[quote=@Crimmy]
[@Crimson Raven] C is the same in all reference frames.

Time intervals will differ between reference frames.
[/quote]

Yeah, different Time intervals. That's better. I was struggling to express the change in time.

That is because C is a constant. There is no known way to change C. Not even by amplified Gs.

Edit: well. Technically, C has inherit variance, but the variance is too small to really matter. (Pun not intented)