system
Given the following post, respond as if you're commenting on Reddit:
human
What is it about space-time that limits the speed of causality to something finite?

The standard answer to why the speed of light is finite usually just boils down to that the speed of causality is finite. Is there a deeper explanation? How does relativity theory calculate this speed?
gpt
Simply, because our experiments say so. It was one of the big headscratchers right around the turn of the previous century, that in all the experiments to measure the speed of light, they all came up with the same number *regardless of the frame of reference*. If you measured it on a train moving relative to the earth, you got the same number, if you measured it at the pole vs at the equator, you got the same number. The "Theory of Special Relativity" is about how Newtonian physics must be adjusted for the fact that *no (inertial) reference frame is special* (note that the two uses of "special" are totally different: Special Relativity is merely a special case of General Relativity, while "no reference frame is special" means in the "unique or different" sense). This "all frames are equal" thing implied, via some very simple math (like, decent middle school students could be walked through it reasonably well), that going faster than the maximum speed (which is also the speed that electromagnetic radiation travels at) results in being able to construct time paradoxes and make effects happen before causes. We don't know *why* the math worked out this way, per se, but we *do* know that this mathematical framework we built for "no reference frame is special" describes the physical universe as we see it.