Onsager, Lars

Onsager, Lars

(born Nov. 27, 1903, Oslo, Nor.—died Oct. 5, 1976, Coral Gables, Fla., U.S.) Norwegian-born U.S. chemist. He immigrated to the U.S. and taught principally at Yale University. His development of a general theory of irreversible chemical processes, described as the “fourth law of thermodynamics,” gained him a 1968 Nobel Prize. He also applied the laws of thermodynamics to systems not in equilibrium. His explanation of the movement of ions in solution as related to turbulence and fluid density had a major effect on the development of physical chemistry.

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Onsager, Lars (1903–76) chemist; born in Oslo, Norway. He came to the U.S.A. about 1928 when he was appointed associate in chemistry at Johns Hopkins; he then taught at Brown (1929–33) before becoming affiliated with Yale (1934–72). He demonstrated mathematically (1931) how simultaneous chemical reactions influence each other in ways now called Onsager's reciprocal relations. He was awarded the Nobel Prize in chemistry (1968).