Space-time is NOT 2-D, It is 4-D (or, if you include the little curly dimensions beloved of string theorists, 10- or 11-D). Space-time diagrams are usually 2-D (because they are printed on 2-D paper), but only because 2 of the spatial dimensions are suppressed (=ignored).
This isn't an answer to your question, but just a comment on a couple of the things you said in your original post.
As I understand it, galaxies that are further apart than a certain distance ARE separating at a rate greater than the speed of light: this is possible because the galaxies...
No, time dilation is not due to differences in the rate of biological/chemical/physical processes in different reference frames - one of Special Relativity's raison d'etre is to make sure that these processes are always the same in any inertial frames. Time dilation (and, in fact, Lorentz...
This sounds like something I was playing with (mentally). As I understand it, relativistic effects such as time dilation & Lorentz contraction apply only when two observers are moving relative to one another *through* space: If the space between them is expanding or contracting (and therefore...
This is a instance of the the group velocity of the frequencies that make up an optical pulse exceeding c. It is a well-studied phenomenon and does not lead to a problem with relativity. The following link contains a discussion of the experiments described in your article...
In a sense, there's no point in trying to figure out what anyone will observe when they are traveling at the speed of light, because from their frame of reference, Lorentz contraction will have made the size of the universe (in the direction of their travel) zero: the universe will be, to them...
I think we might be losing sight of the fact that velocities in excess of C are impossible from the perspective of the OBSERVER. Sure, you can see two photons going in opposite directions, each moving at c - giving you a "calculated" relative velocity between them of 2c (from your point of...