This is part 2
Of course one can argue as you did. If I cannot determine whether I am at rest or in motion it is meaningless to say ''what is my absolute position?''. Above all, this is just a technical problem but this does not imply that the PSR does not exist. In my previous post, I asked you take a look at my reference 17. There I explain, for instance, that the one-way speed of light cannot be experimentally determined and it has never been measured. So, if I follow your same line of reasoning I could argue that the second postulate of special relativity is meaningless because it can never be experimentally verified. Again the determination of the one-way speed of light is a technical problem but the fact that it cannot be measured does not imply that (in an isotropic and homogenous space) the speed of light is not isotropic. In this same article I made the calculation of the measurement of the one-way speed of light. I showed that it is necessary, if one wishes to be coherent, to introduce a special system of reference (isotropic system) where it is assumed that the one-way speed of light is isotropic. Then, if an observer in the isotropic system judges the operation of measuring the speed of light of another observer in a system moving at constant speed v relative to the isotropic system, he will find that the observer in motion should measure a one-way speed of light dependent of v, i.e., anisotropic. But since the observer in motion can only measure round trip speeds, the average speed he will find is c, in agreement with actual experimental observations. So the observer in motion thinks that in his system the speed of light is also isotropic. Hence again, from the point of view of the observer in motion, he assumes that his system is the isotropic system and concludes that in the initial isotropic system the one-way speed of light is anisotropic although the two-way speed of light remains constant. Again we have another paradox since no observer can decide which system is the isotropic system, both are isotropic and both are anisotropic. If you are really interested in this problem you should take a look at my reference and references there in. There you will familiarize with the perplexities of special relativity. And so, probably, you will understand why one has to reintroduce the PSR; this is one way to eliminate all these antinomies.
You: I don´t quietly understand that. In relativity, there is only one space-time manifold, but different basis in which we may write 4-vector an so on. So yes, time dilatation DOES occur (see the experiment where clocks in the earth and in an airplane measure different intervals for a round trip on earth), length contraction DOES occur.
My above comments are related to this paragraph. What I can figure out is that you are confusing the experimental implications of the theory (i.e., the predictions of the theory) with the internal consistency of the theory. From the experimental point of view relativistic effects are real, they do occur (and they are real because the PSR must exist) but strictly speaking and in theoretical terms they are apparent. They are apparent because special relativity denies the PSR and therefore there is no real motion and no real effects (or absolute as you understand).
Israel