Copyright 1999 Rebecca McDowell.
Basic diagram showing formation of rainbow.
The formation of a rainbow involves a series of physical
phenomena - reflection, refraction, dispersion and total internal reflection.
Light from Sun strikes raindrop
2. Some of the light is reflected
3. The rest of the light is refracted
4. Light splits into component colours
5. Reflected at rear of raindrop (TIR)
6. Refracted again as it leaves raindrop
7. Colours are further dispersed
Click on the links above for more detail on ech step.
When light from the sun hits a water droplet,
some of the light is reflected. This light will obey the Law