Robin van Spaandonk wrote:
In reply to Stephen A. Lawrence's message of Mon, 09 Jun 2008 16:51:17 -0400:
Hi,
[snip]
Aether theory is predicated on the notion that there is some kind of
aether which carries some kind of vibrations; as such that's a sort of
fuzzy explanation (though the details are pretty wild if you stop and
think about what sort of material aether must be, keeping in mind the
obvious fact that planets and stars plow through the aether with no
impediment to their motion, along with the fact that vibrations
traveling in any known medium go faster as the medium becomes stiffer
and slower as the medium becomes floppier -- and vibrations in the
aether travel really wicked fast, so it must be really wicked stiff,
which makes those planets cruising through the middle of it all the
harder to understand).
Perhaps it becomes easier to accept, if it is not a matter of ploughing
*through* the medium. Consider how a wave passes through water. The energy of
the wave is passed from molecule to molecule, but the molecules themselves don't
actually go very far. Maybe the aether works the same way. Particles (e.g.
electrons) are then *patterns* in the aether. The pattern can move, simply
through the transfer of energy, without the aether itself moving.
But then it seems like this would lead to an issue with "aether
dragging", doesn't it? Classical aether theories can't be reconciled
with the results of the Fizeau, Michelson-Morley, and Sagnac experiments
unless there is partial or complete "dragging" of the aether along with
the Earth. If the Earth itself is just a pattern traveling through the
aether that doesn't seem like a very obvious thing to have happen.
Alternatively one could assume the Earth is a traveling pattern in a
Lorentz aether, which avoids the need for dragging, but the Lorentz
ether theory loses a lot of the pleasingly "sensible" feel of classical
aether. It leads to the same mathematical model as special relativity,
which implies, in particular, that, while there is a distinguished
"aether rest frame" in Lorentz ether theory, it cannot be detected in
any way. There is no way at all to tell how fast you're moving relative
to the aether, because all experiments produce the same results
regardless of your absolute velocity; consequently you can't tell if
you're stationary with respect to the aether or not. In fact, in
so-called LET, the aether cannot be detected in any way; the theory is,
in a word, indistinguishable from special relativity. This leaves one
in a somewhat uncomfortable position, which is that of taking the
existence of the central object in the theory entirely on faith.
*If* the aether itself is incompressible, then compression waves travel at
infinite velocity, however transverse waves are probably limited to the velocity
of light.
Regards,
Robin van Spaandonk
The shrub is a plant.
