A rainbow in the east will be followed by a fine morrow, in the west by a wet day.
Aren't rainbows wonderful? But what is a rainbow? What makes the bow? And why do people believe there's a pot of gold at the end of a rainbow?
A rainbow is sunlight spread out into its spectrum of colors and diverted to the eye of the observer by water droplets. The bow part of the word refers to the fact that the rainbow is a group of nearly circular arcs of color all having a common center.
The main ingredients to see a rainbow are the following:
Even as far back as the 17th century, people knew that we cannot see the complete circle of the rainbow. People in the 17th century became fond of saying that one was as likely to find a pot of gold as to find the end of the rainbow. The expression somehow changed, and became a part of mythology.