I Light Speed in Dense Medium: Explained

deedee6905
Messages
2
Reaction score
0
TL;DR Summary
Does light travel at the same speed?
If light goes from air through glass, the reason the light bends is because I'm told that the light travels slower inside the glass. If I change my observer reference to inside the glass, the speed of light inside the medium it look like light is still traveling at the speed of light? if so, the light from outside then would have to look like it is traveling faster than the speed of light. How does this actually work?
 
Physics news on Phys.org
Light only maintains its invariant speed ##c## in vacuum. It travels slower in media. Particles are routinely observed traveling faster than light in a medium (although never faster than ##c##). They slow down by emitting Cerenkov radiation.
 
Last edited:
  • Like
Likes sysprog and vanhees71
I asked a question here, probably over 15 years ago on entanglement and I appreciated the thoughtful answers I received back then. The intervening years haven't made me any more knowledgeable in physics, so forgive my naïveté ! If a have a piece of paper in an area of high gravity, lets say near a black hole, and I draw a triangle on this paper and 'measure' the angles of the triangle, will they add to 180 degrees? How about if I'm looking at this paper outside of the (reasonable)...
Thread 'Relativity of simultaneity in actuality'
I’m attaching two figures from the book, Basic concepts in relativity and QT, by Resnick and Halliday. They are describing the relativity of simultaneity from a theoretical pov, which I understand. Basically, the lightning strikes at AA’ and BB’ can be deemed simultaneous either in frame S, in which case they will not be simultaneous in frame S’, and vice versa. Only in one of the frames are the two events simultaneous, but not in both, and this claim of simultaneity can be done by either of...

Similar threads

Replies
5
Views
1K
Replies
5
Views
1K
Replies
11
Views
2K
Replies
6
Views
495
Replies
6
Views
2K
Replies
17
Views
2K
Replies
42
Views
796
Replies
3
Views
2K
Back
Top