Rainbow
Created | Updated Apr 25, 2002
A Rainbow is the the semi-circular arc that appears in the sky, usually after summer rain has fallen. There are reputedly 7 bands of colour in it but most people can only see 6. Sir Isaac Newton, who first explained how it was formed and studied it in depth, was, like 14% of the human population of Earth, colour blind, so he had to rely on the eyes of his assistant, which were equipped with seven-colour-perception, and were able therefore to discern a difference between indigo and violet. Lucky eh?
