system
Given the following post, respond as if you're commenting on Reddit:
human
Is it possible to slow a photon down?

Is there any way of reducing the speed of a photon, or making it stationary? (in our frame of reference)
gpt
No.

You might be thinking of the way light "slows down" in a medium (glass, air, whatever), but what is actually happening is light is travelling at *c* between the atoms that make up the material, but being absorbed and re-emited by the atoms. This process takes a little time, so the overall macroscopic effect is that a light beam seems to slow down.