Recent content by jahrudz

Then how can we know if our measurement of light is off from the "true" speed of light since we're measuring from a moving reference point, Earth?

I understand that c is the "ultimate speed" and that it is a result of the fundamental constant, the permeability of free space. But if this is a constant only to a "stationary" frame of reference, how can we accurately measure it from Earth? Since Earth is moving relative to a supposed "fixed"...