Who is Lars Onsager? Information on Lars Onsager biography, life story, works and contributions to science.
Lars Onsager; (1903-1976), Norwegian-American chemist, who won the 1968 Nobel Prize in chemistry for his discovery of certain relations that are fundamental in the thermodynamics of irreversible processes. Onsager was born in Oslo, Norway, on Nov. 27, 1903. He obtained a degree in chemical engineering from the Norwegian Technical Institute in Trondheim in 1925, studied at the Federal Institute of Technology in Zurich, Switzerland, and then went to the United States in 1928. After teaching at Johns Hopkins and Brown universities, he became an assistant professor of chemistry at Yale University in 1934 and received his Ph.D. there in 1935. Onsager rose rapidly at Yale, becoming an associate professor in 1940 and J. Willard Gibbs professor of theoretical chemistry in 1945, the same year he became an American citizen. Onsager remained at Yale until 1972, when he transferred to the University of Miami in Coral Gables, Fla.
In 1931, Onsager developed a quantitative treatment of the thermodynamics of irreversible processes in systems whose departure from equilibrium is small. He adopted certain definitions for flow and force quantities, such as the flow of heat from a warm body to a cool one and the driving force for this flow. He then showed that in the equations governing such irreversible processes there are reciprocal relations between the coefficients of proportionality. These relations, called the Onsager reciprocal relations, later proved to be widely useful. For instance, his work in irreversible thermodynamics led to a theoretical description of the mechanisms whereby materials cross biological membranes.
In other work Onsager advanced the understanding of dielectrics and electrolytes and in 1939 proposed the gaseous-diffusion technique for isolating uranium-235, which was essential in producing the first atomic bomb.