What Causes A Rainbow? - Science | HowStuffWorks

Home » How The Rainbow Was Made » What Causes A Rainbow? - Science | HowStuffWorks

Maybe your like

It all starts with a prism. Imagine a triangular piece of glass or plastic. This prism is like a backstage magician in the rainbow-creating show. When white light enters one face of the prism, it's as if the magician whispers an incantation: "Separate!"

You see, light enters the prism, and the magic begins. This process of splitting is thanks to the refractive index of the glass. What's that, you ask? Every material, from air to water, has a different refractive index. This index dictates how much light bends as it travels from one medium to another.

Advertisement

Refraction and Dispersion: The Color-Making Trick

When light hits the prism, it bends, or refracts, thanks to the change in refractive index between air and glass. But it doesn't stop there; as the light continues through the prism, it separates into its various colors.

We call this process dispersion, and it's how a spectrum of colors — from red light with the longest wavelength to violet light with the shortest wavelength — is created.

What Are the Seven Colors of a Rainbow?

The colors of a rainbow are red, orange, yellow, green, blue, indigo and violet. It's the sequence you never forget: Roy G. Biv!

Advertisement

Tag » How The Rainbow Was Made