GEORGE BERNARD / SCIENCE PHOTO LIBRARY GEORGE BERNARD / SCIENCE PHOTO LIBRARY
John Tyndall. Portrait of the Irish physicist John Tyndall (1820-93). Tyndall was a surveyor and engineer before studying physics and becoming a professor at the Royal Institution, London, in 1854. He was a prolific writer on a number of subjects. He studied light beams passing through various substances. In 1869 he discovered the Tyndall Effect in which light scattering by colloidal particles in a solution makes the light beam visible from the side. He realised that the sky is blue because dust particles in the air scatter the shorter blue wavelengths of sunlight more than the longer red wavelengths. Taken from the 1877 volume of Men of Mark and Distinction.
Model release not available. Property release not required.