"Jesse Mazer" wrote in message
...

Of course, before Einstein physicists didn't think Maxwell's laws
would be correct in every observer's reference frame--they thought
they would only hold exactly in the rest frame of the aether. They
would have believed that to state the laws of electromagnetism in a
way that would hold in all frames, you'd have to replace every x in
Maxwell's laws with (x - v*t), where v represents the observer's
velocity relative to the rest frame of the aether...any derivatives of
x would have to be replaced in the same way, like replacing dx/dt with
(dx/dt - v). This would give a new set of electromagnetic laws which
would be Galilei-invariant, and which would reduce to Maxwell's laws
in the case where v=0.

But a prediction of this Galilei-invariant analogue of Maxwell's laws
would be that for an observer in motion relative to the aether, light
will be observed to move at different speeds in different directions,
relative to himself. Unfortunately this was not supported by the
Michelson-Morley experiment.

The speed of light in diamond, water, air, any transparent medium is
constant with respect to the medium. MMX fails to support aether.
In MMX, the medium is air. It is as simple as that.


Androcles proposes to explain this negative result with the suggestion
that the velocity of light depends on the velocity of the source,
Since source, medium and detector are all relatively at rest, MMX
disposes of the aether only.
1) speed of light relative to source.
2) speed of light relative to medium.
3) speed of light relative to detector.


MMX satisfies all three.
SR fails to satisfy MMX, however.

but this would be false according to both Maxwell's laws *and* the
modified Galilei-invariant analogue of Maxwell's laws (which says that
light waves, like sound waves, always travel at the same speed in the
rest frame of the aether/air,

Forget aether, it doesn't exist. Air does, though. So does water.
A stick passing through the air-water interface appears bent.
That is empirical evidence that the speed of light is medium dependent.



regardless of the velocity of their source).

Source dependency only applies in the absence of a medium. There is
no aether.


So unless he can find a theory that gives correct predictions for all
the various experiments in classical electromagnetism, and yet does
not have the feature that the velocity of light is independent of the
source velocity, then his ideas wouldn't even have seemed plausible to
a physicist in a time before the theory of relativity had been
published (but after the Michelson-Morley experiment had been done).

Nobody has a computer then. Today we can calculate what the result
would be if a bullet stream from a moving machine gun moving in an
elliptical
orbit that obeyed Kepler's laws were to arrive at any distance.
The intensity of arriving bullets (grey line) looks like this.


http://www.androc1es.pwp.blueyonder....r/V1493Aql.JPG

If you examine the image closely, you'll see a crossover where the
faster bullets
has caught up with and passed the slower bullets.
That is a simple distance / time plot, distance vertical and time
horizontal.
What you would see is a sudden increase in the rate of arrival of
bullets,
then a second maximum, eventually tailing off.
A star in elliptical orbit would do the same thing.
Androcles.