Comment by tsimionescu
2 years ago
The point is that all of the speeds we measure are actually measured in units of the speed of light, if you go right down to it (seconds and meters are defined in terms of the speed of light). So, the value of the speed of light doesn't really matter - which is why c=1 is often used in many kinds of physics.
When people talk about changing the speed of light, they’re obviously not talking about that sort of bookkeeping.