Recent content by Meir Achuz

Thanks for your interest, but I guess we are at an impasse. The quote was something like, “with all the new math being applied to my theory, I hardly understand it any more myself.”

I apologize. I shouldn't have used that word in a technical discussion thread. The point was to show by the insert where taking 'self energy' too seriously can lead.

It was a joke, but read the insert. I appreciate that you have expended time and knowledge on my post, which I had thought was straightforward. I certainly didn't mean to bring Einstein into it. We have some agreement, but I will comment on some things: 1. You wrote,"So in principle, we can...

Of course, I mistyped. It should have been, it IS there by absence. I did write, "This PDF shows that a point charge in classical electromagnetism has no 'self energy'." That's because there is no self energy term in the sum of charges. Thank you for pointing it out. Since the continuous...

This is getting silly. Neither of us will be convinced, but you keep putting up half truths, half wrong. I will try again. You neglect what you don't want. Jackson's equations 1.47, 1.48, 1.49, 1..50 clearly show there is no i=j term. For some reason, he says it in words for Eq,. (.51). You...

Don't ignore the footnote, which I have attached. Jackson points out that infinitesimal charge is mathematical and NOT PHYSICALLY POSSIBLE, The point here is that to define E, even a small charge can polarize the source of E, making the force equation bilinear. It is completely different for...

I thought you would recognize Griffiths. Actually, the shoe is on the other foot. Can you cite a textbook reference that justifies and agrees for an electron in the case where its charge is infinitesimal??

"Chapter2 Electrostatics so,ifyouhavesetthereferencepointatinfinity, W=QV(r)." You added the word "infinitesimal". "W= 1/ 8π\\epsilon_0 sum n i=1 n j=i qiqj/rij (2.41) (wemuststillavoidi=j,ofcourse)."

This PDF shows that a point charge in classical electromagnetism has no 'self energy'.

What a weird response

Reading this thread, I see why students always get a third law question wrong.

How could there be 81 posts on this?

Anything below Griffiths would be about QM, but not QM. That's why they are easier.

The confusion is due to SI units where B and H do have a complicated connection. In Gaussian units, H is just B-4\pi M, where M is magnetic polarization of matter.

This image may help. The brother on Earth follows the vertical line. The traveling brother moves out the x-axis, and then returns. On a map, he would have traveled further. But, in space time, s^2=t^2-x^2, so he has traveled a shorter space-time 'distance'.