Light enters a droplet
Refraction changes its direction and begins separating wavelengths.
Internal reflection redirects the light
Part of the light reflects from the back of the droplet.
Light exits at colour-dependent angles
A second refraction sends different wavelengths toward the observer at slightly different angles.
A rainbow is geometry as well as colour
Each observer sees light from a particular set of droplets.
Source trail: NASA: electromagnetic spectrum · NOAA: weather & atmosphere
This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.