What also surprised me is that the speed difference depending on medium is actually quite substantial. For example, glass has a refractive index of about 1.5.
So, the speed of light in glass is c/1.5 ≈ 200.000 km/s, i.e. 66% of the speed of light in vacuum.
What also surprised me is that the speed difference depending on medium is actually quite substantial. For example, glass has a refractive index of about 1.5.
So, the speed of light in glass is c/1.5 ≈ 200.000 km/s, i.e. 66% of the speed of light in vacuum.