Originally Posted By: Bill 6
Responses pointing out that the big bang expanding universe as well as SR's light barrier have been ratified will be reminded of the principle of physics that whilst a theory may appear to be supported by numerous experiments it only takes one (repeatable) experiment to invalidate any theory.

But so far there have been a great many experiments that ratify SR, and none that don't. Likewise the expanding universe seems to be readily handled by GR. And of course once again GR has been ratified by a great many experiments, and there have been no experiments that don't ratify it. After a while you have to give up and accept that the probability that they are wrong is extremely low. When that happens it is generally accepted that they meet the requirements to be called natural law.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.