The light speed of light in water is c/n, where n=1.33 is the index of refraction of water. Thus, the speed of light in water is less than c. Why doesn’t this violate the speed of light postulate?

Question

asnaseer · Answer

The postulate states: As measured in any inertial frame of reference, light is always propagated in empty space with a definite velocity c that is independent of the state of motion of the emitting body. OR: The speed of light in free space has the same value C in all inertial frames of reference. Taken from wiki here: http://en.wikipedia.org/wiki/Postulates_of_special_relativity So this has not violated the postulate as it is talking about the speed of light in water - not empty space.

poofypenguin · Answer

That seems to be logical! Thanks!

asnaseer · Answer

yw

unklerhaukus · Answer

The speed of light is only $c=2.9979\times10^8 \frac{\text m}{\text {s}}$ in a vacuum