A

discussion of relativity should begin with the Michaelson-Morley 'experiment'.
Example:
If you have a metal rod and suspect that it will shrink in the presence of cold air, you might place it in a refrigerator, take it out after a time and see if it is smaller. Of course, you would measure it with a ruler before and after the 'interaction' (cooling) and check for a difference.
Let's say that the ruler is made out of the same material as the metal rod and is the same size. Then we can put one rod next to the other and, seeing that they are both of equal length, throw both of them into the refrigerator. After they have cooled we take them out and see if they are the same. Right ??

Is this an experiment ??

No. But this is what Michelson-Morley did.
A proper experiment requires a state A which becomes state B by way of the interaction of interest. (See Determinism and Causality)
A and B are 'measured' against a standard (ruler or other device appropriate to the experiment) which is not functionally attached to the experiment. This is the critical mistake of the M&M experiment. They measured a length. The standard by which that length change was to be measured was the slab of concrete floating in mercury on which the experiment rested. Since it was "in the wind" nothing but a null result could have been obtained in principle. (Actually, if the ether wind flowed differently through air than through concrete they would have gotten a 'result' , albeit spurious. But their experimental intent shows that they believed that the ether flowed without resistance through anything whatsoever.)

Historically, it did not matter because the result led to the right theory of nature (relativity). One thing should be corrected however. Because the M&M experiment was not logically valid, the Lorentz-Fitzgerald contraction is not "ad hoc". It is, in fact, born of clear logical necessity.

Relativistic invariance can be accomodated in the presence of an absolute reference frame.
In this way:

'A' proceeds at some finite velocity through the absolute reference frame.
B and C leave A and travel to equidistant points (as measured by A) then return to A in equal times. Clearly, B's clock slows on the outward bound trip in the direction of A's proposed absolute motion while C's clock speeds up in the opposite direction. C reaches the turnaround point before B (absolutely) but takes longer on the return trip so that B and C return to A simultaneously. B and C always appear the same (to A) throughout the trip.
Since A cannot detect his own motion by reference to a standard carried with him (or the logical equivalent), there is no contradiction with special relativity (the standard theory) which only states that an absolute reference cannot be "detected" by such means.

An absolute standard can be detected only by reference to the 'context' in which motion takes place, i.e. the backdrop of stars or the 'cosmic' background radiation. Here 'absolute' is defined as something two observers could agree upon unambiguously as an absolute standard. And this standard can be pinned down, in theory, to accuracies on the order of Compton wavelengths.

The observable results of relativistic velocity are consistent with the present theory by the following mechanism.

Translational movement of a 'particle' through the continuum will result in a contraction of the particle in the direction of motion.
The reaction velocity (v) is given by:

2R/v = v/(4pi R^2) or 2R/v = v/x and v = (2Rx)^1/2 where x = number of positional fields encountered per unit time (4pi R^2). See #11

If x were altered by a factor 'z', the resultant confinement (D) would be altered by a factor z^1/2.

D = v/x = [(2Rzx)^1/2] / [x] = [z^1/2] [(2R/x)^1/2]

= [z^1/2] [(2R / 4pi R^2)^1/2] = [z^1/2] [1 / (2piR)^1/2 ]

Such a change would occur when x is 'reapportioned' by factors of (1+u) , (1-u) and (1) where u is any absolute velocity less than unit velocity. That is, the particle incounters 1+u more fields from the front per unit time and 1-u from the back while the sides remain constant (in the direction of absolute velocity).

The total number of fields encountered per unit time must remain constant at 4pi R^2 ( for all velocities less than c ). Therefore, only the reaction velocity in the direction of motion is affected which in turn determines confinement.

z^1/2 = { [(1+u)(1-u)(1)] }^1/2 = (1-u^2)^1/2 which is the standard coefficient of relativistic contraction.