Recent content by wildemar

Thanks bcrowell. I've heard that analogy before, and I'm quite OK with it (NB: Hydrogen bonds are covalent, not van der Waals-like). However, my question is specifically about the transition from the color force to the nuclear force, or, in terms of particles, how the gluon-based force becomes a...

Hi all, I'm can't wrap my head around this. I get how the strong interaction bonds quarks into baryons and I get the pion exchange model for the attraction between nucleons (well sort of, I still don't understand how exchanging massive particles can result in an attractive force, but OK)...

Oops, totally forgot about this thread. First up: Thanks AEM, this was indeed what I was looking for. Thank you very much. As for books, salparadise, I really haven't read a lot. I only really know D'Inverno's book, which isn't detailed, but easy to follow. So no luck there. He certainly...

Hey, cool. Thanks. By now I've gotten so used to defining metrics via the scripts that I'm probably not going to do this a lot, but it's good to know nonetheless. :) Take care /W

Sorry, haven't found a real solution yet. But as a workaround, I just started defining the tensors as .mpl files (the same way they are stored anyway) and loading these with qload. Just look at some predefined metrics and you'll figure it out pretty quickly. best of luck, /W

Hello all :) Homework Statement I'm trying to understand the fundamentals of General Relativity, but alas, I seem to be unable to grasp the fundamentals of variational calculus. Specifically, I'd like to prove the following relation for the square root of the negated determinant of the...

*slaps forehead* Man! Thanks Patrick. That was it, of course. Gee, there it was, right before my eyes and I didn't see. You're the man now, dog! :) Really, I can not express how grateful I am. Now I can finally start doing some serious calculations again. regards, /W

Uhm, anyone? If what I'm writing is unclear, or even if you think what I do is correct, I'd really like to know. Sorry to bother you. Maybe this is more appropriate in the GR section? If so, can I move the thread?

This is driving me nuts. (I originally posted this to the coursework section, but in thinking about this, I felt that it might not be the right place (this is for a term paper, not really any ongoing coursework, so there). Hope I'm not imposing ... I feel quite embarrassed on this one, since it...

No, by "\end{subsection}" (literally). BUT. Don't even bother. Just use the \section, \subsection, etc. commands, rather than the environments (I didn't even know they existed until now). regards, /W

The advice from one of my professors rings as true as ever: I need to be more precise. I of course did what you said, not what I said i did. *sigh* OK then, thanks again.

Holy Moly, that was quick! I think they did. And part of my problem thus far was probably that I assumed that the Robertson Walker metric had to be in spherical coordinates, because of the isotropy of space (D'Inverno, whom I've used to learn GR/cosmology, used this argument for introducing...

Hello folks, this is going to be a bit longish, but please bear with me, I'm going nuts over this. For a term paper I am working through a paper on higher dimensional spacetimes by Andrew, Bolen and Middleton. You can http://arxiv.org/abs/0708.0373" . My problem/confusion is in...

First thing to note here is that LaTeX has two types of "bad messages": Errors and Warnings (you may know this). Errors mean that there is certainly something wrong and incomplete with your output. Even if you can view the output, likely some pages are missing or something. Fix those, by all...

OK, so you the most basic things you can do with the latex's own picture environment. But there are other, more advanced options. The most popular might be the the http://tug.org/PSTricks/main.cgi/", because it definitely works with pdf output (and, well, I know it better than pstricks ...)...