sci.physics.electromag

On Fri, 7 Sep 2007, rge11x wrote:

> On Sep 6, 6:38 pm, Timo Nieminen wrote:
>> On Thu, 6 Sep 2007, rge11x wrote:
>
> Thank you for the very thoughtful and detailed answer.
>
>> If the ether were an ideal classical continuous medium, it would support
>> vibrations at all frequencies. In thermal equilibrium, there would an
>> infinite amount of energy in the high frequencies. The ether would have an
>> infinite heat capacity, and would be at essentially absolute zero. Matter
>> in contact with the ether - basically all matter - would very rapidly cool
>> down. This is, basically, the ultraviolet catastrophe in black-body
>> radiation.
>
> Why do we have to assume that the "ether" is in thermal equilibrium
> with anything? Since everything were to move "in it", if it existed,
> how could it be in any state but in nonequilibrium? Seems to me that
> we postulate nonphysical properties to a hypothetical thing and then
> decide that it cannot exist because these properties are nonphysical.

If electromagnetic effects are due to ether, then matter interacts with
ether, especially electrically charged matter. One is faced with either
extending thermodynamics to include ether, or to exclude ether from
thermodynamics. Given that hot bodies glow, the latter seems unlikely.

This also means that thermodynamics is the death of classical
electrodynamics (or of classical matter, but one way or another, classical
physics is defunct), but that's quantum mechanics for you.

Assume there is an ether. Then it must have properties. We can assume that
the properties are "obvious", ., based on common sense or common
experience, or we can assume the properties are bizarre. Much more
comfortable to assume the former. Alas, it doesn't seem to work.
Therefore, why assume an ether?

Yes, one could construct an ether with whatever special properties are
required to match experiment (expect perhaps a local ether matching
quantum mechanics, but one might manage a non-local ether). It's not that
one needs "nonphysical" properties, but that one needs properties even
stranger than conventional theory. Surely, there are an infinitude of
theories that can explain things, but multiplication of theories that
cannot be experimentally tested is not science.

All one needs to do to retain an ether is to construct a theory of ether
that deliver electromagnetism and quantum mechanics and relativity. Assume
A, B, C in order to get X, Y, Z. Why not just assume the experimentally
accessible X, Y, Z to start with? Perhaps this is merely the opinion
resulting from working in applied physics, but I think that Ockham's razor
is a useful tool (not infallible, not universal, but certainly useful).

> I was surprised to hear that the ultraviolet catastrophe/
> thermodynamics was the death blow to the ether. It was surprising to
> me because there is something non-EM-ish about them; I have completely
> bought into the idea that the apparent asymmetry in the moving frames
> Einstein was talking about killed it.

Well, that's one step beyond the usual "Michelson and Morley killed the
ether" one sees in many textbooks. Panofsky and Philips is exceptional in
giving a very good account of experiment.

You might like some of Giora Hon's stuff on symmetry in physics. There was
a nice paper on symmetry in SR. Google or google scholar should find, but
if you can't, email me.

--
Timo Nieminen - Home page: http://www. /people/nieminen/
E-prints: /view/person/Nieminen,_Timo_A..html
Shrine to Spirits: /timo_nieminen/