It is the speed of cause and effect.
If something changes at location X, that cannot cause anything to change at location Y faster than the distance between X and Y divided by the speed of light.
Light (in a vacuum) goes as fast as the speed of cause and effect. And it just so happens that the speed of light is pretty easy to measure (as compared to other possible things).
So if we were all blind, we would still be affected by this speed.
Light (in a vacuum) goes as fast as the speed of cause and effect. And it just so happens that the speed of light is pretty easy to measure (as compared to other possible things).
So if we were all blind, we would still be affected by this speed.