The way rainbows work

We have all heard the tales of the pot of gold at the end of the rainbow and the little leprechaun that wants nothing but to grab that gold. If you want to keep believing these, then you can close this article right now. But for those science minded folks that want to know how those lights mysteriously appear in the sky, well then this is the right place to be.

Most people know that rainbows can occur when it is sunny and raining. But what a lot of people might not know is that rainbows can also occur around fog, sea spray or waterfalls.

Now here is where we debunk all the myths. A rainbow is an optical illusion meaning that it is not exactly in one spot in the sky. The location of the rainbow in the sky is affected by where you are standing and where the source of light is (normally the sun). The centre of the rainbow is in the antisolar point, which is the imaginary point opposite the sun, which basically means that the sun will normally be behind someone who is looking at a rainbow.

When the lights hits it water droplet it is refracted and it sort of bends, then it is reflected by the back of the water droplet and the same thing happens again and again when the light goes through other water droplets.

An interesting fact is that rainbows are actually full circles, and the aforementioned antisolar point is the centre of the circle. People in planes can sometimes see the full circle (like in the article cover), but because rainbows can only be formed by water droplets on the horizon that is why we only see arches. And because everyone’s horizons are a little bit different, everyone’s rainbows are different.

The colours are a bit more complex and have to do with the length of each wave. This is a good website with a nice explanation if you would like to learn more: https://www.nationalgeographic.org/encyclopedia/rainbow/