Dear Tom,
I appreciate your readiness to take issue concerning SR. As promised I will continue to explain the reasons why SR is not convincing to me. I will do so in detail at my thread 833 because my arguments are related to my essay.
1T: "When we speak of distances between mass points increasing or decreasing, we describe a symmetry between positive and negative acceleration."
1E: Relativity of motion with constant velocity does not need acceleration. Einstein's 1905 paper did not at all mention acceleration.
2T: The twin paradox is not a paradox, true, but for different reasons than you describe.
2E: Only proponents of SR declare the twin paradox not a paradox.
3T: "The case is asymmetric, in that the traveling twin has to negatively accelerate to return to his point of origin, a condition that does not apply to the stay at home twin."
3E: While Bohm in his chapter XXX 'The "Paradox" of the twins' takes acceleration into account, he nonetheless avoids your argument. There is a simple counterargument: The growing difference in age depends on how long the journey is. The effects of accelerations don't.
4T: "Van Flandern's analysis, as I understand it, has the speed of gravity exceed the speed of light by many orders of magnitude, which I find incompatible both with a fully relativistic theory and a quantum theory. I would be satisfied to find the speed of gravity to be infinite (Mach's principle) but not limited in any other terms than the exchange of signals among bodies. This leads us to a field theory, knowing that the influence of both gravity and EM fields is infinite, in accordance with the inverse square law.
4E:It is not my business to deal with gravity. Many arguments of Van Flandern seem to show that the putatively overwhelming body of evidence for SR is in so far invalid as there are alternative, often simpler and more plausible interpretations. Having found the origin of Lorentz factor in a speculative application of an old mechanical model of atoms, I wonder why not even Van Flandern abandoned it, the more because he was fully aware that there is no length contraction and time dilution in reality.
Before my final judgment I will read Richard Haskell 2003 Special Relativity and Maxwell's Equations.
Regards,
Eckard