Refraction

The refraction of light is the change of direction of the light rays that happens after passing these from one medium to another in which the light propagates with different speed. It is governed by two principles or laws of refraction:

The incident ray, the refracted and the normal to the surface at the point of incidence are in the same plane.

Snell's law of refraction, which marks the relationship between the angle of incidence i, that of refraction r, and the absolute refractive indices of light in means 1 and 2, n1 and n2, according to:                                                  

“sin(iˆ)sin(rˆ)=n2n1”

The refraction of light occurs when it passes from a transparent medium with a certain index of refraction to another, also transparent, with a different one. Observe, in the image on the left, that when the velocity of propagation in the new medium is lower, and therefore the refractive index is higher, the ray approaches normal. In the image on the right we see the opposite case, in which the ray moves away from the normal one.

Sample:

A diamond has an index of refraction of 2.4. What is the speed of light within the diamond?

Answer:

1.25 x10

$^8$start superscript, 8, end superscript

 m/s