Petra, and ALL
To find HOW you understood it was valuable. To expand; Tom has not yet 'taken on' Georgina's thesis in the 'Time Travel' Blog, so I interceded with this; It includes the logical analysis of the key issue, with thanks to Akira for confirming correct application.
"Tom,
Would you agree Einstein said, in the SR Postulates, that - The speed of light C and the laws of physics are the same IN all inertial frames. ?
If so, there are two ways to consider that.
1) That if we 'go to' and are 'moving with' or at rest 'with respect to' each inertial frame (simply 'condition of motion') we will find the postulates correct.
The second is;
2) That we don't need to bother to go there, to get IN each inertial frame to find out as we can observe it from any one of infinitely many other inertial frames and expect our measurements to be correct and the postulates to still apply to our observations.
What I, and I believe Georgina, suggest is that we suffered a failure of conceptual logic and assumed both must be true when perhaps only 1) was true, in which case we may expect to see c plus v in our 'observed' reality, and have to learn how to use mathematics to subtract the v to get the 'real' result. i.e. No LT, paradoxes or anomalies. (the LT was a 'fudge' to patch over the gaping hole in our logic)
In logic, Galilean Relativity was extended 'syntatically', which adds assumptions and freely increases predictions by allowing in contradictions. If we try to rely an axioms to suppress original axioms validity is lost. Logic demands monotonicity. Our over reliance on maths and loss of focus on logic allowed us to assume No 2) above was also true. That assumption cannot possibly be logically valid.
In this case, and with the only other logic possible, that of discrete 'body's or fields, as reference frames, physics becomes far simpler, as Einstein, Feynman and others predicted it would be when the answer was found.
Where on Ear... .. ...Vulcan was Mr Spock when we needed him!?
Peter