Color of Light

Author: J.B. Hoag

Light is known to consist of tiny waves. The distance from crest to crest or trough to trough of these waves is called the wave-length. The wave-length of light ranges from 0.000,04 to 0.000,08 cm., according to the color of the light. The red rays are the longest. Next in order of decreasing wave-lengths come the orange, yellow, green, blue, and violet rays. We shall use the symbol λ for the wave-length. It can be measured with very great accuracy by means of instruments called spectrometers.