An explanation. . .
ABC Australia – Iridescent Clouds – Hosted by Nate Byrne
It’s not really a rainbow, even though it looks a little like one. It’s called iridescence and just like a rainbow, it appears when sunlight shines into tiny moisture droplets in the air.
But what happens inside the droplets to create iridescence is very different to what happens when rainbows are formed. And in fact, if you look carefully, you’ll see that iridescent colours are kind of shiny and a little bit different to the colours of a rainbow.
What happens to sunlight inside a raindrop, why rainbow colours are always in the same order and what the real shape of a rainbow is and it’s not an arch.