On Jun 28, 2:57=A0pm, blackhead <larryhar...@[EMAIL PROTECTED]
> wrote:
> There seems to be quite a few people in this newsgroup who, when they
> can, keep bringing up the subject of E and B not causing one another,
> contrary to what is outlined in most text books.
> I don't see any advantages to using Jefimenko's over those of Lienard-
> Wiechert and would be interested in your views.
What is this? A "contest" to determine who has the "best" equations?
Hey, they are equations! That means NONE are "best"!
The point is that when you start talking about equations (all of which
are derived from the same basic sources) they basically are "best"
when they provide the easiest answer to the particular problems you
are trying to deal with. Maxwell's equations maybe "wrong" in that
they are not causal, but on the other hand they have nevertheless
provided a huge library of practical EM answers that are reasonably
accurate. Jefimenko on the other hand deals with causality and
"retarded" potentials which are obviously the way the world works but
adds a level of complexity that is usually ignored when seeking
practical answers...UNLESS causality plays a crucial role in the
problems you are dealing with. The L-W potential approach has often in
the past been regarded as a mere mathematical trick, but there is more
to it than that. First off they do correctly assign causality for
retarded potentials (Jefimenko talks quite a bit about this). And even
more im****tant, it appears the quantities like the vector magnetic
potential are more "fundamental" than the EM fields. The Aharonov-Bohm
solenoid effect indicates the more fundamental nature of A over B. But
on the other hand ALL these equations are "classical" and (even L-W)
quickly fail at the quantum level.
The bottom line is that none of these equations is "best" and each are
useful for certain problems and understandings.
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