Here are some things you may not have known about rainbows.
- No two people see the same rainbow, in fact even our individual eyes see slightly different rainbows. If someone appears to be standing under a rainbow you can see, they will see a different rainbow at the same angle but further away.
- The sky within a primary rainbow is brighter than the sky outside of the arc. This is due to the fact that the millions of droplets needed to make a rainbow are spherical and overlap to create white light. At the edge however, these colored discs don’t overlap so display their individual colors producing the rainbow arc.
- A “double rainbow” is where a second, much fainter arc can be seen outside of the primary arc. This is caused by the light reflecting twice inside the water droplets. As a result of this double reflection the colors of the second arc are inverted with violet on the outer edge and red on the inner edge.
- The dark, unlit sky between the primary arc and secondary arc is called Alexander’s band, after Alexander of Aphrodisias who first described it in 200 AD.
- In 1666, Isaac Newton added indigo and orange to give us the seven-colored Roy G. Biv that we all know and love today. However, in China rainbows are considerer to contain just five colors.
- A “moonbow” is a rare lunar rainbow or night time rainbow produced by light from the moon. Our eyes see it as white even though all colors are faintly present.