SMALE, STEPHEN

born July 15, 1930, Flint, Mich., U.S. American mathematician who was awarded the Fields Medal in 1966 for his work in topology and dynamical systems. Educated initially in a one-room schoolhouse outside Flint, Smale attended the University of Michigan, where he received a bachelor's degree in chemistry (1952) and a doctorate in mathematics (1956). He began as a topologist at Columbia University, New York City, in 1961 but left the field to pursue research in dynamical systems. In 1964 he accepted a position at the University of California, Berkeley, where he stayed until his retirement. Smale was awarded the Fields Medal at the International Congress of Mathematicians in Moscow in 1966. During his years at Columbia and Berkeley he moved through various fields, including the calculus of variations and the study of infinite dimensional manifolds. Smale's most famous result was his proof of the Poincar conjecture for n 5. Smale's interests were not confined to purely mathematical fields. He became interested in mathematical economics after conversations with Berkeley Nobel laureate Gerard Debreu and later developed an interest in computer science, particularly the theory of algorithms. Smale's publications include, with Morris W. Hirsch, Differential Equations, Dynamical Systems, and Linear Algebra (1974); The Mathematics of Time: Essays on Dynamical Systems, Economic Processes, and Related Topics (1980); and Algorithms for Solving Equations (1986).