If light travels at the same speed in all media, then in what terms is it slowed down or sped up in refraction?

Question

If light travels at the same speed in all media, then in what terms is it slowed down or sped up in refraction?

In: Physics

Answer 1

Light is a group of photons. Individual photons isn’t considered light. Photons themselves don’t slow down, but they cover larger distances when they pass through mediums (such as air, or glass) since they scatter at different angles. That’s what it means for light to “slow down”.