Hundreds of years ago, rainbows are thought of as sign of God to foretell heavy rain or war. Many took it as a sign of the bridge between life and death while the Irish believed that it signifies a gold pot. Because of this natural phenomenon not known then, it was highly fascinating for kids and onlookers to see such vibrancy in a clear blue sky after heavy rain.
Rainbow essentially is the scattering of light through the droplets of water in the atmosphere after heavy rain when the sky is said to be extremely clear without many clouds. Sunlight enters the atmosphere and the clear droplets are scattered in the spectrum of light, which combines to make a white light (here, the source of light or sunlight). Rainbow, therefore, is very natural and signifies the contents of a white light and its various colours having different frequencies.
