My Michelson-Morley Thread (http://www.sciforums.com/showthread.php?s=&threadid=18515) made me think of this.

I would like feedback from relativists and "crackpots" as well.

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The red shift of stars traveling away from us is caused by either:

The Doppler Effect.
or
Actual frequency change due to Time Dilation and Length Contraction (Relativity).

Correct?

The way I see it, it stands to reason that:

If red shift is caused by relativistic effects:
The speed of light stays constant.
Frequency (wave length) decreases.
Therefore wave height must increase, correct?

If it is caused by the Doppler Effect:
The speed of light does NOT stay constant.
Frequency decreases.
Therefore wave height must stay constant, correct?

Here's the experiment:

Two spacecraft.
One with a laser.
One with a receptor capable of measuring the frequency and wave height.
The two spacecraft start stationary (relative to each other).
The laser is constantly on, the receptor is constantly measuring.
The two ships accelerate away from each other at very high speeds.
They stop (continuing to transmit and measure respectively).
They then fly back toward eachother.
Observe the measurments.

As they accelerated away from each other, there should have been a red shift in the laser beam frequency (however slight).
As they accelerated toward each other, there should have been a blue shift in the laser beam frequency (however slight).

If the wave height stays constant, c is not constant.
If the wave height does NOT stay constant c is constant.

What do you think?
Is my logic wrong?
Would this be conclusive?

Now I just need to get my hands on a multi-million dollar budget, and I am set.;)

one_raven,

Frequency is related to the wavelength and speed of a wave. Wavelength is related to the frequency and the speed of a wave.

Wave height is independent of the frequency, wavelength, or the speed of a wave. Wave height is just the "strength" of a wave.

C = frequency times wavelength
C is constant
Wavelength of red light is 6.4 X 10^-7 meters
Wavelenght of blue light is 4.5 X 10^-7 meters

No amplitude is implied here.
Doppler effects are quite compatible with constant C.

Also, the Red-shift is due to a combination of both Lorentz transformations and Doppler effect.

International Journal of Modern Physics A, Vol. 17, No. 20 (2002) 2777
© World Scientific Publishing Company
doi:10.1142/S0217751X02012041






NON-MINIMAL COUPLING, VARIABLE SPEED OF LIGHT AND COSMOLOGY

P. TEYSSANDIER
Département Systèmes de Référence Temps-Espace, CNRS/UMR-8630, Observatoire de Paris, 61 avenue de l'Observatoire, 75014 Paris, France

Presently, there exists some renewed interest in time varying speed of light theories as possible solutions of the major cosmological problems1. It is often believed that the local Lorentzian invariance is broken if the speed of light in a vacuum is not a constant.

We point out that this belief is not necessarily founded and that a variable speed of light is perfectly consistent with general relativity under the assumption of non-minimal coupling between electromagnetism and curvature.

Two kinds of arguments may be invoked in favour of such an assumption.

First, a theorem due to Horndeski2 shows that in a four-dimensional space-time the Einstein-Maxwell field equations are not the only second-order vector potential field equations which stem from a Lagrangian scalar density, are consistent with the charge conservation and reduce to Maxwell's equations in a flat space-time (see also3).

Second, according to QED4,5, vacuum polarization induces tidal gravitational effects which imply that photons propagating in a curved space-time have velocities exceeding the value of the "Lorentzian structural constant" c.

The modified electromagnetic field equations given by Horndeski2 are studied here in the geometrical optics limit. Considering the case of Friedmann-Robertson-Walker cosmological models, we find the value of the speed of light as a function of the energetic content of the universe.

We deduce from this result a new equation of state for a photon gas and we discuss the consequences of this equation on the evolution of the scale factor during the radiation-dominated era.

The relativistic Doppler shift formula takes into account both motion and time-dilation effects in determining the frequency shift of light.