Sadly you’ll never taste that rainbow after running into it with your mouth open, and you’ll never get that little green-clad Irish fella’s pot of gold.
You’ll also never be able to go over the rainbow, way up high, like Dorothy sang about.
Heck – whilst I’m here bursting bubbles, I might as well let you know that you can’t reach the horizon!
Why can’t you reach the end of a rainbow?
Well, simply put it’s because rainbows are actually optical illusions rather than something physical or tangible.
A rainbow is formed because raindrops act like tiny little prisms.
Raindrops refract and internally reflect the light of the sun towards you as you look at them.
Different wavelengths of light refract at different angles, so the sun’s white light is divided into the orderly set of huge arcing colors you see in a rainbow.
So, with this in mind, it makes fairly logical sense that when you move towards a rainbow, the angles you’re viewing it through change.
A rainbow will always be the same distance away from you.
For the colors of the rainbow to be created visually, the water droplets have to be a certain distance from you.
As you move towards the rainbow, it will always be the same distance away from you, so you can never reach it.
For a rainbow to remain constant, the angle between the sun, the droplet, and the observer has to be at 42 degrees.
If you can’t go over the rainbow, how do people take photos from an airplane?
Now, as I mentioned above, you’ll also never be able to go over the rainbow. Yet, there are still photos taken by people on airplanes of them flying over a rainbow. What’s that all about?
Well this is another optical illusion and it’s to do with aircraft windows having the property of birefringence.
Birefringence is the optical property of light being split into two rays when viewed through a material, with both rays having their colors dispersed differently too.
So as you look, light emerges from an aircraft window to your eyes, the two rays of light interfere with each other which creates the colored bands, similarly to what one would see when looking at a rainbow.
The effect is also enhanced by the polarizing effect of water as a back-drop for light. So this isn’t a rainbow, it just looks like one.
To sum up, you can’t go over the rainbow, and you certainly can’t reach its end. Killing off childhood dreams one fact at a time!