Tyndall, John
Tyndall, John (1820-1893), a British physicist. Tyndall was one of the most eminent lecturers and writers of his day, especially noted for his efforts to popularize science. His most important original work was his research during 1859-71 on how gases and vapors absorb and transmit heat. Tyndall made the first detailed study (1869) of the way light is scattered by small particles, such as dust in the atmosphere. He proposed that this scattering—which came to be called the Tyndall effect—accounts for the blue color of the sky. (Another British physicist, Baron Rayleigh, later explained how the scattering causes the blueness of the sky.)
Tyndall was born in Ireland. After a short career as a surveyor and civil engineer, he became a teacher of mathematics and surveying in England. In 1848 he entered the University of Marburg in Germany, where he received a Ph.D. degree in 1850. After returning to England, Tyndall was elected to the Royal Society in 1852. He became professor of physics at the Royal Institution, London, in 1853 and served as its superintendent, 1867-87.