how does light slow down considerably when it passes through one? i have always been told that lights speed remains constant. as with many questions, i have my own personaol theories for answers, but i want to find out for sure.
Then you need to understand (i) the difference between group velocity and phase velocity; (ii) the mechanism of optical conductivity in gasses and non-vacuum media (I have written lengthy essays on this somewhere in here) and (iii) how we actually detect what is moving at what speed in anything.Jim Beam said:i see. i knew that light speed only remained constant in a vacuum, but i suppose my true question was why it didn't remain so in a medium