A Natural Example of Dispersion

© Department of Atmospheric Sciences,
University of Illinois at Urbana-Champaign
Used by permission

Rainbows are very common occurences after a rain shower, while the sun is still shining.
Rainbows form when light coming from the sun is refracted by the water droplets present in the atmosphere.

White light which is a mixture of colours, is then separated into its different wavelengths: this phenomenon is called dispersion.

Most of this refracted light passes through the droplet.
However, some of it is reflected internally back into the droplet. The light is refracted once more when leaving the droplet: the wavelengths are further separated and reach our eyes as the r a i n b o w colours.

Let's look at the fizzicks of the rainbow ...