Does light really slow down when moving through a transparent medium?

Question

I assume its speed doesn't change but the photons get absorbed and destructed by the materials' atoms and then they emit new photons. Is that true?

Possible duplicate of What is the mechanism behind the slowdown of light/photons in a transparent medium? — John Rennie, Oct 24 '17 at 12:45
See also What really causes light/photons to appear slower in media? — John Rennie, Oct 24 '17 at 12:46

score 0 · Answer 1 · answered Oct 24 '17 at 12:52

Light is an electromagnetic wave. It is an oscillation of electric and magnetic fields. The ability of these fields to oscillate depends on the medium the wave is travelling through. The least "resistance" is provided by the vacuum, so in a vacuum the speed is greatest.

In a material, the atoms (which have electric and magnetic fields themselves) influence the ability of the wave to oscillate and this has the effect of slowing the propagation.

The size of the effect (the factor by which is slowed down) is known as the refractive index of the material.

The OP clearly asks about the quantum view, not classical. – safesphere Oct 24 '17 at 14:35 — safesphere, Oct 24 '17 at 14:35

Does light really slow down when moving through a transparent medium?

1 Answers1