Rainbows are one of the most beautiful things that we see in the sky during the day. They are the circular arcs formed by the Sun’s rays and water droplets in the Earth’s atmosphere. For thousands of years, mathematicians and scientists wondered about its mystery. Is there a mathematical explanation why rainbows appear as they do?

The video below shows a modern analysis of the structure and the mathematics of rainbows. What is surprising is that the modern explanation is very similar to that of Aristotle’s theory who lived about 300 BC. The mathematics involved are parallel lines, circles, and arcs. Continue reading