- #1
Swapnil
- 459
- 6
Photon Speed Same Always??
Hi there. I read the following in a wikipedia article (http://en.wikipedia.org/wiki/Cherenkov_radiation):
Can anyone help me out to make sense out of this statement? The speed of a light wave [tex]v = c/n[/tex] in a medium is DIFFERENT that what it is in free space. Then how can the speed at which the photons travel be the same??
Hi there. I read the following in a wikipedia article (http://en.wikipedia.org/wiki/Cherenkov_radiation):
It is important to note, however, that the speed at which the photons travel is always the same. That is, the speed of light, commonly designated as c, does not change. The light appears to travel more slowly while traversing a medium due to the frequent interactions of the photons with matter. This is similar to a train that, while moving, travels at a constant velocity. If such a train were to travel on a set of tracks with many stops it would appear to be moving more slowly overall, i.e. have a lower average velocity, despite having a constant higher velocity while moving.
Can anyone help me out to make sense out of this statement? The speed of a light wave [tex]v = c/n[/tex] in a medium is DIFFERENT that what it is in free space. Then how can the speed at which the photons travel be the same??
Last edited by a moderator: