Speed of Light Experiments Revisited

Classic (and incredibly precise) experiments on the speed of light show that the orientation of the light bouncing back and forth does not affect the time needed for the round-trip. This has been taken as proof that the speed of light in an inertial reference frame is constant. The Kennedy-Thorndike experiment with differing path lengths showed that the FitzGerald-Lorentz contraction, which calls for all objects to physically contract along the line of motion, would be false unless the predicted time dilation is correct. The kinetic interpretation was considered ad hoc until Einstein described that physical contraction as kinematic, due to changes in space and time.

The mnp Model suggests that matter moves only by dilating its own measurement of time and compressing itself along the direction of movement, that space can be seen as a uniformly static/expanding/contracting Euclidean stage on which movement takes place. Light, fields, the rotating constituents of matter, and the random constituents of the vacuum potential all move at the speed of light in the one and only reference frame. How could that possibly be consistent with the round-trip experiments done with such great precision?

At rest, one might expect light bouncing between mirrors L distance to take 2L/c. If there is only one reference frame, in a frame moving at v, light moving between mirrors perpendicular to v would take 2L/(c*sqrt(1-v^2/c^2)) to make the trip due to a longer path. Light moving parallel to v would take 2L/(c*(1-v^2/c^2) ) to make the round-trip due to a longer path parallel to movement and a shorter return path. The difference in round-trip times is a factor of sqrt(1-v^2/c^2).. But all the experiments done in the last 120 years show light taking the same time to make the trip at all orientations. Pause for dirge music on behalf of the single reference frame.

Look a little closer. If the clocks in the moving frame all move slower by sqrt(1-v^2/c^2), the perpendicular to travel case shows the round-trip time as 2L/c. In the parallel to travel case, the clocks are still slow. But the length L is measured with rulers that are shorter parallel to travel in the moving frame as well. So the moving frame sees the round-trip time parallel to motion as 2L/c as well. So the gloriously precise round-trip experiments have made physics and the speed of light in an inertial frame safe for two options: one theory (Special Relativity) and one type of diametrically different model (mnp Model or cousins, with a single reference frame).


The difference in the travel time forward and backward has not been fully examined, as far as this amateur can discover. That should not be a surprise or a criticism. The apparent galactic motion compared to the Cosmic Background Radiation is “only” 627+-22 km/s, or .002c. The time dilation would be only 2*10-6. True one way experiments might be diffraction of a known extra-terrestrial source such as the Cosmic Background Radiation at different orientations. Care with interpreting the width of the slit, the distance to the receiver, wavelengths, and the time over which photons are counted is needed. If the source is terrestrial, care with mirrors (and smoke) will be needed.

So, admitting that 100 years of tradition has had glorious success, the author agrees with the professional physicist's judgment. That's nutty. Really nutty.

Yet kernels remain to be found. Thought experiments like the mnp Model might even have some.