The Irish physicist John Tyndall (1820-1893) is best known for his work on the scattering of light by atmospheric particles and on the absorption of infrared radiation by gases. He also did much to popularize science among laymen.

John Tyndall was born on Aug. 2, 1820, at Leighlin Bridge, near Carlow, Ireland, where his father was a constable. After a little formal schooling, he gained a practical education by working as a surveyor and engineer. He entered the University of Marburg, Germany, in 1848 and earned his doctorate 2 years later. His dissertation research interested Michael Faraday, who later brought him to the Royal Institution of London. In 1867 Tyndall succeeded Faraday as superintendent there. He retired in 1887.

Tyndall is noted for his study of the scattering of light by atmospheric particles, a phenomenon sometimes called the Tyndall effect. In 1869 he provided explanations for the color of the sun at the horizon and...