quote:
Originally posted by a philistine:
The speed of light (actually any electromagnetic radiation: radio waves, x-rays, gamma rays, etc.) in a vacuum is a constant (roughly 3x10^8 m/s) and that is what the "c" refers to in such equations as E=mc^2.
The speed that light travels is lower than c in various media (e.g. water, atmosphere, glass).
--A Philistine
Correct me if I'm wrong but wasn't light made to go faster than c quite recently (quite odd concept, light travelling faster than the speed of light..)