Same here. I've been a pretty avid reader since 1999 but it wasn't until much later that I eventually decided to get a login. I still read a lot and post very little. I guess you're right, this place is kind of intimidating.
Ah Slashdot, how often I have read you while waiting for some calculation to finish... Keep the good work going, guys.
IIRC from Dyson's book, though, the damper was working as long as all bombs explode as planned. One dud was okay, but two consecutive duds would put the damper oscillation out of phase, which would induce huge stresses on the vessel structure resulting in its destruction. Two duds is not something which seems that unlikely to me.
Both Bill Gates and Steve Jobs dropped out of university. There is a huge difference between doing that and dropping out of school. Add to this that both Bill Gates and Steve Jobs actually had sensible projects in their hands, not a phoney idea some moron is stupid enough to fund.
Acroread is an awfully bloated piece of software. Back in my early days with Linux (around 1997), I tried xpdf, but it seemed to be unable to correctly render many pdf files. Recently, I tried it again and it has changed a lot. It works flawlessly and as an avid LaTeX+Beamer user, I find it very, very useful. Who needs Adobe spyware anymore ?
Oh, and BTW, I switched from Firefox 1.5.x to Firefox 2.0.0 on my old 2002 iBook with 384MB RAM, which still runs 10.2.8 (I know...) and found it significantly sluggisher...
I'm a plasma physicist and I work in the domain of radiofrequency waves propagation and absorption in fusion plasmas. I've been busy developping a code that solves the Maxwell's equations, which are equivalent to the wave equation (3-D full-wave calculation). The case of a plasma is tricky because it both time *and* space dispersive.
I won't be able to even start explaining this stuff in this post, but my code uses finite elements for the radial direction and Fourier decompositions for the two periodic directions of a fusion device. These numerical methods work well. I also know finite difference codes which work well. So, I think you should look a bit harder, because FE or FD methods usually do the trick, even for "variable wave speed at different points in the domain"... Regarding the boundary conditions, well, you'd better be very careful, because they will usually completely determine the solution. Again, it is my experience that Finite elements are well adapted to this task but you'll have to do some research.
Finally, for the vizualisation, matplotlib and vtk work for me.
First, try to determine and explain more precisely what it is you want to do: "to obtain good numerical approximations to the classic second-order wave equation, preferably in three space dimensions" sounds a but vague. Pick up the right textbooks, scientific journals, learn, exchange with the community. I know my post sounds a bit patronizing but this is science, and this kind of effort takes dedication, time and patience. I think Slashdot and Google are hardly the right places to start...
Sadly, every time I see a post regarding yet another blow to the civil rights committed by a US governement agency, the sentence "Quis custodiet ipsos custodes ?" pops to my mind.
Because you can't comb a sphere... In other words, because Maxwell's equations require any magnetic field to have zero divergence, which is not possible on a sphere.
This is a question I've asked myself several times. Can you really get eye problems because you stare at something which is too bright or too dark, or because you read under insufficient lighting, or because you spend pretty much your whole days and nights in front of your computer ? I mean, getting eye fatigue, sure, but I don't think I've ever seen any study showing that you could actually cause irreversible damage to your eyes by doing this. Does anyone have any source that would prove me wrong ?
Ugh, I hate it when writers try to look smart by throwing french expressions. Even without being a grammar nazi, "beaucoup expensive" is completely incorrect. "très expensive" would have been better but, hey, I guess it doesn't sound hip enough... I haven't finished TFA, but this doesn't bode too well.
Granted, but the problem is that you're the one who needs to take action to have them remove the picture. Not the other way around, i.e. they don't ask you for the permission to put it online (I don't know how they could do that practically, but this is beyond my point). That means you'll have to check periodically they didn't add pictures on which, say, your house appears. What's more, we're talking about Google, but tommorrow, Verizon may decide to do the same, and also Microsoft... So, even though it's theoretically possible for you to have pictures regarding your private stuff removed, soon enough, you won't be able to cope with it.
Talking about Slashdot, has there been some change in the tagging, recentely ? I mean, not long ago, it the subject was any question e.g. "Is Linux ready for the desktop ?". The tags would invariably be: yes, no, maybe, wtf... But I've noticed that now, it seems to make (a little) more sense... I guess I could have checked out the FAQs about this but hey, this is/.
Geez, how many times does this have to be repeated: Fortran isn't dead. Not by a long shot. Fortran 77, IV may still be around for maintenance, as you write, but Fortran 90, 95 and 2003 are still heavily used in scientific programming. About 10 years ago, I started working in physics and some people would always explain how everybody would soon make program in C++, even in science. Well, guess what, it hasn't happened. Why not ? Because as a scientist, your job is to focus on, well, science and the programming language is just a means. You don't want to spend your days looking for memory leaks, coding hacks and whatnot.
As a matter of fact, back then, I was a C fan, and I thought everything needed to be in C. So, I was working on this ugly fortran 77 code I had been given, and I decided to rewrite it in C. It took some time but eventually, it worked. I compiled it, ran it on this vectorial Cray and... although the results were the same as in Fortran, the performance was significantly poorer. In this case, the problem was the cache hit ratio, which was larger in my C code than in the original Fortran codee. In fact, the Cray Fortran compiler had done a better job than me at taking care of the memory, given the underlying architecture. Now, I grant that by working hard on the C source, I could probably have done as well, maybe even better, than Fortran. But, hey, this was not my job and from this day, I decided I would stick to Fortran for my research codes.
In other words, they threw up their hands and surrendered. Yeah, well, your post confirms that after 10^15 times, this joke still isn't funny... but we'll never tire of it, will we ?
Parent poster has been unfairly modded as troll. There definitely should be a way to mod down a submission. I mean, come on, a little irony can't hurt but the sentence "These days, Brazil is no longer just on the map for it's fine coffee and martial arts" is outright offensive.
And no, I'm not from Brazil.
Yes, I know this is Slashdot. But I'm a geek and a passionate marathon runner as well...
There's a big difference between running on a treadmill and on a road (besides the boring factor): the relative wind resistance you experience when you move has a very significant impact on your speed. A rule of thumb is that you have to subtract about 1 km/h to your treadmill speed in order to have an idea on how fast you can go on the road.
a tritium-deuterium reaction is more preferable for future reactors, but the tritium is refined from the deuterium Not sure what you mean by that. Right now, Tritium comes from fission reactors (essentially from Canada, I think). Hopefully, there'll be no need to input Tritium in a commercial D-T reactor, only Deuterium and Lithium (which yields Tritium under neutron radiation). But that's a concept which remains to be tested (this is planned to be tried on Iter). And as much as I'm enthusiastic about fusion (I work in the field), there's still a long road ahead. So I guess it all depends on what you call a "terribly long" time.
Raw materials -- He3 (as fusion fuel) is one possibility
As much as I love this idea, I have to say that I'm not too optimistic: He-3 plasmas need to be insanely hot to get sufficient output from the fusion reactions and at these temperatures (around 100keV, IRC), the plasma will collapse from synchrotron + bremsstrahlung radiation. Now, suppose you've found a way around this problem. Another issue you'll have to deal with is the absence of neutrons (BTW, He-3 fusion is not really aneutronic, but that's beyond my point). Without neutrons, the heat load will be entirely on the inner surface of the reactor. No material is even remotely capable of handling such a flux. OTOH, neutrons (from D-T fusion) may be nasty for a lot of reasons, but they will distribute the heat in the metal volume (from the neutron-metal interactions), making water cooling possible.
So, in a word, D-T fusion is not there yet, but He-3 fusion is very very far away, if at all possible.
http://en.wikipedia.org/wiki/Gabriel_Knight
Gabriel Knight (by Sierra). I've spent quite a few hours on these. The puzzles were pretty tricky. Amazingly (or not), the version I enjoyed most was the first one. Despite much simpler graphisms, it had a great atmosphere. The second one was not very good, IMHO. I liked the scenario of the third one, although my machine at the time at a hard time coping with the 3D rendering...
Still, I'd buy a sequel without any hesitation.
Slashdot Mirror
will it run on the old G4's ?
Same here. I've been a pretty avid reader since 1999 but it wasn't until much later that I eventually decided to get a login. I still read a lot and post very little. I guess you're right, this place is kind of intimidating.
Ah Slashdot, how often I have read you while waiting for some calculation to finish... Keep the good work going, guys.
IIRC from Dyson's book, though, the damper was working as long as all bombs explode as planned. One dud was okay, but two consecutive duds would put the damper oscillation out of phase, which would induce huge stresses on the vessel structure resulting in its destruction. Two duds is not something which seems that unlikely to me.
Acroread is an awfully bloated piece of software. Back in my early days with Linux (around 1997), I tried xpdf, but it seemed to be unable to correctly render many pdf files. Recently, I tried it again and it has changed a lot. It works flawlessly and as an avid LaTeX+Beamer user, I find it very, very useful. Who needs Adobe spyware anymore ?
Oh, and BTW, I switched from Firefox 1.5.x to Firefox 2.0.0 on my old 2002 iBook with 384MB RAM, which still runs 10.2.8 (I know...) and found it significantly sluggisher...
I'm a plasma physicist and I work in the domain of radiofrequency waves propagation and absorption in fusion plasmas. I've been busy developping a code that solves the Maxwell's equations, which are equivalent to the wave equation (3-D full-wave calculation). The case of a plasma is tricky because it both time *and* space dispersive.
I won't be able to even start explaining this stuff in this post, but my code uses finite elements for the radial direction and Fourier decompositions for the two periodic directions of a fusion device. These numerical methods work well. I also know finite difference codes which work well. So, I think you should look a bit harder, because FE or FD methods usually do the trick, even for "variable wave speed at different points in the domain"... Regarding the boundary conditions, well, you'd better be very careful, because they will usually completely determine the solution. Again, it is my experience that Finite elements are well adapted to this task but you'll have to do some research.
Finally, for the vizualisation, matplotlib and vtk work for me.
First, try to determine and explain more precisely what it is you want to do: "to obtain good numerical approximations to the classic second-order wave equation, preferably in three space dimensions" sounds a but vague. Pick up the right textbooks, scientific journals, learn, exchange with the community. I know my post sounds a bit patronizing but this is science, and this kind of effort takes dedication, time and patience. I think Slashdot and Google are hardly the right places to start...
Sadly, every time I see a post regarding yet another blow to the civil rights committed by a US governement agency, the sentence "Quis custodiet ipsos custodes ?" pops to my mind.
Because you can't comb a sphere... In other words, because Maxwell's equations require any magnetic field to have zero divergence, which is not possible on a sphere.
This is a question I've asked myself several times. Can you really get eye problems because you stare at something which is too bright or too dark, or because you read under insufficient lighting, or because you spend pretty much your whole days and nights in front of your computer ? I mean, getting eye fatigue, sure, but I don't think I've ever seen any study showing that you could actually cause irreversible damage to your eyes by doing this. Does anyone have any source that would prove me wrong ?
Damn straight !! Geez, won't anybody mod this Anonymous Coward message up. Please ?
Ugh, I hate it when writers try to look smart by throwing french expressions. Even without being a grammar nazi, "beaucoup expensive" is completely incorrect. "très expensive" would have been better but, hey, I guess it doesn't sound hip enough... I haven't finished TFA, but this doesn't bode too well.
What, there are several of us, now ?
P.S.: Hint: look at my username
Granted, but the problem is that you're the one who needs to take action to have them remove the picture. Not the other way around, i.e. they don't ask you for the permission to put it online (I don't know how they could do that practically, but this is beyond my point). That means you'll have to check periodically they didn't add pictures on which, say, your house appears. What's more, we're talking about Google, but tommorrow, Verizon may decide to do the same, and also Microsoft... So, even though it's theoretically possible for you to have pictures regarding your private stuff removed, soon enough, you won't be able to cope with it.
Talking about Slashdot, has there been some change in the tagging, recentely ? I mean, not long ago, it the subject was any question e.g. "Is Linux ready for the desktop ?". The tags would invariably be: yes, no, maybe, wtf... But I've noticed that now, it seems to make (a little) more sense... I guess I could have checked out the FAQs about this but hey, this is /.
Geez, how many times does this have to be repeated: Fortran isn't dead. Not by a long shot. Fortran 77, IV may still be around for maintenance, as you write, but Fortran 90, 95 and 2003 are still heavily used in scientific programming. About 10 years ago, I started working in physics and some people would always explain how everybody would soon make program in C++, even in science. Well, guess what, it hasn't happened. Why not ? Because as a scientist, your job is to focus on, well, science and the programming language is just a means. You don't want to spend your days looking for memory leaks, coding hacks and whatnot.
As a matter of fact, back then, I was a C fan, and I thought everything needed to be in C. So, I was working on this ugly fortran 77 code I had been given, and I decided to rewrite it in C. It took some time but eventually, it worked. I compiled it, ran it on this vectorial Cray and... although the results were the same as in Fortran, the performance was significantly poorer. In this case, the problem was the cache hit ratio, which was larger in my C code than in the original Fortran codee. In fact, the Cray Fortran compiler had done a better job than me at taking care of the memory, given the underlying architecture. Now, I grant that by working hard on the C source, I could probably have done as well, maybe even better, than Fortran. But, hey, this was not my job and from this day, I decided I would stick to Fortran for my research codes.
Parent poster has been unfairly modded as troll. There definitely should be a way to mod down a submission. I mean, come on, a little irony can't hurt but the sentence "These days, Brazil is no longer just on the map for it's fine coffee and martial arts" is outright offensive.
And no, I'm not from Brazil.
Yes, I know this is Slashdot. But I'm a geek and a passionate marathon runner as well...
There's a big difference between running on a treadmill and on a road (besides the boring factor): the relative wind resistance you experience when you move has a very significant impact on your speed. A rule of thumb is that you have to subtract about 1 km/h to your treadmill speed in order to have an idea on how fast you can go on the road.
As much as I love this idea, I have to say that I'm not too optimistic: He-3 plasmas need to be insanely hot to get sufficient output from the fusion reactions and at these temperatures (around 100keV, IRC), the plasma will collapse from synchrotron + bremsstrahlung radiation. Now, suppose you've found a way around this problem. Another issue you'll have to deal with is the absence of neutrons (BTW, He-3 fusion is not really aneutronic, but that's beyond my point). Without neutrons, the heat load will be entirely on the inner surface of the reactor. No material is even remotely capable of handling such a flux. OTOH, neutrons (from D-T fusion) may be nasty for a lot of reasons, but they will distribute the heat in the metal volume (from the neutron-metal interactions), making water cooling possible.
So, in a word, D-T fusion is not there yet, but He-3 fusion is very very far away, if at all possible.
This comment shouldn't have been modded Funny.
s/magentic/magenta/
There, fixed it for ya.
Correlation ain't causality
'nuf said.
http://en.wikipedia.org/wiki/Gabriel_Knight
Gabriel Knight (by Sierra). I've spent quite a few hours on these. The puzzles were pretty tricky. Amazingly (or not), the version I enjoyed most was the first one. Despite much simpler graphisms, it had a great atmosphere. The second one was not very good, IMHO. I liked the scenario of the third one, although my machine at the time at a hard time coping with the 3D rendering...
Still, I'd buy a sequel without any hesitation.