A rainbow is caused by sunlight and atmospheric conditions. Light enters a water droplet, slowing down and bending as it goes from air to denser water. The light reflects off the inside of the droplet, separating into its component wavelengths--or colors. When light exits the droplet, it makes a rainbow.
If you had no idea at all about what a rainbow is or what causes it, you might actually believe some of the legends that different ancient cultures have created to explain it. Rainbows are among the most beautiful of nature’s displays.
A rainbow isn’t really a “thing” and it doesn’t exist in a particular “place.” It is an optical phenomenon that appears when sunlight and atmospheric conditions are just right—and the viewer’s position is just right to see it.
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