Sunday, October 2 1994, 12am Boyd Graduate Studies, Room 328 Dr. Persi Diaconis Harvard University Professor Persi Diaconis, Harvard University Dr. Diaconis's first lecture, for a general audience, is co-sponsored by the Humanities Center, under its Humanities Science Interface Initiative. In this talk, Dr. Diaconis will discuss how coincidences can astound us, affecting where we live and what we do. In addition to reviewing relevant work of Freud and Jung, he will show how, sometimes, a bit of quantitative thinking can show that coincidences are not so surprising after all. Dr. Diaconis's second lecture, for undergraduates in the mathematical sciences and mathematics education, will discuss amazing magic tricks which depend secretly on real mathematical constructions. Dr. Diaconis's third lecture is a mathematical colloquium. Typical large orthogonal matrices show remarkable structure in their eigenvalues. This same structure appears in particle scattering, zeros of the Riemann zeta function, and telephone encryption problems. It will be shown how symmetric function theory can be used to unravel the pattern.