God Answers the Question: "Why Rainbows?"
The miraculous rainbow is caused by the reflection of light in water, resulting in a multicolored arc across the sky. Sometime around 300 BC, the classical Greek scholar Aristotle gave a scientific explanation of the "spectrum of light" that lead to later works by Descartes in 1637. Yet, in the beginning, it was God who said:
This is the sign of the covenant that I make between me and you and every living creature that is with you, for all future generations: I have set my bow in the cloud, and it shall be a sign of the covenant between me and the earth.