sci.physics.electromag

On Thu, 6 Sep 2007, rge11x wrote:

> [...]
> > Sure. The ether persisted long after special relativity was around.
> > SR basically doesn't falsify the ether, although it makes it unnecessary.
> > Compare with the way that Maxwell's equations and their success made his
> > mechanical models of the ether equally unnecessary. Thermodynamics was the
> > real ether-killing theory.
>
> What did you mean by this comment: "Thermodynamics was the
> real ether-killing theory."? Could you expand on this?

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.

There are at least three solutions to this problem. One is that, since we
have a set of equations describing electromagnetism, to look for another
explanation for why these equations are what they are. (And Coulomb's law
+ SR is a nice foundation for electromagnetism.)

Another is to postulate that the ether has unknown properties - that it's
basically a magical substance. I don't see how this is any better than
assuming the equations of electromagnetism are what they are, and not
looking for any further explanation. Worse even, because the laws of
electromagnetism are deduced from experiment. Unless whatever ether is
suggested is experimentally accessible through something other than
electromagnetism, there would be no way of verifying the claims.

Finally, we can assume an "atomic" ether, composed of discrete particles.
Alas, a discrete ideal gas ether doesn't do transverse waves. OK, the
ether atoms need to interact at a distance. Why would it be acceptable
that we need an ether to explain interaction of electric charges at a
distance, but don't need to explain why ether atoms can interact at a
distance? Oops! Better introduce a sub-ether. Same thermodynamic problems,
so there had better be a sub-sub-ether. Etc.

I think that the first of the three options is the soundest, and the best
in terms of theoretical and logical economy.

Some reading:

J. H. Jeans
"On the application of statistical mechanics to the general
dynamics of matter and ether"
Proceedings of the Royal Society of London A 76, 296-311 (1905)

J. H. Jeans
"The present position of the radiation problem"
Proceedings of the Physical Society 35, 222-224 (1922)

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