressure to stabilize an orientation and kill unwanted rotation. For a *huge* ship, sunlight would have little effect unless it was using something like a solar sail. | It depends on your main engine technology, since a good option is to use the same engine you use to go forward. You have the additional problem that in space rotating the ship is only half of the problem.
So if you use a thruster as main engine (think Galactica) you use RCS. If you use a field like Star Trek, you manipulate the field in some way to change direction. |
38,842 | Let's consider DCR-97, HMSS Liberty, 300 kilotonnes (or 300 Gg) of dreadnought-carrier ship. It's a big one.
Let's say it can move forward. Let's say it could potentially move backward, or at the very least slow down. Now it would be top if it could just steer left/right/up/down without gravity-assist.
How do I accomplish that?
So we're on the same page: I guess "attitude control" is a more descriptive term than "steering", so strike any mention of steering and replace it. The question is indeed about changing the *direction the ship is pointing*, not the direction the ship is moving.
I'm aware of RCS though I don't know if it applies to such an heavy warship. I've heard of gyroscopic wheels, though once again, I don't know much beyond basic principle.
Requirements: Attitude control should be able to rotate the ship in any of the 3 axes in place if the ship is not moving (i.e. when docking). If the ship is moving, there is no hard requirements on turning radius, I'd just like to be able to turn left before the end of the solar system is all.
Don't forget fuel requirements if applicable.
Attitude control can also help propulsion in translation, though it isn't obligatory. | 2016/03/25 | [
"https://worldbuilding.stackexchange.com/questions/38842",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/18896/"
] | How are you making it move forward? You mean *accelerate*, as movement is relative. You steer by directing the thrust. No kind of rudder will work in a vacuum. You ought to look at information on real spaceships.
Whatever you are doing to make the ship *go*, you do that off-center to apply torque as well. Normally we are talking about rockets of some kind.
Your sci-fi ship will need some enormous power source to make it accelerate. So it will easily have enough power to feed little steering thrusters studding the ends. If you have a made-up drive mechanism, use a litte bit of the *same thing* to turn.
You may have trouble with the particular design; e.g. if the main drive is a high-tech fusion reactor, but it's not practical to make tiny ones studding the exterior for turning in place, and might not be able to vector the thrust of the main drive. Yet, such a heavy ship would have trouble using "simple" chemical rockets or compressed air for the purpose. Perhaps the main drive, when in operation, is used to store energy somehow, and use that to accelerate reaction mass (which still becomes a consumable to ration). You might use water for reaction mass, and produce hydrogen and oxygen from main drive power, using that as rocket fuel when maneuvering thrusters are needed.
As with modern satellites, using a [flywheel](https://en.wikipedia.org/wiki/Reaction_wheel) saves on consumable reaction mass. But it might have to be highly advanced to handle the *amount* of angular momentum necessary. Perhaps parts of the ship's mass that are used for necessary purposes (bulk stores, for example) might move relative to the rest of the ship.
---
If you are asking how to control the orientation of a massive object in space, you have two choices:
* apply thrust off center, thus producing torque. To ensure you don't apply unwanted translation as well, use pairs of thrusters on opposite sides.
* have a way to store angular momentum and transfer it between storage and the main body. This is done with heavy reaction wheels.
Real spacecraft that need to carefully control their orientation, like communication satellites and observation instruments, use both: the wheels have the advantage of full-time careful control without using up anything. But if corrections tend to be in one direction they eventually get "full" and rockets are used to perform the "momentum dump" of the reaction wheels.
It is also possible to use *outside* forces to your advantage. Spacecraft have used solar light pressure to stabilize an orientation and kill unwanted rotation. For a *huge* ship, sunlight would have little effect unless it was using something like a solar sail. | I think that to change the direction which your ship is facing to, you would need a massive RCS system. And lots of time, of course; unless you want to risk extreme G-Forces, rotating the ship backwards could probably even take days.
If you have some sort of G-Force dampers like the Starfleet uses, rotating the ship should be easier. |
38,842 | Let's consider DCR-97, HMSS Liberty, 300 kilotonnes (or 300 Gg) of dreadnought-carrier ship. It's a big one.
Let's say it can move forward. Let's say it could potentially move backward, or at the very least slow down. Now it would be top if it could just steer left/right/up/down without gravity-assist.
How do I accomplish that?
So we're on the same page: I guess "attitude control" is a more descriptive term than "steering", so strike any mention of steering and replace it. The question is indeed about changing the *direction the ship is pointing*, not the direction the ship is moving.
I'm aware of RCS though I don't know if it applies to such an heavy warship. I've heard of gyroscopic wheels, though once again, I don't know much beyond basic principle.
Requirements: Attitude control should be able to rotate the ship in any of the 3 axes in place if the ship is not moving (i.e. when docking). If the ship is moving, there is no hard requirements on turning radius, I'd just like to be able to turn left before the end of the solar system is all.
Don't forget fuel requirements if applicable.
Attitude control can also help propulsion in translation, though it isn't obligatory. | 2016/03/25 | [
"https://worldbuilding.stackexchange.com/questions/38842",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/18896/"
] | **To turn is to accelerate**, but it's rotational acceleration not linear.
As I'm sure you're aware, momentum is conserved. Angular momentum is also conserved, this is what you're dealing with when you turn in space. Your manoeuvring thrusters must not only be able to start the turning motion but also to stop it.
Your thrusters will need to be matched 4s. Symmetrically placed around the centre of mass.
You'll need three sets: Pitch, yaw and roll.
[](https://i.stack.imgur.com/TT797.jpg)
x-axis being "forward"
They should be applied in pairs, one forward one aft for pitch and yaw or one top one bottom for roll, to turn about the centre of mass. However if you pair them same side you could "sidestep". | It depends on your main engine technology, since a good option is to use the same engine you use to go forward. You have the additional problem that in space rotating the ship is only half of the problem.
So if you use a thruster as main engine (think Galactica) you use RCS. If you use a field like Star Trek, you manipulate the field in some way to change direction. |
38,842 | Let's consider DCR-97, HMSS Liberty, 300 kilotonnes (or 300 Gg) of dreadnought-carrier ship. It's a big one.
Let's say it can move forward. Let's say it could potentially move backward, or at the very least slow down. Now it would be top if it could just steer left/right/up/down without gravity-assist.
How do I accomplish that?
So we're on the same page: I guess "attitude control" is a more descriptive term than "steering", so strike any mention of steering and replace it. The question is indeed about changing the *direction the ship is pointing*, not the direction the ship is moving.
I'm aware of RCS though I don't know if it applies to such an heavy warship. I've heard of gyroscopic wheels, though once again, I don't know much beyond basic principle.
Requirements: Attitude control should be able to rotate the ship in any of the 3 axes in place if the ship is not moving (i.e. when docking). If the ship is moving, there is no hard requirements on turning radius, I'd just like to be able to turn left before the end of the solar system is all.
Don't forget fuel requirements if applicable.
Attitude control can also help propulsion in translation, though it isn't obligatory. | 2016/03/25 | [
"https://worldbuilding.stackexchange.com/questions/38842",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/18896/"
] | ### Orientation != Velocity Vector != Acceleration Vector
To ensure there's no ambiguity here.
In spacecraft, the direction that the ship is facing is not necessarily the direction in which the ship is moving (but if the ship is accelerating, it usually is the direction in which acceleration is occurring).
Similarly, the direction in which the ship is moving is not necessarily the direction in which the ship is accelerating or facing.
### Ship Velocity Vector can be changed without thrusting
But it still requires a momentum exchange with something.
A maneuver typical of this operation is called a gravity assist. The net result of a gravity assist changes the velocity of the ship relative to a third object (e.g. the Sun) but not the body performing the assist (e.g. Jupiter).
### What exactly are you asking?
From your question and the comments, I think you want to know how to change spacecraft orientation (not velocity or acceleration vectors), without firing your engines.
If this is your question, then the answer is there are [many methods of changing spacecraft orientation](https://en.wikipedia.org/wiki/Attitude_control#Actuators) without (directly) affecting the spacecraft velocity and acceleration vectors.
Attitude Control:
1. Thrusters / RCS
2. Spin stabilization (this doesn't help you change orientation but it helps the spacecraft maintain a desired orientation).
3. Momentum wheels (these are not gyroscopes)
4. Control moment gyros (these are not moment wheels)
5. Solar sails (and/or magnetic sails and/or Solar wind sails)
6. Gravity-gradient stabilization (only appropriate when in orbit)
7. Magnetic torquers (only appropriate when in a relatively strong magnetic field - this is not a magsail)
8. Pure passive attitude control (gravity-gradient is one such passive attitude control, but there are others).
9. Off center of mass thrusting (gimbal mounted engine or exhaust vane directed thrust)
This is complicated by the fact that every spacecraft ever designed has its main engine thrusting through the center of gravity.
So if you change a ships orientation while it is thrusting, you will change both its acceleration and velocity vectors.
### There is no "turning radius" for spacecraft
Or more precisely the turning radius depends upon your current velocity and your thrust capabilities.
Forget 99.999% of everything you've ever seen about how objects move in space. Anything you've seen in movies or TV are wrong (and this includes supposedly accurate movies like **Gravity** - don't get me started).
Application of a thrust:
[](https://i.stack.imgur.com/bLDVx.png)
Other than the fact that usually the application of thrust is in the direction the craft is oriented, space craft velocity has nothing to do with spacecraft orientation.
Suggested solution
------------------
You will probably require multiple attitude control systems. At least one of these will be a system that requires no fuel and little power. At least one of these will involve off-CG axis thrusting by your main propulsion system. The third will likely be a thrusting, reaction control system.
Since you're already aware of RCS, let's look at CMG (control moment gyros).
### [Control Moment Gyros](https://en.wikipedia.org/wiki/Control_moment_gyroscope)
A CMG can apply the large amounts of torque required to change the orientation of your ship. It also doesn't use much power to do it. However, CMGs have a draw back:
>
> At least three single-axis CMGs are necessary for control of
> spacecraft attitude. However, no matter how many CMGs a spacecraft
> uses, gimbal motion can lead to relative orientations that produce no
> usable output torque along certain directions.
>
>
>
Meaning there are some orientation changes you can not do using only CMGs. To get around this limitation, a CMG attitude control system must use something like RCS.
### Off-CG axis thrusting
Will impart rotation upon the spacecraft. By simply changing engine orientation you can cancel this rotation at any time you desire. The draw back is this is only available when firing your main engine. It will also change your velocity vector. | It depends on your main engine technology, since a good option is to use the same engine you use to go forward. You have the additional problem that in space rotating the ship is only half of the problem.
So if you use a thruster as main engine (think Galactica) you use RCS. If you use a field like Star Trek, you manipulate the field in some way to change direction. |
38,842 | Let's consider DCR-97, HMSS Liberty, 300 kilotonnes (or 300 Gg) of dreadnought-carrier ship. It's a big one.
Let's say it can move forward. Let's say it could potentially move backward, or at the very least slow down. Now it would be top if it could just steer left/right/up/down without gravity-assist.
How do I accomplish that?
So we're on the same page: I guess "attitude control" is a more descriptive term than "steering", so strike any mention of steering and replace it. The question is indeed about changing the *direction the ship is pointing*, not the direction the ship is moving.
I'm aware of RCS though I don't know if it applies to such an heavy warship. I've heard of gyroscopic wheels, though once again, I don't know much beyond basic principle.
Requirements: Attitude control should be able to rotate the ship in any of the 3 axes in place if the ship is not moving (i.e. when docking). If the ship is moving, there is no hard requirements on turning radius, I'd just like to be able to turn left before the end of the solar system is all.
Don't forget fuel requirements if applicable.
Attitude control can also help propulsion in translation, though it isn't obligatory. | 2016/03/25 | [
"https://worldbuilding.stackexchange.com/questions/38842",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/18896/"
] | **To turn is to accelerate**, but it's rotational acceleration not linear.
As I'm sure you're aware, momentum is conserved. Angular momentum is also conserved, this is what you're dealing with when you turn in space. Your manoeuvring thrusters must not only be able to start the turning motion but also to stop it.
Your thrusters will need to be matched 4s. Symmetrically placed around the centre of mass.
You'll need three sets: Pitch, yaw and roll.
[](https://i.stack.imgur.com/TT797.jpg)
x-axis being "forward"
They should be applied in pairs, one forward one aft for pitch and yaw or one top one bottom for roll, to turn about the centre of mass. However if you pair them same side you could "sidestep". | I think that to change the direction which your ship is facing to, you would need a massive RCS system. And lots of time, of course; unless you want to risk extreme G-Forces, rotating the ship backwards could probably even take days.
If you have some sort of G-Force dampers like the Starfleet uses, rotating the ship should be easier. |
38,842 | Let's consider DCR-97, HMSS Liberty, 300 kilotonnes (or 300 Gg) of dreadnought-carrier ship. It's a big one.
Let's say it can move forward. Let's say it could potentially move backward, or at the very least slow down. Now it would be top if it could just steer left/right/up/down without gravity-assist.
How do I accomplish that?
So we're on the same page: I guess "attitude control" is a more descriptive term than "steering", so strike any mention of steering and replace it. The question is indeed about changing the *direction the ship is pointing*, not the direction the ship is moving.
I'm aware of RCS though I don't know if it applies to such an heavy warship. I've heard of gyroscopic wheels, though once again, I don't know much beyond basic principle.
Requirements: Attitude control should be able to rotate the ship in any of the 3 axes in place if the ship is not moving (i.e. when docking). If the ship is moving, there is no hard requirements on turning radius, I'd just like to be able to turn left before the end of the solar system is all.
Don't forget fuel requirements if applicable.
Attitude control can also help propulsion in translation, though it isn't obligatory. | 2016/03/25 | [
"https://worldbuilding.stackexchange.com/questions/38842",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/18896/"
] | ### Orientation != Velocity Vector != Acceleration Vector
To ensure there's no ambiguity here.
In spacecraft, the direction that the ship is facing is not necessarily the direction in which the ship is moving (but if the ship is accelerating, it usually is the direction in which acceleration is occurring).
Similarly, the direction in which the ship is moving is not necessarily the direction in which the ship is accelerating or facing.
### Ship Velocity Vector can be changed without thrusting
But it still requires a momentum exchange with something.
A maneuver typical of this operation is called a gravity assist. The net result of a gravity assist changes the velocity of the ship relative to a third object (e.g. the Sun) but not the body performing the assist (e.g. Jupiter).
### What exactly are you asking?
From your question and the comments, I think you want to know how to change spacecraft orientation (not velocity or acceleration vectors), without firing your engines.
If this is your question, then the answer is there are [many methods of changing spacecraft orientation](https://en.wikipedia.org/wiki/Attitude_control#Actuators) without (directly) affecting the spacecraft velocity and acceleration vectors.
Attitude Control:
1. Thrusters / RCS
2. Spin stabilization (this doesn't help you change orientation but it helps the spacecraft maintain a desired orientation).
3. Momentum wheels (these are not gyroscopes)
4. Control moment gyros (these are not moment wheels)
5. Solar sails (and/or magnetic sails and/or Solar wind sails)
6. Gravity-gradient stabilization (only appropriate when in orbit)
7. Magnetic torquers (only appropriate when in a relatively strong magnetic field - this is not a magsail)
8. Pure passive attitude control (gravity-gradient is one such passive attitude control, but there are others).
9. Off center of mass thrusting (gimbal mounted engine or exhaust vane directed thrust)
This is complicated by the fact that every spacecraft ever designed has its main engine thrusting through the center of gravity.
So if you change a ships orientation while it is thrusting, you will change both its acceleration and velocity vectors.
### There is no "turning radius" for spacecraft
Or more precisely the turning radius depends upon your current velocity and your thrust capabilities.
Forget 99.999% of everything you've ever seen about how objects move in space. Anything you've seen in movies or TV are wrong (and this includes supposedly accurate movies like **Gravity** - don't get me started).
Application of a thrust:
[](https://i.stack.imgur.com/bLDVx.png)
Other than the fact that usually the application of thrust is in the direction the craft is oriented, space craft velocity has nothing to do with spacecraft orientation.
Suggested solution
------------------
You will probably require multiple attitude control systems. At least one of these will be a system that requires no fuel and little power. At least one of these will involve off-CG axis thrusting by your main propulsion system. The third will likely be a thrusting, reaction control system.
Since you're already aware of RCS, let's look at CMG (control moment gyros).
### [Control Moment Gyros](https://en.wikipedia.org/wiki/Control_moment_gyroscope)
A CMG can apply the large amounts of torque required to change the orientation of your ship. It also doesn't use much power to do it. However, CMGs have a draw back:
>
> At least three single-axis CMGs are necessary for control of
> spacecraft attitude. However, no matter how many CMGs a spacecraft
> uses, gimbal motion can lead to relative orientations that produce no
> usable output torque along certain directions.
>
>
>
Meaning there are some orientation changes you can not do using only CMGs. To get around this limitation, a CMG attitude control system must use something like RCS.
### Off-CG axis thrusting
Will impart rotation upon the spacecraft. By simply changing engine orientation you can cancel this rotation at any time you desire. The draw back is this is only available when firing your main engine. It will also change your velocity vector. | I think that to change the direction which your ship is facing to, you would need a massive RCS system. And lots of time, of course; unless you want to risk extreme G-Forces, rotating the ship backwards could probably even take days.
If you have some sort of G-Force dampers like the Starfleet uses, rotating the ship should be easier. |
128,277 | I'm a new member making my first post here. I had a very quick, and admittedly basic, question. I'm setting up an info sec lab for the first time at home. I'm trying to build some more technical skills with things like Kali linux, pfsense, etc to help me transition from help desk/desktop support to a security analyst (or similar) role.
Just wanted to see if it was reasonably safe to put my host OS on my home wifi network? My understanding of VMs is that I can network them directly to each other and not expose them to the Internet. If that is the case, is it still necessary to put the host OS on its own network as well, or am I safe to leave it on the home network?
I was trying to see if my router (Verizon Actiontec) would allow for VLANs, but as far as I can tell, that is not the case. From what I've read so far, if I wanted to segregate my lab PC from my home wifi network, I'd need to purchase a second router. But if that's not necessary, and its safe to leave the host OS on my home network, I'll do so.
I very appreciate your time and feedback on this question and helping me to better understand. Thank you! | 2016/06/25 | [
"https://security.stackexchange.com/questions/128277",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/115576/"
] | It sounds like you are trying to setup something of a cyber-range for learning. If this is the case you simply need to understand what risks are and are not being added to your network. Are you trying to make these systems available to the Internet as a whole ? If so, then you are adding very different risks than if they can only be accessed internally.
Likewise are you using this to test malware or play with botnets ? Systems for experimenting with these will have entirely different risks.
In any of these situations you are increasing the level of risk to your other home systems but if you are just setting up a cyber-range that cannot be accessed from the Internet it seems like it may be a reasonable risk for the amount of experience you will gain.
Your question doesn't have enough detail for anyone to really help you evaluate the risks but I think this also makes for a great learning experience for you too. What do you think of the risks and how would you learn to evaluate them. Evaluating risks is a big part of helping organizations with their security so maybe this is a great time to consider all aspects of what risks you are changing in your home network and also think about other things you can do to mitigate those risks. Maybe consider increasing the security of the other devices, backing up more often, and setup some type of network monitoring if you can. Again it depends on what your concerns are.
As a side note many security professionals do have two or more networks at home for this type thing and there are a lot of ways to do it. Likewise VM's can be very useful for creating cyber-ranges and cloud computing resources can be a helpful inexpensive solution for many types of tests (especially something like Amazon AWS where you can use a resource for just a few hours as needed).
My suggestion is if you're not dealing with malware or anything explicitly malicious go ahead and dive in. **Some of the mistakes you will make will provide your best learning experiences and the faster you make those mistakes the quicker you'll learn their lessons.** | It ultimately depends on your threat model and what exactly you will be doing, but I see no problem having the host machine on your home network, especially if the VMs are on their own, isolated network. Even then, unless you are releasing malware into this network, I can't imagine the existence your test environment would pose much of a threat to your home network.
You may even want to provide some internet access to the environment for installing/updating packages and such. |
128,277 | I'm a new member making my first post here. I had a very quick, and admittedly basic, question. I'm setting up an info sec lab for the first time at home. I'm trying to build some more technical skills with things like Kali linux, pfsense, etc to help me transition from help desk/desktop support to a security analyst (or similar) role.
Just wanted to see if it was reasonably safe to put my host OS on my home wifi network? My understanding of VMs is that I can network them directly to each other and not expose them to the Internet. If that is the case, is it still necessary to put the host OS on its own network as well, or am I safe to leave it on the home network?
I was trying to see if my router (Verizon Actiontec) would allow for VLANs, but as far as I can tell, that is not the case. From what I've read so far, if I wanted to segregate my lab PC from my home wifi network, I'd need to purchase a second router. But if that's not necessary, and its safe to leave the host OS on my home network, I'll do so.
I very appreciate your time and feedback on this question and helping me to better understand. Thank you! | 2016/06/25 | [
"https://security.stackexchange.com/questions/128277",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/115576/"
] | It sounds like you are trying to setup something of a cyber-range for learning. If this is the case you simply need to understand what risks are and are not being added to your network. Are you trying to make these systems available to the Internet as a whole ? If so, then you are adding very different risks than if they can only be accessed internally.
Likewise are you using this to test malware or play with botnets ? Systems for experimenting with these will have entirely different risks.
In any of these situations you are increasing the level of risk to your other home systems but if you are just setting up a cyber-range that cannot be accessed from the Internet it seems like it may be a reasonable risk for the amount of experience you will gain.
Your question doesn't have enough detail for anyone to really help you evaluate the risks but I think this also makes for a great learning experience for you too. What do you think of the risks and how would you learn to evaluate them. Evaluating risks is a big part of helping organizations with their security so maybe this is a great time to consider all aspects of what risks you are changing in your home network and also think about other things you can do to mitigate those risks. Maybe consider increasing the security of the other devices, backing up more often, and setup some type of network monitoring if you can. Again it depends on what your concerns are.
As a side note many security professionals do have two or more networks at home for this type thing and there are a lot of ways to do it. Likewise VM's can be very useful for creating cyber-ranges and cloud computing resources can be a helpful inexpensive solution for many types of tests (especially something like Amazon AWS where you can use a resource for just a few hours as needed).
My suggestion is if you're not dealing with malware or anything explicitly malicious go ahead and dive in. **Some of the mistakes you will make will provide your best learning experiences and the faster you make those mistakes the quicker you'll learn their lessons.** | Its easy buddy. Get yourself a new standalone PC that you aren't using for anything else (craigslist comes highly recommended).
From there, get software that will run your virtual machines, e.g. qemu, [virtualbox](https://www.virtualbox.org/wiki/Downloads), [VMWare Player](https://www.vmware.com/go/downloadplayer), etc.
For your attacking machine, [Kali Linux](https://www.kali.org/downloads/) comes ***highly*** recommended.
For the VM to attack, you should download preloaded VM images such as [DVWA](http://www.dvwa.co.uk/), anything from [Vulnhub](https://vulnhub.com), etc. |
128,277 | I'm a new member making my first post here. I had a very quick, and admittedly basic, question. I'm setting up an info sec lab for the first time at home. I'm trying to build some more technical skills with things like Kali linux, pfsense, etc to help me transition from help desk/desktop support to a security analyst (or similar) role.
Just wanted to see if it was reasonably safe to put my host OS on my home wifi network? My understanding of VMs is that I can network them directly to each other and not expose them to the Internet. If that is the case, is it still necessary to put the host OS on its own network as well, or am I safe to leave it on the home network?
I was trying to see if my router (Verizon Actiontec) would allow for VLANs, but as far as I can tell, that is not the case. From what I've read so far, if I wanted to segregate my lab PC from my home wifi network, I'd need to purchase a second router. But if that's not necessary, and its safe to leave the host OS on my home network, I'll do so.
I very appreciate your time and feedback on this question and helping me to better understand. Thank you! | 2016/06/25 | [
"https://security.stackexchange.com/questions/128277",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/115576/"
] | It sounds like you are trying to setup something of a cyber-range for learning. If this is the case you simply need to understand what risks are and are not being added to your network. Are you trying to make these systems available to the Internet as a whole ? If so, then you are adding very different risks than if they can only be accessed internally.
Likewise are you using this to test malware or play with botnets ? Systems for experimenting with these will have entirely different risks.
In any of these situations you are increasing the level of risk to your other home systems but if you are just setting up a cyber-range that cannot be accessed from the Internet it seems like it may be a reasonable risk for the amount of experience you will gain.
Your question doesn't have enough detail for anyone to really help you evaluate the risks but I think this also makes for a great learning experience for you too. What do you think of the risks and how would you learn to evaluate them. Evaluating risks is a big part of helping organizations with their security so maybe this is a great time to consider all aspects of what risks you are changing in your home network and also think about other things you can do to mitigate those risks. Maybe consider increasing the security of the other devices, backing up more often, and setup some type of network monitoring if you can. Again it depends on what your concerns are.
As a side note many security professionals do have two or more networks at home for this type thing and there are a lot of ways to do it. Likewise VM's can be very useful for creating cyber-ranges and cloud computing resources can be a helpful inexpensive solution for many types of tests (especially something like Amazon AWS where you can use a resource for just a few hours as needed).
My suggestion is if you're not dealing with malware or anything explicitly malicious go ahead and dive in. **Some of the mistakes you will make will provide your best learning experiences and the faster you make those mistakes the quicker you'll learn their lessons.** | I've got the same situation. I'm currently running Window 7 as my main OS. So what i did is that i installed Windows 2012 R2 trial on another HDD - low RAM usage, free Hyper-V etc.
**Then i created my "SecLab" how i call it in Hyper-V.**
--------------------------------------------------------
I am running 5 VMs in Hyper-V:
1. Kali Linux
2. Windows 7(Trial)
3. Windows 8.1(Trial)
4. Windows 2012 R2(Trial)
5. Windows 2008 R2(Trial)
**It is really important to hook them to virtual switch**(virtual network where VMs can communicate with each other but not really outside the network - only VM with VM. Nothing else outside this network) to prevent possible damage.
Now you've got OSes to try your hacks on and pretty much secure lab.
**TL;DR** You've got your second OS(Win 2012) which has connection to internet and so, and is running 5 VMs which are encapsulated within its own network. Everything is safe and the only damage is possible on VMs. |
617,053 | I'm a senior student in high school and we are learning about Particle Physics in Physics. I wanted to ask a question about neutrons. Is there a possibility that neutrons may not even be a particle, just a bond, relationship or pairing between electrons and protons? Can neutrons just be the cancelling out of electrons and protons charges, forming a neutral charge inside the nucleus and not an actual particle? For example, carbon has 6 electrons, 6 protons and 6 neutrons. Could the 6 neutrons and 6 protons cancel each other out forming 6 neutral charges making the atom stable? The protons and electrons would still exist but they just form a stable atom by being neutrally charged. I know this is extremely unlikely and most likely wrong but I really wanted to know if there was an answer to this or is the theory we have have no correct and there is no need for further debate. | 2021/02/25 | [
"https://physics.stackexchange.com/questions/617053",
"https://physics.stackexchange.com",
"https://physics.stackexchange.com/users/290217/"
] | >
> or is the theory we have have no correct and there is no need for further debate.
>
>
>
You are a hundred years too late to be able to play with the models of nuclear physics. Physics reasearch at present has progressed to the level that has shown that protons and neutrons, not only are the two versions of the"same" particle called collectively a [nucleon](https://en.wikipedia.org/wiki/Nucleon) , but also that the nucleons are composites of smaller particles called [quarks](https://en.wikipedia.org/wiki/Quark). There is a lot to study ahead, if you continue your studies. | If I understand your thoughts correctly, and you had a typo when you said "Could the 6 neutrons (you wanted to say electrons) and 6 protons cancel each other", you expected a carbon atom to have the same number of protons and neutrons. If you know that there are carbon 13 (which has 7 neutrons) and carbon 14 (which has 8 neutrons), you may think twice. |
1,367,170 | Have a smartclient application that is distributed using Click-Once, but also includes a SQLite DB for a local cache.
The problems is that once the app is published it doesn't seem to be able to open the SQLite DB file. Have included the DB file as part of the install process...
Any thoughts? | 2009/09/02 | [
"https://Stackoverflow.com/questions/1367170",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/112064/"
] | When a ClickOnce application is set to "Full Trust", on install it will prompt the user to grant full trust. This means that the application will have all the same privileges on the computer as the user running the application (editing the regisitry, file io, etc). You mentioned in the comments that the app is set to full trust, so it would appear that it's not a security issue.
Are you certain *all* of the necessary files are getting deployed? I would just remove ClickOnce from the picture. Look at all the files in your deployment, create a folder and copy all those files into it, then try to run it. Does it work? My initial guess is that some needed file is not being included in the ClickOnce deployment. | Have you included the SQLite provider in the package? |
1,367,170 | Have a smartclient application that is distributed using Click-Once, but also includes a SQLite DB for a local cache.
The problems is that once the app is published it doesn't seem to be able to open the SQLite DB file. Have included the DB file as part of the install process...
Any thoughts? | 2009/09/02 | [
"https://Stackoverflow.com/questions/1367170",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/112064/"
] | Check the path that your app is using to get to the database. Virtuallized paths can cause these sorts of problems on Vista and above.
Then check the read/write permissions on the database file. | Have you included the SQLite provider in the package? |
1,367,170 | Have a smartclient application that is distributed using Click-Once, but also includes a SQLite DB for a local cache.
The problems is that once the app is published it doesn't seem to be able to open the SQLite DB file. Have included the DB file as part of the install process...
Any thoughts? | 2009/09/02 | [
"https://Stackoverflow.com/questions/1367170",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/112064/"
] | When a ClickOnce application is set to "Full Trust", on install it will prompt the user to grant full trust. This means that the application will have all the same privileges on the computer as the user running the application (editing the regisitry, file io, etc). You mentioned in the comments that the app is set to full trust, so it would appear that it's not a security issue.
Are you certain *all* of the necessary files are getting deployed? I would just remove ClickOnce from the picture. Look at all the files in your deployment, create a folder and copy all those files into it, then try to run it. Does it work? My initial guess is that some needed file is not being included in the ClickOnce deployment. | Check the path that your app is using to get to the database. Virtuallized paths can cause these sorts of problems on Vista and above.
Then check the read/write permissions on the database file. |
1,367,170 | Have a smartclient application that is distributed using Click-Once, but also includes a SQLite DB for a local cache.
The problems is that once the app is published it doesn't seem to be able to open the SQLite DB file. Have included the DB file as part of the install process...
Any thoughts? | 2009/09/02 | [
"https://Stackoverflow.com/questions/1367170",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/112064/"
] | When a ClickOnce application is set to "Full Trust", on install it will prompt the user to grant full trust. This means that the application will have all the same privileges on the computer as the user running the application (editing the regisitry, file io, etc). You mentioned in the comments that the app is set to full trust, so it would appear that it's not a security issue.
Are you certain *all* of the necessary files are getting deployed? I would just remove ClickOnce from the picture. Look at all the files in your deployment, create a folder and copy all those files into it, then try to run it. Does it work? My initial guess is that some needed file is not being included in the ClickOnce deployment. | I had a same problem. My solution was to add SQL.interop.DLL (x32 and x64) in the Visual Studio Project (as link) so that the ClickOne Deploiment add those files in this "package"
Look this blog post :
<http://webbercross.azurewebsites.net/ef7-sqlite-click-once-deployment-error/> |
1,367,170 | Have a smartclient application that is distributed using Click-Once, but also includes a SQLite DB for a local cache.
The problems is that once the app is published it doesn't seem to be able to open the SQLite DB file. Have included the DB file as part of the install process...
Any thoughts? | 2009/09/02 | [
"https://Stackoverflow.com/questions/1367170",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/112064/"
] | Check the path that your app is using to get to the database. Virtuallized paths can cause these sorts of problems on Vista and above.
Then check the read/write permissions on the database file. | I had a same problem. My solution was to add SQL.interop.DLL (x32 and x64) in the Visual Studio Project (as link) so that the ClickOne Deploiment add those files in this "package"
Look this blog post :
<http://webbercross.azurewebsites.net/ef7-sqlite-click-once-deployment-error/> |
133,871 | Lost an identity card in 2018 and subsequently got a new one. The old one of course got blocked.
However, when using my new one, an alert pops up referring to the old one, which border control occasionally reacts to (they then normally more or less tell me about it if we have a common language, but it could be the reason for me being held for an hour in Milan recently, under the false pretext of me allegedly not being allowed into Italy passport-free if arriving directly from Ukraine).
According to a specialist at the Swedish police, it's because the systems recognise my name and date of birth, but don't take into consideration the new document number.
Now, I imagine if someone were to find my old ID and copy and sell to an illegal immigrant, they would either copy all the data exactly, or alter all the data.
In what case would they alter the document number but leave the other data intact?
What it boils down to is: why would using my current ID trigger an alert due to my old one?
I don't know if using a passport would have the same effect - I'll reply and ask that after hopefully getting feedback from here. | 2019/03/14 | [
"https://travel.stackexchange.com/questions/133871",
"https://travel.stackexchange.com",
"https://travel.stackexchange.com/users/39782/"
] | So you lost your ID and it’s possible that shady people have learned that a certain person (you) exists and if they were to impersonate someone, they might as well use a real person. However, they’re aware that you’ll apply for a new document and this particular one would become invalid. Thus they could have forged a document with your data but with a fake number and sent someone into Milan from Ukraine for more shady things. Until careful inspection of your document confirms it’s genuine, this hypothetical situation is indistinguishable from what actually happened, thus investigation is warranted. | The document number is checked too. Sometimes an ID card number is linked to a Social Security number therefore the replacement card will have the same number as the lost/stolen card. In those instances the Officer will consider the date of issue of the replacement card to ensure it post dates the reported loss/theft. Sometimes a national ID card will have the same alpha/numeric sequence as another nation's passports, so the Officer will consider the type of document reported lost/stolen and the document being presented. In addition the Officer will question the document holder to allay or confirm suspicions. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | >
> Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
>
>
>
This would depend on the maneuverability of the animal as well as how securely the rider is attached to the mount. Giant Eagles could probably do loop-de-loops, but if the rider is just sitting in a saddle equivalent to a horse's saddle, there's a decent chance he might fall out!
(I'm assuming significant G-forces - the likes of which might make a rider black out - wouldn't come into play, because a giant eagle would be moving more slowly than an airplane, but if I'm wrong, I'm sure someone will correct me.)
**Edit:** As Peter mentions in the comments, some real-life birds have been clocked pulling upwards of 10Gs, so the G-Force issue could be a concern for these riders, subject to the abilities of the mount itself.
>
> How would the military formations be?
>
>
>
Whenever I think of fighting formations in 3D, I think of the video game [Homeworld.](http://homeworld.wikia.com/wiki/Formations) You have your standard "wall" and "sphere" formations, an "arrow-head" formation for breaking enemy formations and a "claw" formation for quickly surrounding outnumbered enemy units. I imagine many of these formations would work well for flying cavalry, with perhaps some tweaking. Sphere, for example, would be better as a defensive formation - protecting the "target" from all sides, rather than surrounding and firing upon an enemy target.
>
> What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
>
>
>
I feel like evasion would be more effective as a defensive measure on flying animals than armor. If ranges are long and speeds high, landing a blow will be hard anyway, and everything you can do to lighten the load on the mount would increase the odds of avoiding incoming fire. Heavy armour would only have real value if the creatures regularly close to melee ranges in order to strike with talons and such.
Regardless of how riders are armoured, the easiest way to take them out of the fight would be to either dismount the rider (so he falls to his death) or to attack the mount and force it to retreat/land. So lances and other long pole-arms would be favoured over swords or axes (as dismounting the rider is easier and more effective than stabbing them until they die in the saddle.)
The mount probably can't fly with too much barding, so bows & arrows could be viable weapons as well - aiming at the mount's wings or face rather than the rider directly. **Flaming arrows** would be doubly effective - not only would the fire damage the mount if it hits, but even a near miss could cause the mount to panic. It might flee the battle regardless of its rider, or make sudden course changes that end up dislodging the rider entirely.
>
> Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
>
>
>
Depends on the range between the city and the battle, of course. I feel like ballistae might be a better fit than catapults in most cases.
If people have access to any kind of explosives, then explosive rounds would obviously be favoured. Fire into a clump of enemy units and aiming becomes much less important (which is important, because aiming at fast-moving flying units over long distances is hard.)
Aside from explosives, flaming ammunition would also be useful, as discussed above. Also, nets. A big net with weights around the edges so it spreads out in flight and has enough inertia to entangle targets and send them plummeting to the ground. Range would be relatively short without some kind of delayed deployment system, but that's up the details of your world, I suppose. | Assuming mounted riders with some sort of harness for stability, I would discount any type of hand held melee weapon or even lances - too much chance of a mid-air between mounts and both sides would go down. You need to use some sort of distance weapon. That said, crossbows are too hard to reload, long bows are too ungainly - a mid size bow might be reasonable. Still, with the air currents your mount, other mounts and the enemy mounts are generating, hits are low probability. An entanglement weapon like a bola might work.
Regarding the citidels, assuming you're using the mount as a bomber (dropping incendiary or explosives) then catapults and arbalests might be like the flak gun of WW2. Load the catapult with shot or even hot shot (getting hit with burning hot rocks - not fun) and if you can - some sort of timed explosive with shrapnel. The arbalests would be nicer with explosives or with some sort of deployed net.
Regarding maneuvers - individual maneuvering is usually for air-to-air combat where hitting the other flyer is the main objective. When bombing, you usually have a set formation with the defensive gunnery hopefully overlapping and interlocking and providing for your defense. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | I would imagine the fights to be more like bird combat than like anything humans have ever done.
Consider for a moment that you are seated on top of a large bird in the manner of a horse. First problem is that the bird would need you to sit near the middle of the wing in order to maintain it's front-rear balance. This means the wings/head/tail are in your way for shooting or lances, unless you're aiming up. Also, you have a 30+mph headwind or so, so archery would require an extreme level of skill.
For physical melee, birds usually gain height and dive into their prey for a beak or talon strike to the exposed back. If the goal were just to have humans guide the bird's attacks, then the bird would probably gain height then try to dive from above. I would think that strategy would always be about trying to get the upper positioning on an opponent. There might be coordinated strategies where they try to bait upper enemies into dives, then dodge, leaving the enemy at a lower altitude afterward. If one or two fighters bait the enemy well, it could leave many enemies at a lower altitude so that allies can then attack them from above.
Another thing to consider is weight. The animal with the least extra weight will have the best maneuverability and ability to gain altitude. Since the rider isn't using strength, I think you'd end up in a horse racing situation where the smallest lightest jockeys win the most. It could even be a job for children. But on the topic of gaining altitude, birds do this by circling in thermals (hot air that naturally lifts them upward, saving the very great effort of flapping their wings). So then, thermals will be a strategic feature of the battleground, which both sides would seek to control. Whoever is highest in the thermal would have the best ability to strike those below, and also re-gain altitude afterward if their side maintains control of the thermal.
And finally, you have to consider what their goal is if the enemy air force is defeated. Recon was a good enough reason in WWI, but if you want this to be a long-running technology then they will probably have moved to things like dropping burning pitch on enemy structures or something. I would imagine that smaller lighter "fighters" would guard the more encumbered "bombers" in much the same way that the modern airforce does, simply because an encumbered bird can't do much in an air-fight, and an un-equipped bird can't do much against ground targets.
For a final image of all this, imagine that you have the pilot hanging from straps *under* the bird, able to see where they're going easily and fire a crossbow at lower targets or pull a pin to drop burning pitch, while a child rides on top facing backward with a crossbow to defend the bird from attacks from above/behind. The crossbow would be for last-second counters against an incoming dive, and not for long-range attack. The squadron sends the fastest fliers out first to find the thermals, gain altitude, and defend them as the rest of the fighters reach the thermal, while the "bombers" follow a bit later (once they determine the skies are under control) to make a direct route for enemy targets before they get tired or the pitch cools off. The bombers have to maintain high enough altitude to not get hit by arrows from the ground, but low enough to actually hit their targets.
Update
------
Thinking more on this, the under-pilot and rear-gunner configuration I described might be ok for a "bomber", but if the animals are in fact coming into contact then a lance might still be a useful weapon. Also a single-person configuration would be ideal for the fighter role. But, I still think a saddle/sitting position is unlikely to work. However, if the pilot were to lay flat on the back of the mount, then their weight would be relatively centered while still being able to look over the wing and see below. Also much more aerodynamic this way. There might be a strap-based harness that allows the pilot to flip over onto his back to watch for attacks from above/behind, and then there could be lances mounted to the bird and trailing in the wind which the pilot would grab and aim in the event of an attack. If the attacker didn't abort the dive or dodge, the enemy mount would be impaled while the defending mount would just be knocked downward a few hundred feet as the pilot either frees or discards the lance. This would change dives from a standard attack to more of a surprise/opportunistic attack if they thought the other pilot wasn't going to be able to ready a lance in time. (or if he runs out of lances) Crossbow would probably still be a useful weapon, but now that the pilot is handling multiple weapons and laying down it might need to be tethered to their shoulder or something.
* [Peregrine Falcon dive attack](https://youtu.be/Hpz66RYD110)
* [Mid-air eagle fight](https://youtu.be/tufnqWNP9AA?t=48) | >
> Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
>
>
>
This would depend on the maneuverability of the animal as well as how securely the rider is attached to the mount. Giant Eagles could probably do loop-de-loops, but if the rider is just sitting in a saddle equivalent to a horse's saddle, there's a decent chance he might fall out!
(I'm assuming significant G-forces - the likes of which might make a rider black out - wouldn't come into play, because a giant eagle would be moving more slowly than an airplane, but if I'm wrong, I'm sure someone will correct me.)
**Edit:** As Peter mentions in the comments, some real-life birds have been clocked pulling upwards of 10Gs, so the G-Force issue could be a concern for these riders, subject to the abilities of the mount itself.
>
> How would the military formations be?
>
>
>
Whenever I think of fighting formations in 3D, I think of the video game [Homeworld.](http://homeworld.wikia.com/wiki/Formations) You have your standard "wall" and "sphere" formations, an "arrow-head" formation for breaking enemy formations and a "claw" formation for quickly surrounding outnumbered enemy units. I imagine many of these formations would work well for flying cavalry, with perhaps some tweaking. Sphere, for example, would be better as a defensive formation - protecting the "target" from all sides, rather than surrounding and firing upon an enemy target.
>
> What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
>
>
>
I feel like evasion would be more effective as a defensive measure on flying animals than armor. If ranges are long and speeds high, landing a blow will be hard anyway, and everything you can do to lighten the load on the mount would increase the odds of avoiding incoming fire. Heavy armour would only have real value if the creatures regularly close to melee ranges in order to strike with talons and such.
Regardless of how riders are armoured, the easiest way to take them out of the fight would be to either dismount the rider (so he falls to his death) or to attack the mount and force it to retreat/land. So lances and other long pole-arms would be favoured over swords or axes (as dismounting the rider is easier and more effective than stabbing them until they die in the saddle.)
The mount probably can't fly with too much barding, so bows & arrows could be viable weapons as well - aiming at the mount's wings or face rather than the rider directly. **Flaming arrows** would be doubly effective - not only would the fire damage the mount if it hits, but even a near miss could cause the mount to panic. It might flee the battle regardless of its rider, or make sudden course changes that end up dislodging the rider entirely.
>
> Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
>
>
>
Depends on the range between the city and the battle, of course. I feel like ballistae might be a better fit than catapults in most cases.
If people have access to any kind of explosives, then explosive rounds would obviously be favoured. Fire into a clump of enemy units and aiming becomes much less important (which is important, because aiming at fast-moving flying units over long distances is hard.)
Aside from explosives, flaming ammunition would also be useful, as discussed above. Also, nets. A big net with weights around the edges so it spreads out in flight and has enough inertia to entangle targets and send them plummeting to the ground. Range would be relatively short without some kind of delayed deployment system, but that's up the details of your world, I suppose. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | When designing a weapon we must always keep the 3 main things in mind: **Offensive power, defensive power and mobility**. To strike a good balance between these is hard. See [tanks](https://en.wikipedia.org/wiki/Tank), [airplanes](https://en.wikipedia.org/wiki/Aircraft_design_process) or just the gear a soldier uses. If a soldier has a heavy weapon he (mostly) becomes more lethal. But also slower to move and harder to hide. Not to mention supply problems it might generate.
The Team
--------
I assume the rider and mount function at least at the level of a competent horseman and his mount. That is, they work smoothly as a team and the rider has his hands free to do other stuff then ride. And does not fall off during flying under normal conditions.
While your Giant Flying Creatures will have awesome mobility, their defense will sorely lack. With the rider providing the longer range offensive power and the creature the tooth to claw department. Arrows are likely to bring a big flying thing down. Might need more then one, but still.
---
Group Option:
-------------
The big flying beasts are numerous and so are the people that can ride them.
When your flying opponents will meet between the cities it might look like a cross between [horse archers](https://en.wikipedia.org/wiki/Mounted_archery) and WW1 [aerial tactics](https://en.wikipedia.org/wiki/Air_combat_manoeuvring).
---
Solo, or small group Option:
----------------------------
There are few knights of the sky. The few that fly are or rich or extremely skilled. Rare are the ones that are both. (Depending on government system, of course)
The combat itself can be more like the knights, but with bow and arrow. It might even evolve into a ritualized combated, where no one is killed due to the high cost.
---
But...
------
([Youtube](https://www.youtube.com/watch?v=gumuNn2PAQo) links) When groups of people can prepare and the flying knights have to get close, they are easy prey. Think of nets ([how to train Your Dragon](https://www.youtube.com/watch?v=BzOXF7qklGg)), ballista or other big arrow throwing thing. And worse of all: [archers volly fire](https://www.youtube.com/watch?v=2ADhF_paQOk). They will blood out the sun. And so you will fight in the shade of you falling knights of the wing.
As always you can use you fliers to just [drop stones](https://www.youtube.com/watch?v=VMFbW-3FAK8) on the enemy, out of reach of the archers, naturally. Even [Sabaton](https://www.youtube.com/watch?v=NLo3-e3cZKQ) [sings](https://www.youtube.com/watch?v=cneR4iDG9N0) about it. | Assuming mounted riders with some sort of harness for stability, I would discount any type of hand held melee weapon or even lances - too much chance of a mid-air between mounts and both sides would go down. You need to use some sort of distance weapon. That said, crossbows are too hard to reload, long bows are too ungainly - a mid size bow might be reasonable. Still, with the air currents your mount, other mounts and the enemy mounts are generating, hits are low probability. An entanglement weapon like a bola might work.
Regarding the citidels, assuming you're using the mount as a bomber (dropping incendiary or explosives) then catapults and arbalests might be like the flak gun of WW2. Load the catapult with shot or even hot shot (getting hit with burning hot rocks - not fun) and if you can - some sort of timed explosive with shrapnel. The arbalests would be nicer with explosives or with some sort of deployed net.
Regarding maneuvers - individual maneuvering is usually for air-to-air combat where hitting the other flyer is the main objective. When bombing, you usually have a set formation with the defensive gunnery hopefully overlapping and interlocking and providing for your defense. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | When designing a weapon we must always keep the 3 main things in mind: **Offensive power, defensive power and mobility**. To strike a good balance between these is hard. See [tanks](https://en.wikipedia.org/wiki/Tank), [airplanes](https://en.wikipedia.org/wiki/Aircraft_design_process) or just the gear a soldier uses. If a soldier has a heavy weapon he (mostly) becomes more lethal. But also slower to move and harder to hide. Not to mention supply problems it might generate.
The Team
--------
I assume the rider and mount function at least at the level of a competent horseman and his mount. That is, they work smoothly as a team and the rider has his hands free to do other stuff then ride. And does not fall off during flying under normal conditions.
While your Giant Flying Creatures will have awesome mobility, their defense will sorely lack. With the rider providing the longer range offensive power and the creature the tooth to claw department. Arrows are likely to bring a big flying thing down. Might need more then one, but still.
---
Group Option:
-------------
The big flying beasts are numerous and so are the people that can ride them.
When your flying opponents will meet between the cities it might look like a cross between [horse archers](https://en.wikipedia.org/wiki/Mounted_archery) and WW1 [aerial tactics](https://en.wikipedia.org/wiki/Air_combat_manoeuvring).
---
Solo, or small group Option:
----------------------------
There are few knights of the sky. The few that fly are or rich or extremely skilled. Rare are the ones that are both. (Depending on government system, of course)
The combat itself can be more like the knights, but with bow and arrow. It might even evolve into a ritualized combated, where no one is killed due to the high cost.
---
But...
------
([Youtube](https://www.youtube.com/watch?v=gumuNn2PAQo) links) When groups of people can prepare and the flying knights have to get close, they are easy prey. Think of nets ([how to train Your Dragon](https://www.youtube.com/watch?v=BzOXF7qklGg)), ballista or other big arrow throwing thing. And worse of all: [archers volly fire](https://www.youtube.com/watch?v=2ADhF_paQOk). They will blood out the sun. And so you will fight in the shade of you falling knights of the wing.
As always you can use you fliers to just [drop stones](https://www.youtube.com/watch?v=VMFbW-3FAK8) on the enemy, out of reach of the archers, naturally. Even [Sabaton](https://www.youtube.com/watch?v=NLo3-e3cZKQ) [sings](https://www.youtube.com/watch?v=cneR4iDG9N0) about it. | This has been done (sort of) an old Nintendo Arcade Game called JOUSTE. Check it out - it's my all time favourite arcade game.
Needless to say, I think this new idea you have is fantastic. :) |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | I would imagine the fights to be more like bird combat than like anything humans have ever done.
Consider for a moment that you are seated on top of a large bird in the manner of a horse. First problem is that the bird would need you to sit near the middle of the wing in order to maintain it's front-rear balance. This means the wings/head/tail are in your way for shooting or lances, unless you're aiming up. Also, you have a 30+mph headwind or so, so archery would require an extreme level of skill.
For physical melee, birds usually gain height and dive into their prey for a beak or talon strike to the exposed back. If the goal were just to have humans guide the bird's attacks, then the bird would probably gain height then try to dive from above. I would think that strategy would always be about trying to get the upper positioning on an opponent. There might be coordinated strategies where they try to bait upper enemies into dives, then dodge, leaving the enemy at a lower altitude afterward. If one or two fighters bait the enemy well, it could leave many enemies at a lower altitude so that allies can then attack them from above.
Another thing to consider is weight. The animal with the least extra weight will have the best maneuverability and ability to gain altitude. Since the rider isn't using strength, I think you'd end up in a horse racing situation where the smallest lightest jockeys win the most. It could even be a job for children. But on the topic of gaining altitude, birds do this by circling in thermals (hot air that naturally lifts them upward, saving the very great effort of flapping their wings). So then, thermals will be a strategic feature of the battleground, which both sides would seek to control. Whoever is highest in the thermal would have the best ability to strike those below, and also re-gain altitude afterward if their side maintains control of the thermal.
And finally, you have to consider what their goal is if the enemy air force is defeated. Recon was a good enough reason in WWI, but if you want this to be a long-running technology then they will probably have moved to things like dropping burning pitch on enemy structures or something. I would imagine that smaller lighter "fighters" would guard the more encumbered "bombers" in much the same way that the modern airforce does, simply because an encumbered bird can't do much in an air-fight, and an un-equipped bird can't do much against ground targets.
For a final image of all this, imagine that you have the pilot hanging from straps *under* the bird, able to see where they're going easily and fire a crossbow at lower targets or pull a pin to drop burning pitch, while a child rides on top facing backward with a crossbow to defend the bird from attacks from above/behind. The crossbow would be for last-second counters against an incoming dive, and not for long-range attack. The squadron sends the fastest fliers out first to find the thermals, gain altitude, and defend them as the rest of the fighters reach the thermal, while the "bombers" follow a bit later (once they determine the skies are under control) to make a direct route for enemy targets before they get tired or the pitch cools off. The bombers have to maintain high enough altitude to not get hit by arrows from the ground, but low enough to actually hit their targets.
Update
------
Thinking more on this, the under-pilot and rear-gunner configuration I described might be ok for a "bomber", but if the animals are in fact coming into contact then a lance might still be a useful weapon. Also a single-person configuration would be ideal for the fighter role. But, I still think a saddle/sitting position is unlikely to work. However, if the pilot were to lay flat on the back of the mount, then their weight would be relatively centered while still being able to look over the wing and see below. Also much more aerodynamic this way. There might be a strap-based harness that allows the pilot to flip over onto his back to watch for attacks from above/behind, and then there could be lances mounted to the bird and trailing in the wind which the pilot would grab and aim in the event of an attack. If the attacker didn't abort the dive or dodge, the enemy mount would be impaled while the defending mount would just be knocked downward a few hundred feet as the pilot either frees or discards the lance. This would change dives from a standard attack to more of a surprise/opportunistic attack if they thought the other pilot wasn't going to be able to ready a lance in time. (or if he runs out of lances) Crossbow would probably still be a useful weapon, but now that the pilot is handling multiple weapons and laying down it might need to be tethered to their shoulder or something.
* [Peregrine Falcon dive attack](https://youtu.be/Hpz66RYD110)
* [Mid-air eagle fight](https://youtu.be/tufnqWNP9AA?t=48) | I would think that the problem with catapults is the lack of accuracy, especially with such high moving targets. Might be something to think about. Perhaps a more accurate land to air weapon. Idk, in a fictional universe perhaps you can make the catapults more accurate somehow. With the whole debacle on fighting, I would think if the mounts are capable of aerial dogfight-esque movements, it wouldn't be steady enough for good archery technique. Long weapons might be cool though, like spears and such. A bit like jousting in medieval times. Formation wise, they should move a bit like a flock of birds no? Maybe like hawks. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | More importantly, WHY would they fight? The "why" will tell you the "how."
Armored cavalry (kights) were a terrifyingly effective force. It smashed through most infantry formations, and often caused them to break. Since infantry is what lets you actually conquer an area (I know that's a huge simplification), having something which beats infantry is pretty great.
Flying knights are cool. But what do they **do**?
* They fight like Mongol raiders. They have bows and arrows, and rain down arrows until the opposing force is softened up enough for them to land and engage. Once engaged, they fight a very mobile battle, harrying and retreating so that they always have a local numerical advantage. If the opposing force stays in good enough order to prevent that, they keep shooting from way high in the sky. They are probably lightly armored, and survive by not being reachable. In this case, skycav fights look like archery battles. Mongol-ish may mean crazy athletic sky-horsemanship though, so you might have people leaping from one skyhorse to another.
* They fight like Dragoons. The knights are an infantry force, but are mounted to gain mobility. In a pitched battle, they land in some tactically useful place, and fight there. This fits well with being armored, which would make fighting while cut off from a supporting army much more survivable. This style also lends itself to raids. Duels probably look like both knights landing, then fighting on the ground. That's not unreasonable; You're essentially looking at fights between two airborne groups which look more like naval conflicts without cannons.
* They fight like armored cavalry. They carry lances and charge through infantry, or carry sabers and charge through infantry. This is the least good option, because it means regular knights are *better* than flying knights (if nothing else, trampling is better than not-trampling). Their biggest advantage is probably that they can line up charges from unexpected directions more easily. If they like lances, this looks awesome. If they like swords, they probably can't duel at all (except by landing).
* They fight like spitfires. The mounts are a primary weapon (e.g. fire-breathing dragons). They strafe infantry and kill them from far enough away that infantry can't respond. In this case, they dogfight like spitfires too.
* They fight like engineers (the original, military kind). In this case, they probably drop stuff on infantry from way high up. Maybe they drop stuff on forts too. Fire, rocks, whatever. In this case, they probably duel by trying to drop stuff on each other: everything is careful maneuver, etc.
* They fight like fighter planes. Aircav *generally* have some other role, which is effective enough that you have dedicated anti-air flyers. They probably are very lightly armored, and use nets and bolos (or whatever). Killing the opposing guy doesn't matter, making it so his mount falls out of the sky is easier and more effective. | Assuming mounted riders with some sort of harness for stability, I would discount any type of hand held melee weapon or even lances - too much chance of a mid-air between mounts and both sides would go down. You need to use some sort of distance weapon. That said, crossbows are too hard to reload, long bows are too ungainly - a mid size bow might be reasonable. Still, with the air currents your mount, other mounts and the enemy mounts are generating, hits are low probability. An entanglement weapon like a bola might work.
Regarding the citidels, assuming you're using the mount as a bomber (dropping incendiary or explosives) then catapults and arbalests might be like the flak gun of WW2. Load the catapult with shot or even hot shot (getting hit with burning hot rocks - not fun) and if you can - some sort of timed explosive with shrapnel. The arbalests would be nicer with explosives or with some sort of deployed net.
Regarding maneuvers - individual maneuvering is usually for air-to-air combat where hitting the other flyer is the main objective. When bombing, you usually have a set formation with the defensive gunnery hopefully overlapping and interlocking and providing for your defense. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | I would imagine the fights to be more like bird combat than like anything humans have ever done.
Consider for a moment that you are seated on top of a large bird in the manner of a horse. First problem is that the bird would need you to sit near the middle of the wing in order to maintain it's front-rear balance. This means the wings/head/tail are in your way for shooting or lances, unless you're aiming up. Also, you have a 30+mph headwind or so, so archery would require an extreme level of skill.
For physical melee, birds usually gain height and dive into their prey for a beak or talon strike to the exposed back. If the goal were just to have humans guide the bird's attacks, then the bird would probably gain height then try to dive from above. I would think that strategy would always be about trying to get the upper positioning on an opponent. There might be coordinated strategies where they try to bait upper enemies into dives, then dodge, leaving the enemy at a lower altitude afterward. If one or two fighters bait the enemy well, it could leave many enemies at a lower altitude so that allies can then attack them from above.
Another thing to consider is weight. The animal with the least extra weight will have the best maneuverability and ability to gain altitude. Since the rider isn't using strength, I think you'd end up in a horse racing situation where the smallest lightest jockeys win the most. It could even be a job for children. But on the topic of gaining altitude, birds do this by circling in thermals (hot air that naturally lifts them upward, saving the very great effort of flapping their wings). So then, thermals will be a strategic feature of the battleground, which both sides would seek to control. Whoever is highest in the thermal would have the best ability to strike those below, and also re-gain altitude afterward if their side maintains control of the thermal.
And finally, you have to consider what their goal is if the enemy air force is defeated. Recon was a good enough reason in WWI, but if you want this to be a long-running technology then they will probably have moved to things like dropping burning pitch on enemy structures or something. I would imagine that smaller lighter "fighters" would guard the more encumbered "bombers" in much the same way that the modern airforce does, simply because an encumbered bird can't do much in an air-fight, and an un-equipped bird can't do much against ground targets.
For a final image of all this, imagine that you have the pilot hanging from straps *under* the bird, able to see where they're going easily and fire a crossbow at lower targets or pull a pin to drop burning pitch, while a child rides on top facing backward with a crossbow to defend the bird from attacks from above/behind. The crossbow would be for last-second counters against an incoming dive, and not for long-range attack. The squadron sends the fastest fliers out first to find the thermals, gain altitude, and defend them as the rest of the fighters reach the thermal, while the "bombers" follow a bit later (once they determine the skies are under control) to make a direct route for enemy targets before they get tired or the pitch cools off. The bombers have to maintain high enough altitude to not get hit by arrows from the ground, but low enough to actually hit their targets.
Update
------
Thinking more on this, the under-pilot and rear-gunner configuration I described might be ok for a "bomber", but if the animals are in fact coming into contact then a lance might still be a useful weapon. Also a single-person configuration would be ideal for the fighter role. But, I still think a saddle/sitting position is unlikely to work. However, if the pilot were to lay flat on the back of the mount, then their weight would be relatively centered while still being able to look over the wing and see below. Also much more aerodynamic this way. There might be a strap-based harness that allows the pilot to flip over onto his back to watch for attacks from above/behind, and then there could be lances mounted to the bird and trailing in the wind which the pilot would grab and aim in the event of an attack. If the attacker didn't abort the dive or dodge, the enemy mount would be impaled while the defending mount would just be knocked downward a few hundred feet as the pilot either frees or discards the lance. This would change dives from a standard attack to more of a surprise/opportunistic attack if they thought the other pilot wasn't going to be able to ready a lance in time. (or if he runs out of lances) Crossbow would probably still be a useful weapon, but now that the pilot is handling multiple weapons and laying down it might need to be tethered to their shoulder or something.
* [Peregrine Falcon dive attack](https://youtu.be/Hpz66RYD110)
* [Mid-air eagle fight](https://youtu.be/tufnqWNP9AA?t=48) | More importantly, WHY would they fight? The "why" will tell you the "how."
Armored cavalry (kights) were a terrifyingly effective force. It smashed through most infantry formations, and often caused them to break. Since infantry is what lets you actually conquer an area (I know that's a huge simplification), having something which beats infantry is pretty great.
Flying knights are cool. But what do they **do**?
* They fight like Mongol raiders. They have bows and arrows, and rain down arrows until the opposing force is softened up enough for them to land and engage. Once engaged, they fight a very mobile battle, harrying and retreating so that they always have a local numerical advantage. If the opposing force stays in good enough order to prevent that, they keep shooting from way high in the sky. They are probably lightly armored, and survive by not being reachable. In this case, skycav fights look like archery battles. Mongol-ish may mean crazy athletic sky-horsemanship though, so you might have people leaping from one skyhorse to another.
* They fight like Dragoons. The knights are an infantry force, but are mounted to gain mobility. In a pitched battle, they land in some tactically useful place, and fight there. This fits well with being armored, which would make fighting while cut off from a supporting army much more survivable. This style also lends itself to raids. Duels probably look like both knights landing, then fighting on the ground. That's not unreasonable; You're essentially looking at fights between two airborne groups which look more like naval conflicts without cannons.
* They fight like armored cavalry. They carry lances and charge through infantry, or carry sabers and charge through infantry. This is the least good option, because it means regular knights are *better* than flying knights (if nothing else, trampling is better than not-trampling). Their biggest advantage is probably that they can line up charges from unexpected directions more easily. If they like lances, this looks awesome. If they like swords, they probably can't duel at all (except by landing).
* They fight like spitfires. The mounts are a primary weapon (e.g. fire-breathing dragons). They strafe infantry and kill them from far enough away that infantry can't respond. In this case, they dogfight like spitfires too.
* They fight like engineers (the original, military kind). In this case, they probably drop stuff on infantry from way high up. Maybe they drop stuff on forts too. Fire, rocks, whatever. In this case, they probably duel by trying to drop stuff on each other: everything is careful maneuver, etc.
* They fight like fighter planes. Aircav *generally* have some other role, which is effective enough that you have dedicated anti-air flyers. They probably are very lightly armored, and use nets and bolos (or whatever). Killing the opposing guy doesn't matter, making it so his mount falls out of the sky is easier and more effective. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | When designing a weapon we must always keep the 3 main things in mind: **Offensive power, defensive power and mobility**. To strike a good balance between these is hard. See [tanks](https://en.wikipedia.org/wiki/Tank), [airplanes](https://en.wikipedia.org/wiki/Aircraft_design_process) or just the gear a soldier uses. If a soldier has a heavy weapon he (mostly) becomes more lethal. But also slower to move and harder to hide. Not to mention supply problems it might generate.
The Team
--------
I assume the rider and mount function at least at the level of a competent horseman and his mount. That is, they work smoothly as a team and the rider has his hands free to do other stuff then ride. And does not fall off during flying under normal conditions.
While your Giant Flying Creatures will have awesome mobility, their defense will sorely lack. With the rider providing the longer range offensive power and the creature the tooth to claw department. Arrows are likely to bring a big flying thing down. Might need more then one, but still.
---
Group Option:
-------------
The big flying beasts are numerous and so are the people that can ride them.
When your flying opponents will meet between the cities it might look like a cross between [horse archers](https://en.wikipedia.org/wiki/Mounted_archery) and WW1 [aerial tactics](https://en.wikipedia.org/wiki/Air_combat_manoeuvring).
---
Solo, or small group Option:
----------------------------
There are few knights of the sky. The few that fly are or rich or extremely skilled. Rare are the ones that are both. (Depending on government system, of course)
The combat itself can be more like the knights, but with bow and arrow. It might even evolve into a ritualized combated, where no one is killed due to the high cost.
---
But...
------
([Youtube](https://www.youtube.com/watch?v=gumuNn2PAQo) links) When groups of people can prepare and the flying knights have to get close, they are easy prey. Think of nets ([how to train Your Dragon](https://www.youtube.com/watch?v=BzOXF7qklGg)), ballista or other big arrow throwing thing. And worse of all: [archers volly fire](https://www.youtube.com/watch?v=2ADhF_paQOk). They will blood out the sun. And so you will fight in the shade of you falling knights of the wing.
As always you can use you fliers to just [drop stones](https://www.youtube.com/watch?v=VMFbW-3FAK8) on the enemy, out of reach of the archers, naturally. Even [Sabaton](https://www.youtube.com/watch?v=NLo3-e3cZKQ) [sings](https://www.youtube.com/watch?v=cneR4iDG9N0) about it. | I would think that the problem with catapults is the lack of accuracy, especially with such high moving targets. Might be something to think about. Perhaps a more accurate land to air weapon. Idk, in a fictional universe perhaps you can make the catapults more accurate somehow. With the whole debacle on fighting, I would think if the mounts are capable of aerial dogfight-esque movements, it wouldn't be steady enough for good archery technique. Long weapons might be cool though, like spears and such. A bit like jousting in medieval times. Formation wise, they should move a bit like a flock of birds no? Maybe like hawks. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | >
> Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
>
>
>
This would depend on the maneuverability of the animal as well as how securely the rider is attached to the mount. Giant Eagles could probably do loop-de-loops, but if the rider is just sitting in a saddle equivalent to a horse's saddle, there's a decent chance he might fall out!
(I'm assuming significant G-forces - the likes of which might make a rider black out - wouldn't come into play, because a giant eagle would be moving more slowly than an airplane, but if I'm wrong, I'm sure someone will correct me.)
**Edit:** As Peter mentions in the comments, some real-life birds have been clocked pulling upwards of 10Gs, so the G-Force issue could be a concern for these riders, subject to the abilities of the mount itself.
>
> How would the military formations be?
>
>
>
Whenever I think of fighting formations in 3D, I think of the video game [Homeworld.](http://homeworld.wikia.com/wiki/Formations) You have your standard "wall" and "sphere" formations, an "arrow-head" formation for breaking enemy formations and a "claw" formation for quickly surrounding outnumbered enemy units. I imagine many of these formations would work well for flying cavalry, with perhaps some tweaking. Sphere, for example, would be better as a defensive formation - protecting the "target" from all sides, rather than surrounding and firing upon an enemy target.
>
> What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
>
>
>
I feel like evasion would be more effective as a defensive measure on flying animals than armor. If ranges are long and speeds high, landing a blow will be hard anyway, and everything you can do to lighten the load on the mount would increase the odds of avoiding incoming fire. Heavy armour would only have real value if the creatures regularly close to melee ranges in order to strike with talons and such.
Regardless of how riders are armoured, the easiest way to take them out of the fight would be to either dismount the rider (so he falls to his death) or to attack the mount and force it to retreat/land. So lances and other long pole-arms would be favoured over swords or axes (as dismounting the rider is easier and more effective than stabbing them until they die in the saddle.)
The mount probably can't fly with too much barding, so bows & arrows could be viable weapons as well - aiming at the mount's wings or face rather than the rider directly. **Flaming arrows** would be doubly effective - not only would the fire damage the mount if it hits, but even a near miss could cause the mount to panic. It might flee the battle regardless of its rider, or make sudden course changes that end up dislodging the rider entirely.
>
> Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
>
>
>
Depends on the range between the city and the battle, of course. I feel like ballistae might be a better fit than catapults in most cases.
If people have access to any kind of explosives, then explosive rounds would obviously be favoured. Fire into a clump of enemy units and aiming becomes much less important (which is important, because aiming at fast-moving flying units over long distances is hard.)
Aside from explosives, flaming ammunition would also be useful, as discussed above. Also, nets. A big net with weights around the edges so it spreads out in flight and has enough inertia to entangle targets and send them plummeting to the ground. Range would be relatively short without some kind of delayed deployment system, but that's up the details of your world, I suppose. | I would think that the problem with catapults is the lack of accuracy, especially with such high moving targets. Might be something to think about. Perhaps a more accurate land to air weapon. Idk, in a fictional universe perhaps you can make the catapults more accurate somehow. With the whole debacle on fighting, I would think if the mounts are capable of aerial dogfight-esque movements, it wouldn't be steady enough for good archery technique. Long weapons might be cool though, like spears and such. A bit like jousting in medieval times. Formation wise, they should move a bit like a flock of birds no? Maybe like hawks. |
79,065 | In my world, we have two cities, each on a high mountaintop, separated by a vast valley. In order to wage war, the warriors of each city bridge the huge gap between them by using flying creatures.
Now, these flying creatures are of various natures... Some are dragon-like pterodactyls, others are giant eagles. But each one can carry only one warrior and his gear. The warriors saddle and mount the beasts like they would do with horses.
Their technology is on the medieval level. Warriors can only use swords, spears, bows and arrows and such. The cities may, however, be furnished with catapults.
Since these battles never existed in real life, I'm a little overwhelmed at how these battles would be. On the one hand, I'm inclined to base myself on real medieval calvary battles, since we're dealing with knights riding living creatures. On the other hand, the specifics of these creatures make me feel tempted to base myself on real aerial WW2 battles to know how they would move in battle and keep formations.
So, my questions would be as such:
1. Could these warriors make the same kinds of acrobatic flights that airplanes did on real aerial battles?
2. How would the military formations be?
3. What would be the best tactics for warriors to fight each other? Would long range fighting bow and arrows be sufficiently precise? Would short range joust-like figthing be feasible?
4. Would the catapults from the cities be able to disrupt the battle, or inflict any damage, knowing that the warriors could dodge on all three axes?
---
**Edit**: not a duplicate from [How to make a viable flying mount?](https://worldbuilding.stackexchange.com/questions/69163/how-to-make-a-viable-flying-mount), since I'm not interested in the anatomy of the creatures, but in battle details.
---
**Edit 2**: I'm not interested in the creatures' feasibility. Their anatomy would be the anatomy of a giant eagle and pterodactyls with a size able to sustain a warrior. The physics are similar to our world's.
I would like the answers not to focus on the creatures themselves, but rather on how the warriors would fight with them and on them.
---
**Edit 3**
Since the question was put [on hold] for being too broad, I have split this question into three separate ones. Below are the links:
1. [Aerial battle of knights riding flying creatures - preferred weapons for the warriors](https://worldbuilding.stackexchange.com/questions/79255/aerial-battle-of-knights-riding-flying-creatures-preferred-weapons-for-the-war)
2. [Aerial battle of knights riding flying creatures - how would their military formations be?](https://worldbuilding.stackexchange.com/questions/79346/aerial-battle-of-knights-riding-flying-creatures-how-would-their-military-form)
3. [How can a city protect itself from the invasion from knights flying riding creatures?](https://worldbuilding.stackexchange.com/questions/79481/how-can-a-city-protect-itself-from-the-invasion-from-knights-flying-riding-creat) | 2017/04/24 | [
"https://worldbuilding.stackexchange.com/questions/79065",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/20681/"
] | I will base my answer according the the following details:
* The Knights are harnessed onto these animals in such a way that they can ride with their hands free
* The animals are capable of sufficient thrust to not "stall out" during a near-vertical climb (at least for a short distance)
* There are at least two "classes" of flying creature: 1 that can carry heavier burdens but is comparably slower, and one that can only carry light burdens with greater agility
In aerial combat with a floor and a sky, you're dealing with one major physical consideration: gravity. The nature of gravity makes it clear that going up requires power and loses speed, and going down returns speed and requires no power. As your height increases so to do your options; conversely, as your height decreases so to do your options. Take this in mind with the answers below.
1. In short - No. These warriors would be limited by the power output of the mount. They could climb for short distances, certainly, but not nearly at the same speed as planes in almost any era. However, the creatures will have one clear strength: the ability to manipulate their control surfaces (wings). A plan does not have the ability to makes its wings effectively disappear, but a flying creature can pull its wings in, offering interesting possibilities for maneuvers and aerobatics that a plane does not have.
2. Formation in the context of aerial maneuver is less about form and more about protection. In any given air combat scenario, an attacker is somewhat limited because he must be moving forward at all times, which is to say that he can only focus on one target at any given time. In practice, this transforms into the notion that a formation is about keeping a group together that can at least match - and hopefully exceed - an enemy group's numbers, and also allow every pilot to have a wingman, which generally means using even numbers. Aside from that, your formation can either reveal or conceal your numbers, and either limit or increase individuals visibility. This lends to the standard V-formation as being a balanced deployment: Your group as the lowest possible silhouette and the great possible sight-lines while still being close enough to one another to provide support.
3. In air combat, the usual standby concept is: Get on your enemy's tail while keeping yours safe. In this context, I can see that still being relevant, with some modifications. First off, if a mount is damaged, the rider can be as safe as he wants, he will fall and likely die. Therefore, first-target should probably be the mount. It's large silhouette compared to the rider makes it a more ideal target as well. Any disabling weapon would be useful here: bolas, weighted-nets, etc. would allow a flier to render a combatant flightless with relative ease. Long-range weapons would be ideal. At flying speeds, the weapon must have sufficient speed to be effective. A powerful cross-bow would be ideal, especially since the rider could still be evasive while reloading. Close range weapons should be of last resort, as in the case where a rider is close enough to use such a weapon, even a standard pole arm, it is as likely some complication in combat could kill both mounts and render both fliers downed.
4. Catapults could be useful, but only if fired in large groups according to the enemies anticipated trajectory. One boulder would be ineffective, but tens of them raining on the approaching fliers would at least limit their mobility options. If timed correctly, such a tactic could render entire portions of an approaching group defeated outright, allowing the defenders a more advantageous position.
There is a reason that the most effective defenses against bombers for many years were flak cannons. Rounds that detonate into deadly shards make short work of planes, as would also be the case with fleshy mounts. Any dabbling with explosives, no matter how minor, would give one of the two armies a massive advantage in both defensive and offensive power. | Considering flying battles, I would suggest inspiration from the WW1 dogfights rather than medieval style fighting. It also depends to a large deal on the kind of armour your warriors prefer to use. Using anything but greatswords or gigantic battle axes against full plate armour might be almost useless.
Personally, I feel rather than having actual weapons to the fight, the flying animals themselves can be used as weapons. The creatures will certainly have talons and beaks that can be used to attack each other, with the warrior actually guiding the animal to do the dirty work.
If you want weapons, something like giant lances can do the trick by simply dismounting their opponents so that they fall to their deaths.(similar to jousting in medieval Europe, just the distance of the fall is greater)
If mail armour is being worn, might I suggest a handheld Chinese Repeating Crossbow. It could fire arrow bolts at a staggering rate, almost like a medieval machine gun. In case of plate armour, you can make it a larger Repeating Crossbow fixed onto the creature, allowing for the use of larger arrows or even small spears that might pierce the armour.As for the arrows, they can be carried as a line of arrows on a stripper clip (Similar to the ones used in WW1 rifles like Gwehr)
Hope this helped. :) |
18,806 | I had ran ethereum for some time for developing. I had upgrade to the latest Mist 0.8.10, Wallet 0.8.10 and geth 1.6.5 on Windows 10. after this, everything seems to break, everytime i start my mist it will shows "node connection error".
After i deleted everything from User\Appdata - mist, wallet, geth and reinstall mist again (without separately installing geth). it is working ok until i switch from main to testnet. the same problem occured.
anyone have experience to resolved this issue and switch from main to testnet seamlessly?
i have no problem running geth from command line before launching mist or wallet. It will sync all the blockchain when mist starts.
[](https://i.stack.imgur.com/wsqY5.png) | 2017/06/26 | [
"https://ethereum.stackexchange.com/questions/18806",
"https://ethereum.stackexchange.com",
"https://ethereum.stackexchange.com/users/11828/"
] | Run mist.exe as administrator. | Are you sure that geth is running? The "node" that mist can't connect to is (I assume) a geth node on your computer. If geth isn't running, then mist can't "connect to node" and you would get an error. |
18,806 | I had ran ethereum for some time for developing. I had upgrade to the latest Mist 0.8.10, Wallet 0.8.10 and geth 1.6.5 on Windows 10. after this, everything seems to break, everytime i start my mist it will shows "node connection error".
After i deleted everything from User\Appdata - mist, wallet, geth and reinstall mist again (without separately installing geth). it is working ok until i switch from main to testnet. the same problem occured.
anyone have experience to resolved this issue and switch from main to testnet seamlessly?
i have no problem running geth from command line before launching mist or wallet. It will sync all the blockchain when mist starts.
[](https://i.stack.imgur.com/wsqY5.png) | 2017/06/26 | [
"https://ethereum.stackexchange.com/questions/18806",
"https://ethereum.stackexchange.com",
"https://ethereum.stackexchange.com/users/11828/"
] | Run mist.exe as administrator. | I had deleted the mist browser again and used the zipped version instead of installer version. The problem goes away.. |
18,806 | I had ran ethereum for some time for developing. I had upgrade to the latest Mist 0.8.10, Wallet 0.8.10 and geth 1.6.5 on Windows 10. after this, everything seems to break, everytime i start my mist it will shows "node connection error".
After i deleted everything from User\Appdata - mist, wallet, geth and reinstall mist again (without separately installing geth). it is working ok until i switch from main to testnet. the same problem occured.
anyone have experience to resolved this issue and switch from main to testnet seamlessly?
i have no problem running geth from command line before launching mist or wallet. It will sync all the blockchain when mist starts.
[](https://i.stack.imgur.com/wsqY5.png) | 2017/06/26 | [
"https://ethereum.stackexchange.com/questions/18806",
"https://ethereum.stackexchange.com",
"https://ethereum.stackexchange.com/users/11828/"
] | Run mist.exe as administrator. | My sollution was to use "Ethereum wallet" (zip version) instead of "Mist".
(No one sollution described above worked for me) |
14,979,311 | I'm trying to use linkedin javascript api, but when I run a script I get an error 'javascript api domain is restricted to localhost'. Does anyone know what is that? Please, help! | 2013/02/20 | [
"https://Stackoverflow.com/questions/14979311",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/2091018/"
] | 1. Go to <https://www.linkedin.com/secure/developer>
2. Click on the application name you're using.
3. Add your domain to *JavaScript API Domains:*
4. Save changes.
This should fix your issue. | 1 create a new app on LinkedIn devloper
2.in URL you should write path like this
<http://localhost/linkdin/index.php/>
then save
after it your problem will be resolve |
5,223 | I've got the Battlestar Galactica board game and I absolutely love it. I'm thinking of getting one of the expansions for it but I'm torn between the *Exodus* and *Pegasus* expansions.
How do these expansions change the game? and from people who have played both which do you think is a better expansion?
Note that since this question was written the *Daybreak* expansion has been added too. | 2011/11/01 | [
"https://boardgames.stackexchange.com/questions/5223",
"https://boardgames.stackexchange.com",
"https://boardgames.stackexchange.com/users/1965/"
] | The rules for both variants are available at FFG's site, so you can read them for the full details. Both expansions contain an "alternate ending" which can replace the Kobol objective, kicking in when the fleet jumps to distance 7. Both have new character and skill cards. Both expansions include the possibility that characters will be *executed*, not just brigged - it's a bigger feature in Pegasus.
Summary first, then discussion:
Pegasus
-------
In general, this expansion adds a lot of "tweaks" to the gameplay; once you've got it, you'll probably use most of the new rules every game.
* **New characters:** Admiral Cain, Ellen Tigh, Kat, Dee.
* **New cards:** Lots of new and interesting crises, and most of the new skill cards are in this set. There are an additional 1,2,3,4, and 5 card for each skill deck, with some useful new powers. Compensating for this is the new "Treachery" skill, which only goes from 1-3 but is always negative, and has special text only usable by cylons. Unfortunately it's not safe to discard either, as some booby-trap Treachery cards can hurt the humans if you do... *Anyone* drawing treachery is good news for the cylons. (And some new crises can force you to draw treachery.)
* **Major new rule: Pegasus.** The humans get an extra battlestar board with four new locations. This gives the humans more effective guns against raider swarms, and another way to hurry up jumps. It also adds the lethal "airlock" location - don't want to try to brig that suspect? Just kill them! Of course, a good cylon player can con people into executing other humans...
(This variant makes "destroy Galactica due to damage" cylon win nearly impossible, because the humans can soak 4 extra hits on Pegasus if need be.)
* **Minor variant: Cylon Leaders:** Cavil, Leoben, Caprica Six. These are playable characters, replacing one cylon loyalty card. Effectively, they work like revealed cylons from the start, but can "infiltrate" and rejoin Galactica, playing cards as human crew. They draw an "agenda" describing which team they have to support to win, but it also has a limitation - they mustn't win by too much.
(The idea was to replace the uncertainty of "I don't know who's a cylon" with "I don't know which side the cylon is on". In practice implementation isn't perfect, and this variant reduces the uncertainty.)
* **Variant ending: New Caprica.** Instead of ending after a jump from distance 8, at distance 7 the fleet lands on a "New Caprica" board and is occupied. They then have to take actions to release the civilian ships from lockup while waiting for Galactica to jump back, then defend them while evacuating. Crises are drawn from a new deck of 'during the occupation' crises.
(This definitely favours the cylons, as it's harder than just making one extra fleet jump. If the change from 8 to 7 even saved you one. However, it's hardest if fleet attacks have been light, because there's more civilian ships left to protect, so it evens out a bit.)
Exodus
------
Fewer tweaks to the game, but several major new variants.
* **New characters:** Sam Anders, Tory, Gaeta, Cally.
* **New skill cards:** Some 0 cards for each deck, which have some other effect on the skill check when played. (e.g. the 0 Tactics causes two extra Destiny cards to be played in.) One 6 card for each deck, with special text so good you want to play it for that instead of the 6. (For example, Engineering 6 can be used to build a new nuke.)
* **New crisis cards:** A lot of interesting crises that play off the new rules. There are no new fleet attacks, so if you *don't* play the Cylon Fleet variant, you'll be sharply reducing the proportion of fleet attacks in the deck if you use them.
* **Major variant: Cylon Fleet.** There are no fleet attacks. Instead, cylons build up forces on their own fleet board with it's own jump track. When the cylons jump, they arrive en masse on the main board. When the fleet jumps, surviving cylons move back to their board to build up for next time, but civilian ships are *not* removed. They can be escorted off by vipers instead, but that uses up precious actions. Humans get an extra title, CAG, which helps command unmanned fighters, as well as some better Vipers.
(This evens out the randomness of fleet attacks, but with competent cylons can make the buildup of raiders harder to deal with in the endgame... by the end most of the civilian fleet could be on the board. Works better when used in conjunction with the Pegasus; otherwise the humans can be a touch outgunned. You will *need* your nukes.)
* **Variant ending: Ionian Nebula.** This changes the game by making much more use of the cast of characters. As well as the characters in play, you have random extra characters all over the ship, and a limited supply of "Trauma" tokens used to decide whether they do good or bad things when encountered. At distance 7 you enter the Nebula and there's an extra round of personal crises (an extra random dilemma to face) and possibly executions, depending on how well you've done at getting rid of your 'bad' counters.
(So this variant emphasizes character interaction more, and gives you a whole new set of possible suspicious behaviours to indulge in. Properly managed by humans it *can* result in a lot of extra fleet bonuses... but needn't.)
* **Minor variants: Conflicted Loyalties / Final Five.** Characters have additional personal goals that they have to accomplish to win. Final Five Cylons, if used, also go in the "Not a Cylon" loyalty slots - they count as being on the human side and work like humans, but they make it much less safe to use 'peek at loyalty card' abilities.
(This variant makes life *much* harder for the humans, as they're wasting resources and suspicion dealing with extra side issues.)
Decision Notes
--------------
There's plenty to like in both sets. Which is "better" depends a bit on what you like most about Galactica, and especially on what you like *least*.
* If you like the treachery/uncertainty, but play 4 or 6 player and think the weak "Cylon sympathiser" mechanic is a major flaw, get Pegasus.
* If you dislike the random distribution of fleet attacks, and want to avoid games where there are very few or very many, get Exodus.
* If you think the series cast should appear more, get Exodus.
* If you don't play often, you'll get more out of Pegasus, as Exodus has fewer 'every game' rules changes and more major variants. | I have played both, and each one adds a lot to te game. The first thing they each add is time. they also each add new characters and new a new end game condition.
My favorite version of BSG is playing with both expansions using the end game condition of Exodus.
The Pegasus Expansion adds a second Battlestar ship with 4 extra rooms. These tend to give great power to the human players. They also act as extra damage tokens. My favorite aspect of Pegasus is the treachery cards, which are brown cards that are beneficial for cylons hidden and revealed. The end game of this expansion is New Caprica, which is a separate board and gives a chance for the Cylons to destroy civilian ships before the game ends.
Exodus adds a few more complex additions: cylong fleet board, allies, trauma tokens, and a big battle as an ending.
The main complaint of exodus people give is a player-elimination mechanic. I do not mind this, however, since it is a turn or two before the end.
The Cylon Fleet board is the reason I love playing with Exodus. This edition makes it important to have pilots. The fleet board keeps a steady stream of attackers coming instead of using the fleet setup cards in the crisis deck.
The expansion also allows you to remove civilian ships if you're a pilot, however this is the only way to get them off the board now. Jumping no longer doess. |
74,876 | We have designed multiple temperature sensors. its executed as well too. but we need external power supply or Uninterrupted Power supply for Rpi. I have chosen power bank ..but it works with only one way..which means while charging it doesn't provide output. so please suggest me a proper UPS. | 2017/11/07 | [
"https://raspberrypi.stackexchange.com/questions/74876",
"https://raspberrypi.stackexchange.com",
"https://raspberrypi.stackexchange.com/users/32377/"
] | Here's a couple of USB devices that operates in a UPS fashion.
[Solex Travel powerbank](https://www.amazon.co.uk/Solex-Countries-Simultaneous-Charging-Warranty-Orange/dp/B0742GJ23V)
Or...
[Inepo ups powerbank](https://www.amazon.co.uk/GM312-Uninterrupted-11-13Vdc-Wireless-Peripherals/dp/B06XSZVJ6Q/ref=sr_1_1?ie=UTF8&qid=1510069306&sr=8-1&keywords=powerbank%20ups)
These are just examples for the power bank route, i haven't personally tested the above, but that's the kinda thing you want.
Or if you want to go hardcore, get an entry level server one like this ...
[APC UPS](https://www.ebuyer.com/703990-apc-back-ups-300-watts-500-va-3-x-c13-input-bx500ci)
Which i have personally used for servers and they are handy well built things, heavy as hell though. Do the math against your power draw but one of those could last days running a pi. | If you want to build one you can use a 12V battery feeding a Buck Converter through a 10A diode. then you connect a 15V power supply again feeding the Buck Converter through a 10A diode. Put a float charger on the battery and you are set. You can pick what ever voltages you are comfortable with. You can use a SEPIC converter if like that will cover you when the battery is low. However if the battery is over discharged you will destroy it. If you do not want to build it a simple UPS supplying line voltage will work. They cost a little more then the pi.To size it use the max wattage of the power supply X 1.25 or larger. |
20,681,962 | Recently I asked a question [here](https://stackoverflow.com/questions/20681319/how-to-align-divs-horizontally-which-represents-a-table-row) and one of the answer suggests to use display: table and display: table-cell css properties.
Generally UI designers recommend not to use tables for layout. What if I use these two css properties extesively while layout? Is it the same as using tables for layout? | 2013/12/19 | [
"https://Stackoverflow.com/questions/20681962",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/1912429/"
] | No. HTML tables indicate that their contents are tabular data. This information is exposed to the Accessibility API and so accessibility tools like screen readers can tell their users what to expect in the information following. Note that cell headers may be read out multiple times so that the AT user can orientate themselves while following the data.
CSS tables do not behave like that. They are just layout instructions. The information about the data that the AT user gets will reflect the semantics of the HTML, not the CSS layout. | The display table let the element behave like a element without using a HTML table element, so probably you will have more flexibility on your development. So you will have the benefits of a table and the flexibility of development without table, becase tables are always difficult and and hard to work |
399,669 | I am wondering if there is a way to use the keyboard to move the current app (or at least the current window) to a new space in Lion. Currently the only method I know of is to go to Mission Control and drag the app to the new space. | 2012/03/12 | [
"https://superuser.com/questions/399669",
"https://superuser.com",
"https://superuser.com/users/122533/"
] | The only applications I've found that support it are [SizeUp](http://irradiatedsoftware.com/sizeup/) and [Spacey](http://most-advantageous.com/spacey/). I couldn't get Spacey to work on 10.8, but SizeUp still works for me.
 | <http://www.hongkiat.com/blog/osx-lion-features-shortcuts/>
click within 'Shortcut to:' on OS X lion shortcuts
see 'Move between spaces on desktop (ctrl -> or ctrl <-) |
399,669 | I am wondering if there is a way to use the keyboard to move the current app (or at least the current window) to a new space in Lion. Currently the only method I know of is to go to Mission Control and drag the app to the new space. | 2012/03/12 | [
"https://superuser.com/questions/399669",
"https://superuser.com",
"https://superuser.com/users/122533/"
] | I know this question is a bit old at this point, but it still comes up in Google search results right up at the top.
Better Touch Tool:
<http://www.boastr.net/>
It lets you move windows to different monitors, desktops, resize, etc. all with custom gestures or keyboard shortcuts. It's robust, supports the Apple trackpad, magic mouse, keyboard, regular mouse, Leap motion device and more. | <http://www.hongkiat.com/blog/osx-lion-features-shortcuts/>
click within 'Shortcut to:' on OS X lion shortcuts
see 'Move between spaces on desktop (ctrl -> or ctrl <-) |
399,669 | I am wondering if there is a way to use the keyboard to move the current app (or at least the current window) to a new space in Lion. Currently the only method I know of is to go to Mission Control and drag the app to the new space. | 2012/03/12 | [
"https://superuser.com/questions/399669",
"https://superuser.com",
"https://superuser.com/users/122533/"
] | The only applications I've found that support it are [SizeUp](http://irradiatedsoftware.com/sizeup/) and [Spacey](http://most-advantageous.com/spacey/). I couldn't get Spacey to work on 10.8, but SizeUp still works for me.
 | I know this question is a bit old at this point, but it still comes up in Google search results right up at the top.
Better Touch Tool:
<http://www.boastr.net/>
It lets you move windows to different monitors, desktops, resize, etc. all with custom gestures or keyboard shortcuts. It's robust, supports the Apple trackpad, magic mouse, keyboard, regular mouse, Leap motion device and more. |
114,468 | I want to make a ribbon / wave of dots in Illustrator like the image below, but keep the perspective of the dots, so they don't look flat.
I have not had any luck using the blend tool or envelope distort tools. The dots always get distorted or look flat.
[](https://i.stack.imgur.com/6Yn3K.png) | 2018/08/31 | [
"https://graphicdesign.stackexchange.com/questions/114468",
"https://graphicdesign.stackexchange.com",
"https://graphicdesign.stackexchange.com/users/126564/"
] | Blending distorted circles:
* From two circles located at the ends of the future blend, make three or four distortions following the perspective. More shapes = softer transition.
[](https://i.stack.imgur.com/RDkri.png)
* Use the **Blend Tool** to blend each shape [](https://i.stack.imgur.com/jzMPZ.png)
[](https://i.stack.imgur.com/y56pL.png)
* Draw a spine path
[](https://i.stack.imgur.com/XzmfA.png)
* Select the *Blend* and the *Path* and go to **Menu Object** > **Blend** > **Replace Spine**
[](https://i.stack.imgur.com/xuqLR.png)
* Use the **Group Selection Tool** to select each shape and rotate or scale following the spine
* Duplicate the blend and replace the spine with different paths
[](https://i.stack.imgur.com/xJHM8.png) | Blending can be used to make a straight ribbon. One can create the length and the width by applying 2 blendings. But trying to make a curved one by creating the width with another blending unfortunately creates something which is very difficult to predict exactly. At least the final perspective should be seen in the beginning when creating the length.
Here's another way (Illustrator only) where the perspective can be adjusted at the end and the dots get some streching and squeezing as you adjust.
[](https://i.stack.imgur.com/DGjSg.jpg)
In image 1 there's some dots. The idea is to make the distant dots smaller and to have more grey color to reduce their contrast. In image 1 the dots are zoomed to bigger size to show them properly here.
2. Two straight dot lines are generated with blending, the blend is expanded.
3. another blend generates a straight ribbon
4. The straight ribbon has been bended with Envelope distortion mesh. The mesh has only 1 row and 2 columns to keep it easily controllable.
One can think "of course in 3D it will be better". Questioner's original example has finely fading contrast and dot size. The ribbon has a slight curvature sideways. In simple 3D programs making them is difficult. Leaving them out destroys the effect, it's like an engineering drawing. An example:
[](https://i.stack.imgur.com/L4ui8.jpg)
Good result in 3D is possible if the texture is prepared with blendings in 2D and placed on rich enough 3D surface. That is discussed already in another answer. |
114,468 | I want to make a ribbon / wave of dots in Illustrator like the image below, but keep the perspective of the dots, so they don't look flat.
I have not had any luck using the blend tool or envelope distort tools. The dots always get distorted or look flat.
[](https://i.stack.imgur.com/6Yn3K.png) | 2018/08/31 | [
"https://graphicdesign.stackexchange.com/questions/114468",
"https://graphicdesign.stackexchange.com",
"https://graphicdesign.stackexchange.com/users/126564/"
] | Blending distorted circles:
* From two circles located at the ends of the future blend, make three or four distortions following the perspective. More shapes = softer transition.
[](https://i.stack.imgur.com/RDkri.png)
* Use the **Blend Tool** to blend each shape [](https://i.stack.imgur.com/jzMPZ.png)
[](https://i.stack.imgur.com/y56pL.png)
* Draw a spine path
[](https://i.stack.imgur.com/XzmfA.png)
* Select the *Blend* and the *Path* and go to **Menu Object** > **Blend** > **Replace Spine**
[](https://i.stack.imgur.com/xuqLR.png)
* Use the **Group Selection Tool** to select each shape and rotate or scale following the spine
* Duplicate the blend and replace the spine with different paths
[](https://i.stack.imgur.com/xJHM8.png) | I made some tests using Illustrator and Blender.
Here are the results:
First I made the dots in Illustrator and saved for web in png transparent.
Imported in Blender using Import Images as Planes Addon.
I made the modifications needed.
See the step by step in the image below:
[](https://i.stack.imgur.com/3nFs0.png) |
199,566 | In the *Player's Handbook* there's a list of about 20 "Artisan's Tools" that player characters might have proficiency with, and what those tool kits contain and can do is expanded on in *Xanathar's Guide to Everything*. Two of those kits are Carpenter's tools and Woodcarver's tools, and *Xanathar's* breaks them down the way you'd expect from the names: Carpenter's tools are useful for constructing wooden structures and furniture, while Woodcarver's tools are for detailed carving work like figurines (and arrows). There's a clear distinction here between construction tools and artistic tools.
But there seems to be no such distinction for stone. Mason's tools are obviously the right tool for building brick or stone structures, but seem completely inadequate for doing sculpture work, and there's no "Stonecarver's tools" or "Sculptor's tools" listed.
One of my players has decided to work on a stone carving (for reasons) and I'm suddenly finding myself stymied on what tool kit makes sense for that kind of work. "Mason's tools" seem like the wrong choice for the same reason you wouldn't use carpentry tools to whittle (chainsaw sculpture aside, where part of the art form is that you're using the wrong kind of tools), but I just don't see what else to apply. Surely it wouldn't be woodcarving tools, which are explicitly for use with *wood*. The only kit that sounds even remotely like the artistic version of stonework is the Jeweler's tools, but again, that's a very specific discipline that's not related to carving works of art out of marble.
What's the "right" toolkit to roll for determining how well a statue comes out? | 2022/06/29 | [
"https://rpg.stackexchange.com/questions/199566",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/28298/"
] | ### Just make one up.
This is an area where the risk of unbalancing something with homebrew is nonexistent. Homebrewing magic items and class features have numerous issues that can come up with respect to balance. Homebrewing a tool so a player can have the desired theming for their character carries no such risk. If you think none of the published toolkits are appropriate, just give the character "sculptor's tools" or whatever you think they need to make statues. The tools obviously exist in a world that already has statues, so you aren't actually adding anything new to the universe. | I see 4 options:
----------------
In order of how I would choose them.
**Option 1**
Pick the listed kit that sounds the closest and say 'that one'. It really doesn't matter what you pick as long as you can justify it and let your players know.
**Option 2**
Homebrew a kit that does what you want. If I did this I would probably let a player retcon a proficiency they have already picked if this was their intention all along.
**Option 3**
Why does it need a tool proficiency? Sculpture is art, so get them to make a performance check. Maybe a Dexterity (Performance) check rather than Charisma.
**Option 4 (not a good options, but added for completeness)**
All sculptures are magically created. There is no such mundane ability so your player is out of luck. |
199,566 | In the *Player's Handbook* there's a list of about 20 "Artisan's Tools" that player characters might have proficiency with, and what those tool kits contain and can do is expanded on in *Xanathar's Guide to Everything*. Two of those kits are Carpenter's tools and Woodcarver's tools, and *Xanathar's* breaks them down the way you'd expect from the names: Carpenter's tools are useful for constructing wooden structures and furniture, while Woodcarver's tools are for detailed carving work like figurines (and arrows). There's a clear distinction here between construction tools and artistic tools.
But there seems to be no such distinction for stone. Mason's tools are obviously the right tool for building brick or stone structures, but seem completely inadequate for doing sculpture work, and there's no "Stonecarver's tools" or "Sculptor's tools" listed.
One of my players has decided to work on a stone carving (for reasons) and I'm suddenly finding myself stymied on what tool kit makes sense for that kind of work. "Mason's tools" seem like the wrong choice for the same reason you wouldn't use carpentry tools to whittle (chainsaw sculpture aside, where part of the art form is that you're using the wrong kind of tools), but I just don't see what else to apply. Surely it wouldn't be woodcarving tools, which are explicitly for use with *wood*. The only kit that sounds even remotely like the artistic version of stonework is the Jeweler's tools, but again, that's a very specific discipline that's not related to carving works of art out of marble.
What's the "right" toolkit to roll for determining how well a statue comes out? | 2022/06/29 | [
"https://rpg.stackexchange.com/questions/199566",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/28298/"
] | Masons tools
------------
pre-modern masonry involves a lot more stone carving and sculpting than you think it does.
these are made by masons.
[](https://i.stack.imgur.com/OH34b.png)
[](https://i.stack.imgur.com/fJmcE.png)
[](https://i.stack.imgur.com/MxlrD.jpg)
will there be slight variations in tools, sure but you can say the same for any artisans tools, a siege engineers carpenters tools will be different than a cabinet makers set. X tools is just a general guideline, just like a swordsmith, armorsmith, redsmith, and blacksmith all use "smiths's tools" | ### Just make one up.
This is an area where the risk of unbalancing something with homebrew is nonexistent. Homebrewing magic items and class features have numerous issues that can come up with respect to balance. Homebrewing a tool so a player can have the desired theming for their character carries no such risk. If you think none of the published toolkits are appropriate, just give the character "sculptor's tools" or whatever you think they need to make statues. The tools obviously exist in a world that already has statues, so you aren't actually adding anything new to the universe. |
199,566 | In the *Player's Handbook* there's a list of about 20 "Artisan's Tools" that player characters might have proficiency with, and what those tool kits contain and can do is expanded on in *Xanathar's Guide to Everything*. Two of those kits are Carpenter's tools and Woodcarver's tools, and *Xanathar's* breaks them down the way you'd expect from the names: Carpenter's tools are useful for constructing wooden structures and furniture, while Woodcarver's tools are for detailed carving work like figurines (and arrows). There's a clear distinction here between construction tools and artistic tools.
But there seems to be no such distinction for stone. Mason's tools are obviously the right tool for building brick or stone structures, but seem completely inadequate for doing sculpture work, and there's no "Stonecarver's tools" or "Sculptor's tools" listed.
One of my players has decided to work on a stone carving (for reasons) and I'm suddenly finding myself stymied on what tool kit makes sense for that kind of work. "Mason's tools" seem like the wrong choice for the same reason you wouldn't use carpentry tools to whittle (chainsaw sculpture aside, where part of the art form is that you're using the wrong kind of tools), but I just don't see what else to apply. Surely it wouldn't be woodcarving tools, which are explicitly for use with *wood*. The only kit that sounds even remotely like the artistic version of stonework is the Jeweler's tools, but again, that's a very specific discipline that's not related to carving works of art out of marble.
What's the "right" toolkit to roll for determining how well a statue comes out? | 2022/06/29 | [
"https://rpg.stackexchange.com/questions/199566",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/28298/"
] | Masons tools
------------
pre-modern masonry involves a lot more stone carving and sculpting than you think it does.
these are made by masons.
[](https://i.stack.imgur.com/OH34b.png)
[](https://i.stack.imgur.com/fJmcE.png)
[](https://i.stack.imgur.com/MxlrD.jpg)
will there be slight variations in tools, sure but you can say the same for any artisans tools, a siege engineers carpenters tools will be different than a cabinet makers set. X tools is just a general guideline, just like a swordsmith, armorsmith, redsmith, and blacksmith all use "smiths's tools" | I see 4 options:
----------------
In order of how I would choose them.
**Option 1**
Pick the listed kit that sounds the closest and say 'that one'. It really doesn't matter what you pick as long as you can justify it and let your players know.
**Option 2**
Homebrew a kit that does what you want. If I did this I would probably let a player retcon a proficiency they have already picked if this was their intention all along.
**Option 3**
Why does it need a tool proficiency? Sculpture is art, so get them to make a performance check. Maybe a Dexterity (Performance) check rather than Charisma.
**Option 4 (not a good options, but added for completeness)**
All sculptures are magically created. There is no such mundane ability so your player is out of luck. |
111,197 | QGIS looks straight forward except for the symbols or icons.
I have created SVG symbols and when I place my pointer to the obvious blank areas in the symbol library a pop-up says that my symbol is there, yet nothing shows in the icon library.
I insert the "ghost" svg into the map and Nothing shows on the map.
Can anyone tell me how to get an SVG file to work in QGIS? | 2014/08/20 | [
"https://gis.stackexchange.com/questions/111197",
"https://gis.stackexchange.com",
"https://gis.stackexchange.com/users/35019/"
] | Here are points in the table of contents:
Here's what my SVG that I downloaded from some website looks like to Windows Explorer in my downloads folder:
And what it looks like in IE:
Now double-click your point layer to open the layer properties
* choose the Simple Marker
* then from the 'symbol layer type' drop-down in the upper-right, choose "SVG"
Now choose the little ellipse (browse button) below the SVG Groups panel, and navigate to your SVG you want to use as the symbol:
Now you're SVG is set as the symbol for your points, and you can adjust the size, etc:
And here's the result on the map:
 | Once you had created the symbol using svg. Create the qml for same symbol and keep along with the shape file. next time whenever you load the same shape file it will take the symbology itself . |
30,298 | The crew escapes from these behemoths shortly before arriving on the island chain with Bellamy.
[](https://i.stack.imgur.com/YCpKH.png) | 2016/03/07 | [
"https://anime.stackexchange.com/questions/30298",
"https://anime.stackexchange.com",
"https://anime.stackexchange.com/users/4512/"
] | These are shadows, not monsters. These are explained by the fact that Sky Island is so high up in the air, the distance that the shadow is travelling is very far, making shadows cast very large.
Here you can see the same effect where Luffy's shadow is seen:
[](https://i.stack.imgur.com/66vYE.jpg) | skypien giants i thing almost the same as the oes from the florian tryangle the spear and there is no way a shadow in the sea and the shadow above is in the air these were throwing spears unless the things at the florian triangles were shadows.but they still may be shadows who knows they had wings. |
483,458 | >
> He couldn't even enjoy the school holidays and spent his time moping **around** the house.
>
>
>
Is the word "around" in the above sentence used as a preposition or as an adverb?
I think it is used as a preposition. However, others disagree. | 2019/01/30 | [
"https://english.stackexchange.com/questions/483458",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/334221/"
] | It's hard to classify. My guess is that "around" is part of the verb "mope around". If it were a preposition, it ought to be okay to say \*"Around what did he mope?" or \*"the house around which he moped". If it were an adverb, it ought to be possible to shift it to a different position: \*"He moped the house around." | >
> *He couldn't even enjoy the school holidays and spent his time moping*
> *around the house*.
>
>
>
I'd say that "around" is a preposition functioning as head of the preposition phrase "around the house", with the noun phrase "the house" as its complement.
The PP "around the house" is a complement licensed by "moping", and hence "moping around the house" is a syntactic constituent with "moping" as head and the PP "around the house" as its complement.
But "moping around" is not a constituent at word level: it’s a VP. Verb is a word category, like noun, adjective, etc., and it’s “moping” that is a verb: this is the word that takes verbal inflections. So we have [1] not [2]:
[1] They were moping around the house.
[2] \*They were mope arounding the house. |
328,107 | I'd like to use 'Dana' for a girl's name and know how Americans pronounce 'Dana'.
Do Americans pronounce 'Dana' as 'Dayna' or as 'Dahna'? | 2022/11/27 | [
"https://ell.stackexchange.com/questions/328107",
"https://ell.stackexchange.com",
"https://ell.stackexchange.com/users/165124/"
] | I think we have a tomayto, tomahto here.
The US would seem to go with dayna, Brits would say dahna.
Maybe it's because of the Eurovision winner from Ireland [or, as mentioned in comments, the later one from Israel], but I don't know how much this would still influence younger people.
It does appear to be an Irish name, and [Wiktionary](https://en.wiktionary.org/wiki/d%C3%A1na) give the Irish IPA as ˈd̪ˠæːnˠə, which, as I don't speak IPA at all, I fed into an [online reader](http://ipa-reader.xyz)
Rather amusingly, the American voices pronounce this IPA as 'dayna' & the British ones say 'dahna'.\*
*Late edit.* Following gotube's link to [Wikipedia](https://en.wikipedia.org/wiki/Dana_(given_name)), it seems that the US considers this to be a name of Persian origin. Brits would consider it Irish - from a completely different route. The names then could be thought of as being unrelated, merely spelled the same, with each of the US & UK having their 'own origin' & therefore own pronunciation.
\*Which reinforces why I always claim IPA is pretty much useless for teaching actual pronunciation, uninfluenced by accent :\ | Among English speakers, it's pronounced DAY-nah /deinə/.
[Wikipedia](https://en.wikipedia.org/wiki/Dana_(given_name)) agrees.
If it's a name in other languages, it's more likely pronounced /dana/, but I don't know if any other languages use it as a given name. |
41,744,922 | I have placed icon at current location. [pic-1.png](https://i.stack.imgur.com/HWtV5.png)
I want to place multiple images for current location like [pic-2.png](https://i.stack.imgur.com/THr0F.png)
**1-** Required face icon at current location.
**2-** Required red circle around face icon with pulsating effect. If we zoom in /zoom out map then I need no movement in red circle. Red circle will always show around face icon with same size.
**3-** Required home icon at top (around 100 px above red circle) with same requirement as point 2. | 2017/01/19 | [
"https://Stackoverflow.com/questions/41744922",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/6840452/"
] | If you don't want any movement in circle on zoom in/out then you can make a '.png' of complete image like 'pic-2.png' and set it on current location. | 1. If first time and you enable request location the face icon will in center view. After that you can transfer the curent location to coordinates of view and movement if have any movement of curent location.
2. same 1
3. change image if need |
31,296,334 | Is there a Tableau Desktop executable inside the Tableau server installation.
I have a system where Tableau server in Cloud and would want to use Tableau Desktop in the same server? Is that feasible? | 2015/07/08 | [
"https://Stackoverflow.com/questions/31296334",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/347494/"
] | At my previous organization, we always had a desktop version installed on the VM running our tableau server. This was useful for making connections to data sources that required firewall rules since the VM's IP was static. Then extracts could scheduled for refreshes.
So yes, it is feasable, but like others, it is a separate product. | As others mentioned, Tableau Desktop and Server are separate products and have separate executable. We used to have Tableau desktop installed on Server to publish extracts and manage our extracts which were developed using API |
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