Hi Eckard
You know that assumptions are discarded based on experimental evidence. It is evident that no experiment can rule out the PRS, but quite the contrary, some experiments can suggest its reality. Of course, one can build a theoretical framework in which the PRS does not figure. Like I said, the physical interpretation of observations depends to a high degree on the theoretical frame. So if you do not share their views then the issue may become only a matter of taste, prejudice or parsimony [See my questions in reply to Jason below, I kindly ask you to answer them as well].
Christov's theory, for instance, reproduces present experimental observations, unifies electrodynamics, gravitation and quantum mechanics, and in doing so, his theory removes the wave-particle duality and the probabilistic interpretation of the wave function. It also sheds light on the dark matter and dark energy problems. Besides all of this, the theory makes a new modest prediction. This same state of things happened with Maxwell theory until 20 years later, Heinrich Hertz proved Maxwell was right.
You wrote: How about restoring simultaneity as does Phipps?
I just have to say: simultaneity is related to clock synchronization and clock synchronization is related to the one-way speed of light and the one-eay speed of light is related to clock synchronization. Experimentally this is a dead end. If this is true, there is no point of discussion. I asked before if you or James know about any reference where the one-way speed of light a la Roemer has been measured, but none of you has replied. The unambiguous knowledge of the one-way speed of light is not only crucial to solve the issue of simultaneity but others as well. So, do you have anything to contribute for this cause? Daryl has something else to say with respect to simultaneity.
You say: So far I cannot see in what Einstein was wrong when he considered his PR based on his denial of a PSR.
From the experimental viewpoint the rejection of the PRS is not justified. Experiments carried out in the PRS will lead to the same physical laws as in any other frame of reference. So, if a theoretician acknowledges that experiments define the shape of the physical laws, the theoretician contradicts himself by denying the PRS. Einstein thought that all systems of reference are equally valid for the description of physical phenomena and assuming a PRS will imply making a special distinction in his theory, this was for him a theoretical asymmetry that for a theoretician was intolerable. Unfortunately, he believed that the word RELATIVE demanded denying absolute motion. This is not the case, it only means "relative to", so the assumption of the PRS is legitimate.
Israel