What's the smallest rainbow?
The radius of a rainbow is determined by the water droplets' refractive index. A refractive index is how much a ray of light bends as it passes from one medium to another—from air to water, for example. A droplet with a high refractive index will help produce a rainbow with a smaller radius.
Join Alexa Answers
Help make Alexa smarter and share your knowledge with the worldLEARN MORE