IIRC, that idea went out when General Relativity came in.
The visible universe has enough matter and energy in it for complete curvature, as if it has the shape of a deformed 3-sphere. It could be the case that one or more dimensions is infinite, but then, there must be no matter there- because once there is a certain amount of matter there, it's going to curve back in on itself. Given the distribution of stars and some estimates of the age of the universe, we should actually be able to see this [and there are projects to looking into the extents of space on different sides of the globe and hoping to see the same thing]. What this means for us is, even if not all matter is visible, it is at least on the order of visible matter.
creation of increasingly complex organic molecules on a young Earth Well, yes and no. I feel this is a major hole. The complexity required for completely [ie, not virii] self-synthesizing organic molecules is of exponential order, and even considering the size and age of the universe, is such that life beginning by chance is not particularly likely. If we chose DNA as a convenient example [and it doesn't really matter, the math is the same regardless], and every atom in the universe were in fact a DNA base, and all of those bases were in equal proportions, combined with equal probability, and were close enough to interact, and thus they did; if the minimal complexity chain was a mere 142 bases, there would be only [4^142/(10^85)]=.3? probability that this chain would form somewhere. I am not a geneticist, but I'm willing to bet that the critical complexity required for an organism to reproduce is an order of magnitude larger, and remember of course that we don't actually have a whole universe of bases. No matter how you fudge these figures, you will never see any believable probability that life could ever begin.
But, evolution itself is not about life beginning, at all.
String theory is probably the only theory that really supports inflation. If the net energy in the universe is constant, then the net curvature must be constant, therefore it could only appear smaller if curvature were balanced between other dimensions.
My first thought after reading the article was, maybe it is?
the implication is perhaps more troubling. It suggests that there is a group of Russian hackers who, on their own, can disrupt the routine functioning of commerce, media, and government any time they want. If so, these hackers represent a stateless power -- a sort of private militia. But more than that, it potentially puts political power into the hands of an educated prolateriat. Is it worrying that I'd prefer my peers in Russia in control, over my own government?
from the summary:
Intel has quietly launched a new online community that it plans to use to take feedback and suggestions from OEMs and end users for new features in its vPro chips and management software. The article does not mention anything about this. In fact:
Intel envisions that the community will grow to allow users to get answers from other community members faster than Intel's support group can answer questions. is more like it. It's an attempt to connect people who know about Intel processors with people who want to know about them. Lets face it, if Intel wanted feedback or information about how best to proceed with chip design, there are plenty of places they could go and listen. No, Intel are NOT interested in listening to your ideas on optimising their chips, though I understand how such a skew might generate public interest.
Ah, ok. I wonder if there are people out there trying to fit libpurple to xchat or something, that would rock. Xchat really would make a great IM client. It would certainly be more natural for SILC than pidgin is.
iTunes has some nice features for navigating via metadata tags, but manages to fall short of working like a real relational database. So, if there are other criterion you need to organise music to, for whatever reason, you're out of luck. [Try to find me a baroque/classical/romantic fan who manages to access all their music through iTunes!] OTOH, a file system is a good abstraction that, if kept in order, can be manipulated at will.
Though the majority of what you do with your music on your computer is listen to it and move it to your portable music player, that is not the only thing. Others have pointed out the horror of trying to use iTunes with non-persistent distributed music libraries, consider how this is compounded with limited disk space, hence caching out music to removable media. Or how about other programs that need to interact with your media files?
Wait, xchat does IM? What protocols does it support?
If it does, I'd totally switch. I already use it for IRC. The best thing about it, I find, is that the list of people online is tied to the conversation window. If xchat does IM, then it has finally killed the silly separate contact windows introduced by Yahoo back before tabs became popular.
The Chaser have always seemed somewhat critical of Howard, but making fun of APEC is like making fun of Howard's mum.
At the very least, they won't pull Chaser's before the election, and might not be able to afterwards. It looks like we're in for some interesting viewing over the next couple of months!
What matters is what axioms you begin with. Existence or nonexistence of god could both yield consistent universes.
So, metaphysics provides no answers, and you've got to look at history for hints. Most people think that the inconsistency of major religions is proof that there can be no truth there. On the other hand, it's hard to believe that people can be THAT gullible. Maybe there are shards of fact in there, if we look close enough. Maybe the inconsistencies are in there to stop anyone with a brain from looking closer, and trying to discern truth through the millennia of lies.
Or maybe I'm wrong. It's an awkward twist to find motive for the sort of distortions of dogma that would be required to go from something believable to modern religion. Definitely worth more scrutiny, though, IMHO.
...don't seem to work very well in the case of variable wave speed at different points in the domain, which is exactly the case that I need. Look closer. Wave speed is a parameter in the DE, and all solution methods of linear DEs are local. If you treat the parameter as variable, it will be obvious what you need to do in both FEM and FDM.
What numerical methods do you use, and which programs do you find best suited to the task? Well, always fit the method to the problem. As usual, FEM if you've got an odd boundary conditions, FDM otherwise. And don't forget other methods like integral transforms and greens functions, which can simplify or complicate your problem to varying degrees. Mathematica and Maple are good for a lot of things, having features for symbolic manipulation. Of course, D/C/LISP/Python/your-favourite-language-here work well enough for the actual crunching.
How do you deal with stability issues, boundary/initial values, and other pitfalls? Stability issues: The best thing you can do is prove stability. See if you can fit backwards and forwards together a-la Crank-Nicholson, and check that for stability. Or, use something nicer like Runge-Kutta in the time domain.
Boundary/Initial Values: You do what you have to, I guess. That's a lot more problem specific. If you haven't got the standard initial-time/bounded space situation, you can approximate an unbounded region. It's a lot simpler than you would think, but you need to solve it for your specific problem. Bounded-time is different, but you can then do FDM in the time domain.
Other pitfalls: Stiffness can point to a flaw in your reasoning. Scaling is worth a try. Otherwise, there are always methods to deal with your specific problem. Talk to your friendly neighborhood mathematician.
Are there different methods for electromagnetic wave problems? I think they are usually easier with analytic methods. IANA electrodynamicist, but try a few things out.
Finally, when the numbers have all been crunched, how do you visualize your hard-earned data? Matplotlib is good if you work in Python. If your employer uses Matlab/Maple/Mathematica, use those. I find Matlab awkward, and Matplotlib is similar and has most of the same features.
I'd automatically say use finite difference, with a crank-nicholson scheme (for convergence), and gauss-seidel iteration. Here here! And for different wave rates, notice where the wave rates appear in the matrix. Best to derive by hand, keeping the wave rates as functions of position. If you've got weird boundary conditions you can't work out how to use yourself, take it to a numerical mathematician. Most of them have studied this stuff to death, and can give you good error estimations too.
And if the problem is significantly complex or you need more general solution, try a Greens function.
Just disable Javascript and whitelist pages that are reasonably safe. Nice in theory- but it isn't exactly low maintenance. You're going to get a call every couple of hours asking why site x won't work. And you can't put the old people in charge, because then you have to educate them on why you can't put every site you visit on the whitelist.
The Wii definitely works:) although a bare bones system with a flash drive for a system disk will work just as well (I think CDs are too noisy for this, myself).
I think the whole "dangers of dynamically typed language" was just a brain fart by the GP. For starters, it is off-topic, in an otherwise well put together post, simply suggesting that e is not as educated on the subject as e thinks e is. Move along, nothing to see here.
Plenty of mechanisms exist today that don't require Javascript. However, it's the content provider that ultimately decides what methods get used. I don't see many providers jumping on the no-Javascript bandwagon any time soon. What it comes down to is, for the foreseeable future, you're probably going to need Javascript in these facilities.
It sure is a hack. YouTube were an example pulled from the post, I didn't really want to point the finger at them specifically. And, I guess it is clichéd to complain about web developers not designing websites to work in environments where scripting is disabled, but that's really what it comes down to: there is no getting around this in the foreseeable future, so you can't just turn it off.
they'll probably want to watch YouTube videos of their offspring. YouTube uses Javascript to load the flash plugin. Silly, no? Unfortunately, we're stuck with Javascript for some time now. But, I like the other idea, not having write access to the media from which you boot off.
Animations and interactivity are always great- Mathematica, Maple, or Python + Matplotlib can be handy for this. If you have access to fluid or electrical system modelling software too, great. Otherwise, there is not a lot you can do. At the end of the day, there is only one way to learn to apply principals: a combination of reading and examining the ideas, and examples.
Some people have mentioned having the notes reproduced in PDF- I found I did much better in the university classes where notes were distributed rather than having to be copied down, because it leaves more time for meditation on the subject matter, and reduces needless duplication of work. I doubt it would work the same in high school, though.
Slashdot Mirror
IIRC, that idea went out when General Relativity came in.
The visible universe has enough matter and energy in it for complete curvature, as if it has the shape of a deformed 3-sphere. It could be the case that one or more dimensions is infinite, but then, there must be no matter there- because once there is a certain amount of matter there, it's going to curve back in on itself. Given the distribution of stars and some estimates of the age of the universe, we should actually be able to see this [and there are projects to looking into the extents of space on different sides of the globe and hoping to see the same thing]. What this means for us is, even if not all matter is visible, it is at least on the order of visible matter.
But, evolution itself is not about life beginning, at all.
http://distrowatch.com/stats.php?section=popularity
solid package requirements, automatic dependency resolution, alternative kernels [Hurd/Mach and kfreeBSD]
String theory is probably the only theory that really supports inflation. If the net energy in the universe is constant, then the net curvature must be constant, therefore it could only appear smaller if curvature were balanced between other dimensions.
Ah, ok. I wonder if there are people out there trying to fit libpurple to xchat or something, that would rock. Xchat really would make a great IM client. It would certainly be more natural for SILC than pidgin is.
best slashdot thread ever ;)
- iTunes has some nice features for navigating via metadata tags, but manages to fall short of working like a real relational database. So, if there are other criterion you need to organise music to, for whatever reason, you're out of luck. [Try to find me a baroque/classical/romantic fan who manages to access all their music through iTunes!] OTOH, a file system is a good abstraction that, if kept in order, can be manipulated at will.
- Though the majority of what you do with your music on your computer is listen to it and move it to your portable music player, that is not the only thing. Others have pointed out the horror of trying to use iTunes with non-persistent distributed music libraries, consider how this is compounded with limited disk space, hence caching out music to removable media. Or how about other programs that need to interact with your media files?
I'm over re-synching libraries and broken links.Wait, xchat does IM? What protocols does it support?
If it does, I'd totally switch. I already use it for IRC. The best thing about it, I find, is that the list of people online is tied to the conversation window. If xchat does IM, then it has finally killed the silly separate contact windows introduced by Yahoo back before tabs became popular.
You are technically correct. The best kind of correct.
The Chaser have always seemed somewhat critical of Howard, but making fun of APEC is like making fun of Howard's mum.
At the very least, they won't pull Chaser's before the election, and might not be able to afterwards. It looks like we're in for some interesting viewing over the next couple of months!
Remember why the Glasshouse got axed? You can't be critical of the Liberal party's ridiculous actions! Especially when [click]
What matters is what axioms you begin with. Existence or nonexistence of god could both yield consistent universes.
So, metaphysics provides no answers, and you've got to look at history for hints. Most people think that the inconsistency of major religions is proof that there can be no truth there. On the other hand, it's hard to believe that people can be THAT gullible. Maybe there are shards of fact in there, if we look close enough. Maybe the inconsistencies are in there to stop anyone with a brain from looking closer, and trying to discern truth through the millennia of lies.
Or maybe I'm wrong. It's an awkward twist to find motive for the sort of distortions of dogma that would be required to go from something believable to modern religion. Definitely worth more scrutiny, though, IMHO.
Whoops, thankyou.
Oh no, the OP is a quiche eater. I was just worried he'd screw up the indices and post questions about why it doesn't work to slashdot.
...don't seem to work very well in the case of variable wave speed at different points in the domain, which is exactly the case that I need. Look closer. Wave speed is a parameter in the DE, and all solution methods of linear DEs are local. If you treat the parameter as variable, it will be obvious what you need to do in both FEM and FDM.What numerical methods do you use, and which programs do you find best suited to the task? Well, always fit the method to the problem. As usual, FEM if you've got an odd boundary conditions, FDM otherwise. And don't forget other methods like integral transforms and greens functions, which can simplify or complicate your problem to varying degrees. Mathematica and Maple are good for a lot of things, having features for symbolic manipulation. Of course, D/C/LISP/Python/your-favourite-language-here work well enough for the actual crunching.
How do you deal with stability issues, boundary/initial values, and other pitfalls? Stability issues: The best thing you can do is prove stability. See if you can fit backwards and forwards together a-la Crank-Nicholson, and check that for stability. Or, use something nicer like Runge-Kutta in the time domain.
Boundary/Initial Values: You do what you have to, I guess. That's a lot more problem specific. If you haven't got the standard initial-time/bounded space situation, you can approximate an unbounded region. It's a lot simpler than you would think, but you need to solve it for your specific problem. Bounded-time is different, but you can then do FDM in the time domain.
Other pitfalls: Stiffness can point to a flaw in your reasoning. Scaling is worth a try. Otherwise, there are always methods to deal with your specific problem. Talk to your friendly neighborhood mathematician.
Are there different methods for electromagnetic wave problems? I think they are usually easier with analytic methods. IANA electrodynamicist, but try a few things out.
Finally, when the numbers have all been crunched, how do you visualize your hard-earned data? Matplotlib is good if you work in Python. If your employer uses Matlab/Maple/Mathematica, use those. I find Matlab awkward, and Matplotlib is similar and has most of the same features.
And if the problem is significantly complex or you need more general solution, try a Greens function.
The Wii definitely works
I think the whole "dangers of dynamically typed language" was just a brain fart by the GP. For starters, it is off-topic, in an otherwise well put together post, simply suggesting that e is not as educated on the subject as e thinks e is. Move along, nothing to see here.
Plenty of mechanisms exist today that don't require Javascript. However, it's the content provider that ultimately decides what methods get used. I don't see many providers jumping on the no-Javascript bandwagon any time soon. What it comes down to is, for the foreseeable future, you're probably going to need Javascript in these facilities.
It sure is a hack. YouTube were an example pulled from the post, I didn't really want to point the finger at them specifically. And, I guess it is clichéd to complain about web developers not designing websites to work in environments where scripting is disabled, but that's really what it comes down to: there is no getting around this in the foreseeable future, so you can't just turn it off.
Goodnight!
Animations and interactivity are always great- Mathematica, Maple, or Python + Matplotlib can be handy for this. If you have access to fluid or electrical system modelling software too, great. Otherwise, there is not a lot you can do. At the end of the day, there is only one way to learn to apply principals: a combination of reading and examining the ideas, and examples.
Some people have mentioned having the notes reproduced in PDF- I found I did much better in the university classes where notes were distributed rather than having to be copied down, because it leaves more time for meditation on the subject matter, and reduces needless duplication of work. I doubt it would work the same in high school, though.
Agreed. Isn't modern PC graphics hardware good for 500 Gigaflops? Yay for CUDA.