ROY G. BIV VIB G.YOR – Double Rainbows

Why are there so many songs about rainbows
And what’s on the other side?
Rainbows are visions, but only illusions.
- Kermit the Frog

It must be a Jim Henson week.

It rained again yesterday. The rain for the past several days has been odd.

The clouds will rush in to cover up his sister, the sun and the sun will shine between, pushing and shoving to get ahead of her brother. You’d think that Mother Nature would have swatted these two in the head and told the to behave, but no. Three days now and there have been three stormy fights and each one has been the same. I think, like me, Mother Nature sometimes gets tired of telling her kids to play nice and get along and so she just lets them argue.

The nice thing about this sort of elemental in-fighting is that it leads to a natural phenomenon known as a rainbow. Or, in an especially rare case such as I saw yesterday, a double rainbow.

I have always wondered how double rainbows happens. I have seen them a total of 6 times in my life (oddly enough two of them have been this year).

As most people know, normal rainbows happen because light passes through a raindrop and refracts, or bends. This causes the light to sort of spread out, which makes all the colors that make up light to become individually visible.

Double rainbows are commonly called a secondary rainbow. You can identify a secondary rainbow because of the fact the the colors are reversed on the second, fainter rainbow.

A secondary rainbow happens because the light that is refracted once gets split. Part of the refracted light leaves the raindrop and becomes the main rainbow and another part bounces back through the raindrop again. Because it is bounced again, the colors become reversed and the light comes out at a slightly different angle than the original. The result is a fainter and reversed secondary rainbow.

That’s alot of science to explain something that is just really a spectacular natural fireworks display. I think I just prefer to think of rainbows as leprechaun lottery and double rainbows as a doubler ball. I don’t have to think nearly as hard if I do that.