- #26

PAllen

Science Advisor

2019 Award

- 8,162

- 1,424

1) Lorentz covariance with c is a universal principle that must apply to all physical laws, and that light traveling at c is true only to the extent Maxwell equations are exact (that is Lorentz covariance is more fundamental, and there could be a Lorentz covariant alternative to Maxwell's equations in which light travels at c-epsilon, which is found to be true without abolishing SR).

2) No information (matter and energy are special cases) of any kind can travel > c (the Lorentz constant) in an inertial frame. This makes the null cone structure of spacetime fundamental, and is definitely a prediction in that it applies to all conceivable mechanisms (now and 'forever' unless dis-proven). This makes the causal structure of spacetime fundamental, allowing SR to be built from this starting point.

(Note that all predictions of these are still compatible with suitably generized LET, as far as I know).