Refractive index of air

The refractive index of air is about 1 - the same as the refractive index of a vacuum.

That means light travels at roughly the same speed through air as it does through a vacuum.

flashcards

Question	Answer
What is the approximate refractive index of air?	About 1, the same as the refractive index of a vacuum.
What does a refractive index of about 1 for air imply about the speed of light?	Light travels at roughly the same speed through air as through a vacuum.