magnetic potential

matter ? Not needed.

It is all contained in Maxwells equations.

Time for you to study up!

Usually there is more than one way to describe a theory. Take wave mechanics and matrix mechanics as one example, It was Born who showed the equivalency. Then there is thermodynamics and statistical mechanics.

In the case of vector potential, when you formulate the hamiltonian form, derivatives of the hamiltonian with respect to a p or q that give zero indicate a conservation law.

Bill

Please advise as to what rho is in,

div E = rho

It is charge density. Please tell us a way to get charge density without charged matter.

Best,

Fred Diether Co-moderator sci.physics.foundations

Benj, thanks for quoting Feynman, chapter and verse. My take is not that Feynman was saying that the vector potential is more fundamental. But that you need to remember both the fields and potentials. Sometimes one view is more useful than the other. Both are correct. Which is more =91fundamental=92 is =91dealers choice=92.

George H.

Actually George I didn't quote Feynman chapter and verse, I only gave a reference. However now I am going to do that.

"...the vector potential A,,, appears to give the most direct description of physics. In the general theory of quantum mechanics, one takes the vector and scalar potentials as fundamental quantities in a set of equations to replace the Maxwell equations: E and B are slowly disappearing from the modern expression of physical laws: They are slowly being replace by A and (phi)."

I think that sometimes it's better to actually read what someone said rather than just have a "take" on it.

You don't know this, and nobody's "proved" it yet, but electrons are the easiest way to get charge density without charged matter. Electrons are not just "nothing", they are "less than nothing"! [aether vortexes]

LOL! Last time I checked my particle physics books, electrons are considered to be matter regardless of what they might be. What's the charge density of a single electron?

Best,

Fred Diether Co-moderator sci.physics.foundations

With what momentum? :-)

Tim

it is density of charge, not matter, matter is not needed at all.

No matter is needed for EM waves to propagate, and that is what Maxwell's equations describe.

LOL!

Hmm... What the heck does div E = rho describe then? We all hope you aren't being serious. Oh, now I see that this thread is crossposted to sci.physics. Guess it is time to leave the looney bin. ;-)

Best,

Fred Diether Co-moderator sci.physics.foundations

I hope you realize that this statement makes no sense at all. I guess I'll "consider" you to be a dog no matter what you might actually be?

You are the one making the insane statements here! It seems to me that div E =3D rho describes a relationship between an electric field and charge. I really don't see "matter" anywhere in that equation, do you?

Woof! It was a question; not a statement. Depends on exactly how you might define an electron. Of course in QED it makes no sense. But in another sense we could approximate it to be electronic charge divided by electron compton wavelength over 2pi cubed.

e/(L_C/2pi)^3

for you can't localize an electron to a space much smaller than that without creating virtual pairs.

Charge density; not charge. Again, one more time... please tell us how to get charge density without matter. It can't be done.

Best,

Fred Diether Co-moderator sci.physics.foundations

Zero.

Best,

Fred Diether Co-moderator sci.physics.foundations

Then lambda --> infinity and rho --> 0.

Tim

..

It's not very encouraging that you're supposed to be a moderator at sci.physics.foundations that's supposed to encourage discussion, even if people are wrong.

you

What is 'matter' Fred? What is something that is unique to only it?

Sheeeeesh, where did you guys learn classical electrodynamics from? Maxwell's equations describe the whole enchilada of classical EM. Much more than just EM radiation. Check back in the thread; Tom started the belittle crap first. And his first statements were totally wrong. Without charged matter, there is no classical EM. And also nothing to even start EM radiation. J = rho = 0 is a man-made abstract approximation where you are far from the sources.

Well, someone has to make sure the newbies don't get false information that seems to propagate greatly on the unmoderated groups. There are different techniques for encouraging discussion on different groups. You responded, didn't you?

Best,

Fred Diether Co-moderator sci.physics.foundations