A rainbow is nature's way of producing a spectrum. One can usually see rainbows after summer showers, early in the morning or late in the afternoon, when the sun is low. Rain drops act as tiny prisms and disperse the white sunlight into the form of a large beautiful arch composed of visible colors. To see a rainbow one must be located between the sun and raindrops forming an arc in the sky. When sunlight enters the raindrops at the proper angle, it is refracted by the raindrops, then reflected back at an angle. This creates a rainbow. Artificial rainbows can be produced by spiraling small droplets of water through a garden hose, with one's back to the sun. Or, indoors, diamond-shaped glass objects, mirrors, or other transparent items can be used.
Science EncyclopediaScience & Philosophy: Cluster compound to ConcupiscenceColor - Light And Color, Rainbows, Refraction: The Bending Of Light, Diffraction And Interference, Transparent, Translucent, And Opaque