Abstract
Photograph selected for the International Year of Light, 2015 "Light: Beyond the Bulb" project, an open-source international exhibition program for the International Year of Light to showcase the incredible variety of light-based science being researched today across the electro-magnetic spectrum, across scientific disciplines, and across technological platforms.
Sunlight is made up of a mixture of many wavelengths of light. Each visible wavelength is perceived as a different color, with violet having the shortest wavelength, and red the longest. When sunlight enters a raindrop, its path is bent; the light is "refracted." Each wavelength is bent slightly differently, with shorter wavelengths bent more than longer ones. This rainbow is caused by light being refracted (bent) when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. This causes the combined colors of sunlight to spread out into the familiar red, orange, yellow, green, blue, indigo, and violet of a rainbow. Here we see a rainbow as it appears to touch down over a cow in New Zealand.