Question

How is wave refraction measured?

Answer 1

Refraction is usually measured by comparing the sine of the angle of incidence to the sine of the angle of refraction. It is vital these are measured to the normal not to the interface.

Explanation:

So, all you need to do is measure the two angles and then find the sine of those angles. In my experience the uncertainty is large, so you are recommended to measure both angles several times, moving the light source each time.

This allows you to calculate the refractive index `n` of the material, which is defined as `n = (sin i)/(sin r)`, and generally has a value `1.003 < n < 2.43`.

From this you can find the speed of light in the material as `n = (c(vacu um))/(c(material))`