Norrish, Ronald George Wreyford (1897-1978)

English physical chemist who studied fast chemical reactions, particularly those initiated by light. He shared the 1967 Nobel Prize for Chemistry with his co-worker George Porter. Norrish was largely responsible for the advance of reaction kinetics to a distinct discipline within physical chemistry. Norrish was born and educated in Cambridge and spent his academic career there, becoming professor 1937. Norrish began working in photochemistry in 1923. His interest in using intense flashes of light to initiate photochemical reactions seems to have been stimulated by his work during World War II with his student George Porter, investigating methods of suppressing the flash from guns and developing incendiary materials. By varying the time delay between two flashes, Norrish was able to study the kinetics of the formation and decay of very shortlived radicals or ions. Norrish went on to apply these techniques to the study of chain reactions. He also made pioneering studies of the kinetics of polymerization. He and his co-workers discovered the gel effect, which occurs in the later stages of free-radical polymerization.