Isaac Newton was the first person to experiment with light. He discovered that many colors are present within white light. He discovered that when light passes through a glass prism it is broken down into seven different colors. In his experiments, the light turned to white again when it passed through a second prism. This indicated that light isn't changed in any way by a prism, but rather a prism could be used to experiment on light, and uncover its hidden properties.
As light passes through a prism, a white light is separated into a spectrum of seven colors: red, orange, yellow, green, blue, indigo and violet. Schoolchildren are taught to remember the color spectrum with the mnemonic aid ROY-G-BIV. While the human eye sees white light, this energy source is made up of the seven main colors observed in a rainbow. Some prisms are designed to separate white light into its colored spectrum, while others only bend, or redirect light rays.
Using prisms, light rays can be directed along specific paths, depending on the prism's size and shape. High power binoculars and telescopes use prisms to bend the path that light travels in order to clearly focus on distant objects. When a set of the binoculars is examined, the lens that a person looks through are much closer together than the lens that look downrange. As the light enters the larger lens, the light rays are focused, bent and redirected to the eyepieces by prisms set within the binoculars.
When chemical elements burn, they give off light that contains specific light wavelengths. The emitted light will contain a unique set of color wavelengths, even though the light will look white, or whitish to the naked eye. Prisms are used in the science lab to determine the chemical that produced the light source. The light is separated into its color spectrum and the individual colors are analyzed. In a prism, the light refracted off the polished surface bends at different angles, depending on the light's wavelength. The result is a color pattern as distinct as a fingerprint. This optical fingerprint tells the scientist what elements are producing the light.
Prisms are also used when constructing high power lasers. The laser light source passes through a series of lenses and prisms that separate the light into its different wavelengths. The laser uses only a narrow wavelength light beam. The laser amplifiers the target light wavelength while the other wavelengths are discarded and unused within the laser. Within the laser optics, the prisms can be adjusted to select different light wavelengths, which makes the laser more versatile for a diverse universe of experiments.