Somewhere under the rainbow, gazing up in awe
I DON’T know how many rainbows I have seen in my lifetime, but they never fail to stop you in your tracks, uttering the same kind of admiring ‘Aaahh’ as during a concert light show or firework display.
Whatever the meteorological explanations, rainbows always appear like a natural miracle: the satisfying arc shape, the combination of colours as sunlight and raindrops collide and the fact that, like an optical illusion, the closer you move to it the more it retreats, always keeping its elusive pot of gold at a distance. The physical process of refraction that splits light into its spectrum also comes with a quiz – how does one remember the order of colours? I was always taught to recount them with the mnemonic: Richard Of York Gained Battle In Vain. Red, orange, yellow, green, blue, indigo, violet. Though ‘indigo’ throws me. The other contrasting colours seem well defined, but the gradation between blue and violet is a pretty subtle one.
I spotted a rainbow over Dartmoor at the weekend, and a fleeting hint of a second arc above. Interestingly, a primary rainbow has red on the outside of the arc and violet as the inner band, while in a double rainbow the order of colours is reversed, with red on the inner side. This is apparently caused by light being reflected twice on the inside of the rain droplets.
Dartmoor is a good place for rainbows – being as there is a decent supply of rain. But the most vivid I ever saw was late last year travelling north to Exmoor, the conditions obviously perfect and the bars of colours staggeringly vibrant. I was driving and unable to take a photo, though, even if I had, no one would have believed I hadn’t tinkered with the saturation in Photoshop.
On the same stretch of road many years ago I witnessed a magical phenomenon at night, and did stop the car in a layby to marvel: a moonbow. Exactly the same idea as a rainbow, but created by strong moonlight and light drizzle. I had to look it up to check there was even a word for it. Wonders never cease.