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Hi jcns,
I enjoyed reading your papers. I think, as I suspect does George Ellis, that the part -- which is by far the major part -- which is fully relativistic, is the part in which I would fully agree. So I will only take issue with a couple of points that question the completeness of relativity:
You quoted Feynmann: "... nature is telling us that time and space are equivalent; time becomes space; they should be measured in the same units." [Feynman's italics.] I would submit that Feynman's 'trick' was no trick at all, but rather an accurate portrayal of reality."
Doesn't that depend on what one means by "reality?" Feynmann is not trying to trick us -- he is describing a two-dimension (complex) space that is the source of an n-dimension Hilbert space. This is the space of quantum probability predictions. Hawking got imaginary time by imposing this flat complex plane on the surface of a sphere (Riemann sphere); "what happens," he asked, "when one goes north of the North Pole?" Well, of course, there is no such thing -- that singularity, the pole, is the limit of real spacetime, yet one can speak in quantum-mechanical terms, of imaginary time in that context. "Reality" is therefore inherently nonlocal in that picture, which conflicts with Einstein's relativity in which spacetime is physically real and all physics is local.
Elsewhere you write, "It is absolutely crucial to recognize here, and to point out explicitly, however, that the changes which we observe in the configuration of the universe are not caused by, and are not in any way a consequence of, the flow of time. Rather, the changes we observe (as well as those we don't observe) are the flow of time. If the configuration of the universe did not change, there would be no flow of time."
Actually, there can be a flow of time in an unchanging universe, too. A geometric flow does not necessarily change the global geometry; it only changes the local relations between points. I get what you mean -- however, in this statement you are implicitly assigning causality to the observer. A quantum mechanic will agree with you; a relativist won't.
You say, "The universe may be the ultimate example of 'what you see is what you get.'"
Maybe. It wouldn't be a relativistic universe, though. In a relativistic universe, unlike a quantum mechanical universe (if quantum mechanics were mathematically complete), there is no assignment of nonlocality to events not observed; metaphysical realism is local realism.
Few, I think, appreciate the mathematical completeness of relativity (every element of the mathematical theory corresponds to every element of the physical reality) -- so I think it's fortuitous that a whole institute (The Minkowski Institute) is now forming, and dedicated to understanding spacetime. Its esteemed founders include Ellis and Vesselin Petkov, as well as another of my favorites, David Finkelstein.
Just some things to think about.
All best,
Tom