Recent content by chickenz

Hmmm... This sounds like it could work. It's more mathematical than I would have hoped, but parametrizing worldlines is something that I ought to try, and maybe I'll gain some insight from it. Thanks for your help.

Hmm... I'm not sure I buy that, but thanks for trying. Maybe it's not worthwhile, from a physics standpoint, to think about what [H,H] means.

Yes, that's the type of explanation that I was looking for. Unfortunately, I don't believe your argument. Let O be the origin of our coordinate system, and let A be the event where we measure the force on the test charge. O and A are simultaneous in the rest frame of the central charge. 1...

Thanks! So, now my question is more of a physics one: Suppose we have a quantum mechanical Hilbert Space H. Is there an interpretation to the set H/[H,H]? (other than the fact that it's the smallest quotient of H that is Abelian - I'm looking for a physics interpretation here)

Ooo. I bow before your genius. But of course, gold still has some awesome properties that make it a useful material. But you could no longer justify the $1500 per ounce price tag.

Like others in this forum, I don't think it's possible. However, even if it were, and supposing the process was somehow inexpensive, then why? Gold's value comes from the fact that it's shiny, pretty, and rare. Take away it's rarity by mass producing it, and you've got a whole bunch of...

If you are looking for a mathematical answer based off Lagrangian/Hamiltonian mechanics, here you go: http://galileo.phys.virginia.edu/classes/752.mf1i.spring03/ParticleMagneticField.htm

Perhaps someone can tell the original poster the conditions for which the signal velocity (which must be less than c) is approximately equal to the phase velocity or to the group velocity or to neither. I believe that, most of the time, if there is a fairly well-defined envelope for a wave...

I'm afraid Coulomb's Law is wrong in the context of moving charges.

The commutator for group theory is [X,Y]=X^{-1}Y^{-1}XY whereas the quantum commutator is [X,Y]=XY-YX . At first glance, the two commutators seem to be totally unrelated because the quantum commutator speaks of two binary operations whereas group theory has one binary operation. However...

Ah. I think my question is still being misinterpreted. Here's my question, rephrased again: The electric field of a uniformly moving charge points at the charge's present location, not to the retarded position. Is this obvious from Maxwell's Equations or Special Relativity? (And by...

Hi. I'm in condensed matter experiment, and I was wondering whether employers (in academia or industry) would look less favorably on hiring people whose BA institution and PhD institution are the same. I've heard different answers from different people about this question. Some say that...

Oh, that wasn't what I was asking about. Sorry. Let me rephrase the question: Is the fact that the electric field of a moving charge points to the charge's current location immediately obvious from fundamental principles, or does it just follow from the math?

The electric field of a charge moving with uniform velocity points towards the charge's present location. You can either get that from a whole lotta math on the vector and scalar potentials. Or more easily from special relativity. Is there a quick, minimally mathematical, and intuitive...