Double Rainbow

The reward for the torrential rain yet again today was a double rainbow. I admit this is not the most glamourous setting for a double rainbow, but it will have to do.

As you all know, a rainbow is created when sunlight hits raindrops, and the light as it passes through is refracted. Red light has a longer wavelength than blue light and so bends less. This is why rainbows always have a longer red band at the top and a shorter blue band at the bottom.A double rainbow is created when the light is reflected twice off the raindrops. The second reflection has less light so the second rainbow is dimmer as well as upside down.

1520 Portrait of Richard III. Unknown, British School [Public domain], via Wikimedia Commons

In the UK we remember the colours of the spectrum, or rainbow with the mnenomic, “Richard of York gave battle in vain” – red, orange, yellow, green, blue, indigo and violet. This relates to the War of the Roses. The Yorkist Richard III lost the battle, and his life in 1485, to the Lancastrian Henry Tudor who became Henry VII. This saw the transition of the British monarchy from the Plantagenets to the Tudors. I presume that this mnenomic is not used in other parts of the world.