That minix is a useful low-overhead OSS operating system is incidental. the reason it exists is to provide a real base for taunenbaums books on operating systems which are greatly enhanced by the inclusion of the source code for a real working operating system. This has always been the primary goal of minix.
The third edition of the book is coming out, hence the third release of minix is coming out in lockstep.
the Maxima computer algebra system is a decendent of DOE Macsyma, which is from the 60s and one of the first computer algebra systems. it is a really great project. http://maxima.sf.net/
The x87 is a stack machine and it was a major leap forward at the time when floating point loops tended to be hand-coded assembly, it was like having a little hardware forth interpreter. (sort of.. maybe..)
but the main problems are that is that it is very difficult to write an optimizing compiler that spits out code suitable to run on a stack machine, there are lots of algorithms for optimal register selection, but when your registers move around with every operation, things become considerably more difficult.
The other problem is that it does not parallelize well. modern CPUs are all about superscalar architectures where they have multiple execution units that try to execute non-conflicting instructions concurrently. since the x87 is stack based, pretty much all operations act on the top of the stack and the top only. this means that every floating point instruction conflicts with each other and you are forced to execute them in sequence. modern CPUs have taken some steps to alleviate this, but it is a non-trivial problem to solve, especially when you want to do it as fast as possible in your instruction scheduler.
the x87 is so broken but luckily, we are no longer shackled to it.
part of the x86-64 spec is full support for SSE and in fact, the SSE instructions are meant to completly replace the use of the x87, which is only there for legacy support.
I think a lot of the gain of x86-64 will be from being able to _count_ on sse support and use it when compiling in addition to just its 64bit nature.
although, a lot of distros are dropping support (at least optionally) for pre-SSE cpus to always compile with it enabled so we are already starting to see some of the benefits.
I am really glad there are 8 different teams working on it. scientists collaborating with 8 different languages and ideas on what should be done will ensure the failure of a mediocre project.
This is part of the reason the ISS sucks so much, since the US and Russia couldn't agree on what orbit to put it in, it ended up in a bad for both orbit. Dogshed discussions are bad enough in software teams, imagine if one's national pride were riding on the issue.
competition is what drove the space race in the first place and it works very well as a motivator.
Space elevators will come. but a big international project won't work right now. but lots of nations developing their own space programs will get us closer to a point where the international cooperation needed will become possible.
no. they have to stop calling you if you ask them too.
_no one_ not charities, not surveys, not prior business relationships, not even creditors can call you if you ask them not to.
the magic phrase is "take me off your list". don't phrase it any differently or try to be more polite about it, because they can weasel out of it saying they didn't understand you wanted to be removed from their list.
just say "take me off your list" and if they do anything other than say okay and hang up immediatly and never call you again then they are in trouble.
the combination of the DNC list and learning that phrase has gotten me down to zero unsolicited phone calls. from 4-5 a day.
No, the half facing deep space will eventually reach cold temperatures, the half facing the sun will reach hotter temperatures.
asuming your ship is roundish and has roughly similar albedo to earth, if you rotate it, it will reach somewhere near the average temperature of earth in our local neihborhood.
One could even paint one half white and one half black any vary the rate of rotation to heat up or cool down the craft as appropriate. you wouldn't even need to use any reaction mass as once you are up to speed you can have a constant angular momentum and just change your mass distrubtion in your ship to speed down and slow up your rotation. if you are also using the rotation for artificial gravity, expect some odd effects:)
there are probably easier ways to achieve good temperature control.
You know, every time this topic comes up, I see many more responses admonishing the slashdot community for stealing music than people that actually advocate stealing it in the first place. You are part of the community to, so obviously the slashdot community is at least conflicted on the issue if not against stealing outright so blanket generalizations don't really apply.
Just monitor the traffic to see who is actually using the link. you should be able to figure it out from their IP address or their browsing habits. Chances are it is whoever set up the link. You may have to use one of the many WEP crackers, but that shouldn't present a problem.
If no one ever seems to be using it, it is possible you are picking up someones laptop with a built in 802 card that automatically enables without the user even knowing.
Rather than hire known B directors and writers
on
Sci-Fi on the Cheap
·
· Score: 4, Insightful
They should sponsor individuals just out of film/writing school with a vision who would be willing to work on a small budget to get their chance. Sure they might end up with some failures, but they also might produce some gems. All in all I think it would be a better investment than consistant crap.
Yeah, When you have wireless internet available most everywhere. it is hard to make a point for local storage in a laptop at all. I just use mine as ssh and X11 clients to my big machine safely tucked away under a desk somewhere. You can even do this with windows nowadays with remote desktop or vnc. The best part about making the laptop 'dumb' is you no longer need to worry about it. if it gets swiped or sat upon, it sucks, but does not affect your life or workflow much if you can find another laptop and drop your dumb client on it. You can get really cheap laptops that run X11 full speed and can do 802.11 on ebay. My favorite is the IBM thinkpad 701c. it is only a 486, but is quite neat with its expanding keyboard and is more than powerful enough to run ssh. (but X11 is pushing it)
There are a lot of microcontroller/hardware programming contests.
It is programming on a small scale, but it also involves building some hardware. If you are burnt out on programming, working with your hands on real hardware is a great way to relax. It is also fun to work on the nitty gritty low level stuff if you are used to high-level languages. (or vice versa). When it comes to languages it is Haskell or Assembly for me, anything in between would just be mediocre:)
There are a lot of PIC, Amtel, or other microcontroller contests out there.
No language restrictions, very interesting problems. quite prestigious to win. it is great!
The only downside is that it is only once a year. It is fun to do it in a language you don't know as a forced crash course too if you don't expect to win.:)
In a limited way, a trivial case of this was proven. If you have a timelike wormhole (one end is in the past compared to the other). and you toss a billiard ball into the future end, there is _no_ solution for any arangement of the ball and the wormhole that allows the billard ball to intersect itself in a way that keeps it from falling into the wormhole in the future.
note, that there is nothing wrong with the ball being sent back in time, it just can't self intersect in a way that keeps it from going back in the first place, there just doesn't exist a configuration that allows this. However, there are solutions where the ball self intersects in such a way that _causes_ it to enter the wormhole. wacky stuff. how one would arrange such a thing is another matter.
That said, does anyone have a link to an original paper on this result? I mean, it is a common psuedotheory in physics, I am wondering if some new evidence has been discovered recently or a reporter was just repeating some noodling of someone partaking in mental masturbation.
Hopefully they incorperate the great ideas of lotus improv. Apple just might have the power to pull it off and the original source is even in objective C as it was originally written for NeXTSTEP.
Each cell unit basically is a DSP actually. That is what fast vector and matrix math is used for. The sound design of the PS3 makes a lot of sense actually, might as well have a generalized cell than a dedicated DSP, the differences are slight and there is a lot to be gained by consistancy for the programers.
The actual reason barns are traditionally red is that they were painted with iron oxide (rust) because it killed moss and mold. At least at the beginning.
All CCDs just measure intensity, a "color" ccd is just 3 sensors with red, green, and blue filters over them. Handy for humans, but pretty silly from a science perspective. it cuts your resolution into a third and fixes you with a not very useful subset of the spectrum. there are much much more interesting things you can do with spectrometry which is why you have a single awesome plain CCD, and a wheel with lots of differet filters on it for lots of interesting frequencies. this is strictly superior to color CCDs in many ways. By looking at the right lines, you can determine the precise molecular make-up of matter.
For some reason people think 'synthesising' a color image is somehow wrong or untrue. this is _exactly_ how your color cameras work, except the synthesis is limited and done inside the camera. it makes much more sense to send back the raw data and do the synthesis on earth for these probes.
There is no need to understand morse. it would just be a more efficient input method. Inside the phone it would be tranlated to text and messages from other people would appear as text just like any other. Of course, cell phone buttons would be horrible to morse on. You would want something like a capacitive vibroplex. it could be a little protrusion out of the bottom of the phone, the rest of the space could be dedicated to screen.
Umm.. Centrifugal force is quite real and describes exactly the effect I am talking about. You are probably thinking of centripetal force, which is exerted on the galinstan by the walls of its container, which would be another accurate but less useful in this context way of putting things since you probably want to think of the mirror as stationary for doing the math and intuitively thinking about the shape of the mirror.
I am not sure where the persistant myth that centrifugal does not exist came from, but it is quite bothersome. It is a well established term with a precise meaning. I mean, it exists due to a coordinate transform, but that doesn't make the math and results any less valid!
Yeah, galinstan is liquid at room temperature and quite safe (compared to mercury). I have a vial of it on my desk. fun stuff.
make your own, it is 68.5% Ga, 21.5% In, 10% Sn or you can buy it online.
A cool application is to make a _perfect_ parabolic mirror. You do this by spinning a puddle of it. The centrifugal force pulls it against the sides and is countered by gravity pulling down the center making a perfect mirror for a tesescope always pointing exactly straight up.
Slashdot Mirror
That minix is a useful low-overhead OSS operating system is incidental. the reason it exists is to provide a real base for taunenbaums books on operating systems which are greatly enhanced by the inclusion of the source code for a real working operating system. This has always been the primary goal of minix.
0 ,1144,0131429388,00.html
The third edition of the book is coming out, hence the third release of minix is coming out in lockstep.
http://vig.prenhall.com/catalog/academic/product/
the Maxima computer algebra system is a decendent of DOE Macsyma, which is from the 60s and one of the first computer algebra systems. it is a really great project. http://maxima.sf.net/
The x87 is a stack machine and it was a major leap forward at the time when floating point loops tended to be hand-coded assembly, it was like having a little hardware forth interpreter. (sort of.. maybe..)
but the main problems are that is that it is very difficult to write an optimizing compiler that spits out code suitable to run on a stack machine, there are lots of algorithms for optimal register selection, but when your registers move around with every operation, things become considerably more difficult.
The other problem is that it does not parallelize well. modern CPUs are all about superscalar architectures where they have multiple execution units that try to execute non-conflicting instructions concurrently. since the x87 is stack based, pretty much all operations act on the top of the stack and the top only. this means that every floating point instruction conflicts with each other and you are forced to execute them in sequence. modern CPUs have taken some steps to alleviate this, but it is a non-trivial problem to solve, especially when you want to do it as fast as possible in your instruction scheduler.
the x87 is so broken but luckily, we are no longer shackled to it.
part of the x86-64 spec is full support for SSE and in fact, the SSE instructions are meant to completly replace the use of the x87, which is only there for legacy support.
I think a lot of the gain of x86-64 will be from being able to _count_ on sse support and use it when compiling in addition to just its 64bit nature.
although, a lot of distros are dropping support (at least optionally) for pre-SSE cpus to always compile with it enabled so we are already starting to see some of the benefits.
I am really glad there are 8 different teams working on it. scientists collaborating with 8 different languages and ideas on what should be done will ensure the failure of a mediocre project.
This is part of the reason the ISS sucks so much, since the US and Russia couldn't agree on what orbit to put it in, it ended up in a bad for both orbit. Dogshed discussions are bad enough in software teams, imagine if one's national pride were riding on the issue.
competition is what drove the space race in the first place and it works very well as a motivator.
Space elevators will come. but a big international project won't work right now. but lots of nations developing their own space programs will get us closer to a point where the international cooperation needed will become possible.
no. they have to stop calling you if you ask them too.
_no one_ not charities, not surveys, not prior business relationships, not even creditors can call you if you ask them not to.
the magic phrase is "take me off your list". don't phrase it any differently or try to be more polite about it, because they can weasel out of it saying they didn't understand you wanted to be removed from their list.
just say "take me off your list" and if they do anything other than say okay and hang up immediatly and never call you again then they are in trouble.
the combination of the DNC list and learning that phrase has gotten me down to zero unsolicited phone calls. from 4-5 a day.
and hold it with both hands and you have an original nintendo style controller with a/b and a d-pad. I am sure that is not an accident.
No, the half facing deep space will eventually reach cold temperatures, the half facing the sun will reach hotter temperatures.
:)
asuming your ship is roundish and has roughly similar albedo to earth, if you rotate it, it will reach somewhere near the average temperature of earth in our local neihborhood.
One could even paint one half white and one half black any vary the rate of rotation to heat up or cool down the craft as appropriate. you wouldn't even need to use any reaction mass as once you are up to speed you can have a constant angular momentum and just change your mass distrubtion in your ship to speed down and slow up your rotation. if you are also using the rotation for artificial gravity, expect some odd effects
there are probably easier ways to achieve good temperature control.
If you seem to know that it is within the range of statistical noise and even state so in the summary, then why post it as news?
You know, every time this topic comes up, I see many more responses admonishing the slashdot community for stealing music than people that actually advocate stealing it in the first place. You are part of the community to, so obviously the slashdot community is at least conflicted on the issue if not against stealing outright so blanket generalizations don't really apply.
Just monitor the traffic to see who is actually using the link. you should be able to figure it out from their IP address or their browsing habits. Chances are it is whoever set up the link. You may have to use one of the many WEP crackers, but that shouldn't present a problem.
If no one ever seems to be using it, it is possible you are picking up someones laptop with a built in 802 card that automatically enables without the user even knowing.
They should sponsor individuals just out of film/writing school with a vision who would be willing to work on a small budget to get their chance. Sure they might end up with some failures, but they also might produce some gems. All in all I think it would be a better investment than consistant crap.
Yeah, When you have wireless internet available most everywhere. it is hard to make a point for local storage in a laptop at all. I just use mine as ssh and X11 clients to my big machine safely tucked away under a desk somewhere. You can even do this with windows nowadays with remote desktop or vnc. The best part about making the laptop 'dumb' is you no longer need to worry about it. if it gets swiped or sat upon, it sucks, but does not affect your life or workflow much if you can find another laptop and drop your dumb client on it. You can get really cheap laptops that run X11 full speed and can do 802.11 on ebay. My favorite is the IBM thinkpad 701c. it is only a 486, but is quite neat with its expanding keyboard and is more than powerful enough to run ssh. (but X11 is pushing it)
There are a lot of microcontroller/hardware programming contests.
:)
It is programming on a small scale, but it also involves building some hardware. If you are burnt out on programming, working with your hands on real hardware is a great way to relax. It is also fun to work on the nitty gritty low level stuff if you are used to high-level languages. (or vice versa). When it comes to languages it is Haskell or Assembly for me, anything in between would just be mediocre
There are a lot of PIC, Amtel, or other microcontroller contests out there.
http://www.circuitcellar.com/ hosts regular contests with big cash prizes
http://piclist.com/techref/piclist/pcbcontest.htm is a monthly PIC one.
anyone have any other good ones?
http://icfpc.plt-scheme.org/
:)
No language restrictions, very interesting problems. quite prestigious to win. it is great!
The only downside is that it is only once a year. It is fun to do it in a language you don't know as a forced crash course too if you don't expect to win.
It starts this weekend! so start preparing.
In a limited way, a trivial case of this was proven. If you have a timelike wormhole (one end is in the past compared to the other). and you toss a billiard ball into the future end, there is _no_ solution for any arangement of the ball and the wormhole that allows the billard ball to intersect itself in a way that keeps it from falling into the wormhole in the future.
note, that there is nothing wrong with the ball being sent back in time, it just can't self intersect in a way that keeps it from going back in the first place, there just doesn't exist a configuration that allows this. However, there are solutions where the ball self intersects in such a way that _causes_ it to enter the wormhole. wacky stuff. how one would arrange such a thing is another matter.
That said, does anyone have a link to an original paper on this result? I mean, it is a common psuedotheory in physics, I am wondering if some new evidence has been discovered recently or a reporter was just repeating some noodling of someone partaking in mental masturbation.
Hopefully they incorperate the great ideas of lotus improv. Apple just might have the power to pull it off and the original source is even in objective C as it was originally written for NeXTSTEP.
Lotus Improv
Since MacOSX is very compatable with NeXTSTEP it should be a straightforward port.
Each cell unit basically is a DSP actually. That is what fast vector and matrix math is used for. The sound design of the PS3 makes a lot of sense actually, might as well have a generalized cell than a dedicated DSP, the differences are slight and there is a lot to be gained by consistancy for the programers.
The actual reason barns are traditionally red is that they were painted with iron oxide (rust) because it killed moss and mold. At least at the beginning.
There is no such thing as a color CCD.
There is no such thing as a color CCD.
All CCDs just measure intensity, a "color" ccd is just 3 sensors with red, green, and blue filters over them. Handy for humans, but pretty silly from a science perspective. it cuts your resolution into a third and fixes you with a not very useful subset of the spectrum. there are much much more interesting things you can do with spectrometry which is why you have a single awesome plain CCD, and a wheel with lots of differet filters on it for lots of interesting frequencies. this is strictly superior to color CCDs in many ways. By looking at the right lines, you can determine the precise molecular make-up of matter.
For some reason people think 'synthesising' a color image is somehow wrong or untrue. this is _exactly_ how your color cameras work, except the synthesis is limited and done inside the camera. it makes much more sense to send back the raw data and do the synthesis on earth for these probes.
There is no need to understand morse. it would just be a more efficient input method. Inside the phone it would be tranlated to text and messages from other people would appear as text just like any other. Of course, cell phone buttons would be horrible to morse on. You would want something like a capacitive vibroplex. it could be a little protrusion out of the bottom of the phone, the rest of the space could be dedicated to screen.
Your post was appropriatly witty and funny. It is I who have been awake too long. I apologize :)
Umm.. Centrifugal force is quite real and describes exactly the effect I am talking about. You are probably thinking of centripetal force, which is exerted on the galinstan by the walls of its container, which would be another accurate but less useful in this context way of putting things since you probably want to think of the mirror as stationary for doing the math and intuitively thinking about the shape of the mirror.
http://en.wikipedia.org/wiki/Centrifugal_force
I am not sure where the persistant myth that centrifugal does not exist came from, but it is quite bothersome. It is a well established term with a precise meaning. I mean, it exists due to a coordinate transform, but that doesn't make the math and results any less valid!
"Televisions are getting smaller and smaller, and bigger and bigger. Soon the market for the medium sized tv will disappear."
Yeah, galinstan is liquid at room temperature and quite safe (compared to mercury). I have a vial of it on my desk. fun stuff.
make your own, it is 68.5% Ga, 21.5% In, 10% Sn or you can buy it online.
A cool application is to make a _perfect_ parabolic mirror. You do this by spinning a puddle of it. The centrifugal force pulls it against the sides and is countered by gravity pulling down the center making a perfect mirror for a tesescope always pointing exactly straight up.