Why does a rainbow form?
Question
How does a rainbow form? Why are they those colours?Paul, New Addington
Answer
** Definitive **Name: Peter, Ruislip
Qualification: I saw a rainbow
Answer: A few weeks ago, we saw a rainbow whilst driving, and saw another fainter one further out, whose colours were reversed. So I looked it up. What happens is this: sunlight hits the raindrop and is refracted, so the different colours go in different directions and is refracted again when it comes out, enhancing the split. So when you look at that raindrop, you only see one colour as only one colour is heading in your direction. Different raindrops show you different colours, hence the colours of the rainbow. With the double rainbow, the colours get reflected twice around the raindrop and come out again, so it’s another angle of colour that you can see. Colours are just light of different wavelengths, so when you break it down into it’s constituent parts, these are the colours we can see.