Re: How does a Faraday disk really work?

On Aug 2, 6:28=A0pm, "Timo A. Nieminen" <t...@[EMAIL PROTECTED]
> wrote:

> > 2. =A0Given Maxwell's equations and F =3D q E, can the forces between
w=
ires
> > carrying current be derived?
>
> No. Given these and special relativity, yes (and I've seen students
> discover that it's harder than they first thought, but educational). You
> don't need the entire Maxwell equations, all you need is Coulomb's law +
> SR.

Actually the whole issue of electromagnetic forces is a problem. It is
discussed in some detail in appendix 3 of the reference I just gave
you.  He calculates the "force" between two dielectric plates 4 ways
and then between two parallel wires 4 ways. Each gives the same VALUE
of the "force", but in each case the force is acting in a different
place. This leads to a conclusion that the action of "force" from a
field actually is only a mathematical device and does not exist in the
mechanical sense. Further investigation shows that it is actually
MOMENTUM transferred from the fields that is the essence of what
appears to be electromagnetic force.  It's all a very interesting
exposition.

Personally I try to never get involved in the on-going USENET "who is
smarter than Einstein" relativity debates.
I have my own dead horses to beat!