sci.physics.electromag

On Mar 7, 7:17 pm, "Timo A. Nieminen" wrote:

> Part the Second
> ===============
> The retardation of electromagnetic effects presents a direct challenge to
> the view of electromagnetism as solely an interaction between charges and
> currents, with fields merely as a mathematical auxiliary. This is
> especially the case for radiation.

This is exactly correct! This is what Jefimenko has done in his
approach and has taken quite a bit of flack for. One problem is that
a huge amount of problems have been solved using Maxwells equations
NOT taking retardation into account. People have become so familiar
with these that they start to assume that these solutions are absolute
and correct. As you point out, they are not except in certain special
cases. And this "approximation" thing gets far worse. In practical
calculations of electromagnetics it's not only common to ignore
retardation but to ignore a whole host of other problems as well. You
do complex caculations only to find oddball results that are summarily
tossed aside as "non-physical solutions". What in hell is that? Does
the theory work or does it not? Obviously the "problem" is that we
are using a model to represent reality and the model is not an exact
fit. OK. Fine. So long as you KNOW you are doing that. You have
practical solutions available to all manner of practical problems.
But the trouble starts in PHILOSOPHY! This is when one starts to
regard the MODEL as "reality" itself. There is FAR too much of this
kind of dogma in physics today! And THAT is my point.

> While fields introduce some problems into physics, I believe they resolve
> more than they introduce. The mathematical convenience is immense. Whether
> they are "real" or not, they are certainly useful. The only stance that is
> certain to be properly aligned with reality is agnosticism wrt the reality
> of fields or otherwise. However, I'd say that, on balance, it's reasonable
> to assume that fields exist. This opinion may well be coloured by the
> practical engineering usefulness of assuming that they exist.

Wow. Major exposition!

Do you see what you've just said here? You've said in essence that
it's OK to assume fields exist because that mathematics gives me lots
of practical answers to questions I have and the answers seem
reasonably close to what I'm measuring! You are saying that physics
(science) is a religion where the important thing is how you feel
rather than what is true. If believing in fields gives you comfort
then, who is to say that you shouldn't do it? Well, I say that
philosophers say you shouldn't do it. They say that one has to be
careful in your definitions of what is reality and what is merely a
model mimicking reality. And to them that difference is fundamental.
In religion the difference doesn't matter. But science is supposed to
be tested constantly against observation and if you don't do that then
it ain't science anymore.