Adding to the fun - The light is still going the same speed within the medium, but it’s bumping into more things. Those collisions divert the light, lengthening the distance it travels through something like 1 cm of glass vs 1 cm in a vacuum. It changes the time it takes to travel through glass rather than the speed at which the light is moving.
At least that’s what I remember from a YouTube video.
It would also still be the speed of light. Always is, unless you specify ‘in a vacuum’ every time.
Adding to the fun - The light is still going the same speed within the medium, but it’s bumping into more things. Those collisions divert the light, lengthening the distance it travels through something like 1 cm of glass vs 1 cm in a vacuum. It changes the time it takes to travel through glass rather than the speed at which the light is moving.
At least that’s what I remember from a YouTube video.
Probably the Youtube video in question
Yes that’s it! Thanks for the link!!
The real fun starts when things move faster than the speed of light, that’s when you get Cherenkov radiation!