eli5 how do we know nothing is faster than light?

Question

eli5 how do we know nothing is faster than light?

In: 452

Answer 1

Because as far as we can see, and calculate, the fabric of space-time is curved in such a way that the fastest possible speed between any two points in space-time is *c*, that is, 3×10^(8) m/s or so.

(Sort of like the shortest possible distance between any two points in space. But… with the added time-dimension.)

If the fabric of space-time were shaped differently, then maybe that speed would be different. But then if that were the case, a *ton* of experiments and observations we have done over the past 150 years would have all come out differently.