Donald Saari, Professor of Mathematics at Northwestern University and an internationally
known authority on chaos theory, delivered the 1995 Pollard Memorial Lecture on April 26.
The Pollard Lecture was scheduled as part of the department's celebration of Math
Awareness Week, April 23-29.
In his talk entitled "Chaos and the Evolution of the Universe," Saari began with some reminiscences of his years as a graduate student at Purdue and his study of celestial mechanics under the direction of the late Harry Pollard, who was Professor of Mathematics at Purdue from 1961 until his death in 1985. (Celestial mechanics investigates the sort of motions that planetary systems or systems of stars can have.) Saari then gave an entertaining introduction to chaos theory and explained how it is related to celestial mechanics and to some of his own recent work.
Saari received his Ph.D. from Purdue in 1967 and spent a year at Yale University before joining the faculty at Northwestern, where he served as chair of the department between 1981 and 1984. He has held visiting positions at the Eidgenössische Technische Hochschule in Zürich, the Federal University of Recife (Brazil), and the University of Paris, among others. Saari has published over one hundred mathematical papers, and in 1994 Spring-Verlag published his Geometry of Voting. In 1985, he was the recipient of the Lester R. Ford Award of the MAA. He has been a Guggenheim Fellow and holds a D.Sc. honoris causa from Purdue (Indianapolis). Saari recently won the MAA's 1995 Chauvenet Prize for his expository article "A visit to the Newtonian N-body problem via elementary complex variables," Amer. Math. Monthly, 97 (1990), 105-119.