rainbows

The rainbow is one of the most well-known optical effects related to weather. As a child, everyone is excited to see a rainbow in the sky and marvel at its beauty. The colors of the rainbow can be so pure and brilliant that no photo does justice in imaging this phenomenon.
Contrary to what many people think, even scientists, the rainbow remains not very well understood, even though books and many articles have been written about it. We know how it is formed, generally; but the literature contains numerous observations, even photos of rainbow phenomena that can't be explained well or at all.
The rainbow is caused by light from the sun or moon interacting with raindrops falling from the air. These raindrops are mostly round. A ray of light entering such a droplet is bent and decomposed into all possible wavelengths which the white light consists of. The ray then reflects internally in the dr...