What is the relationship between the index of refraction and the amount of refraction a ray experiences?
The index of refraction is the basic measure of the amount of refraction a light ray undergoes when passing from one medium to another. It is a measure of the relative value of the speed of light in a vacuum compared to the speed of light in the new medium, that is refractive index = speed of light in a vacuum / speed of light in the medium Since the speed of light in a vacuum is its absolute maximum, and it slows down when it passes into another medium, the refractive index is always greater than 1. The greater the value of the refractive index, the greater the refraction. It is usually employed in determining the angle of refraction (r) to the angle of incidence (i) at the interface between two media, by means of Snell’s Law : Refractive index = (sin i) / (sin r) Look up Snell’s Law for more detail.
