Understanding the dynamical evolution of dense stellar systems, such as globular clusters and galactic nuclei, is one of the most fundamental problems of gravitational astrophysics. Substantial progress towards this goal has been made in recent years as a result of both theoretical and observational advances. Frequent star-star gravitational interactions cause a profound evolution of the overall structure of these systems on astrophysically interesting time scales. Powerful computer simulation methods have firmly established the inevitable evolution of globular clusters of stars toward the collapse of the core of the cluster. The advent of new observing instrumentation and the ability to achieve high angular resolution from ground based observatories have both led to significant advances in the observational study of globular clusters and galactic nuclei. Drs. Cohn, Lugger, and Durisen, at the University of Indiana, have undertaken a major research effort to extend our understanding of stellar cluster evolution. Supercomputers have become an essential tool in this investigation. Globular clusters provide an excellent laboratory for observational tests of the stellar dynamical theory that underlies this group's models of normal and active galactic nuclei. The wealth of observational data on the structure of globular clusters and galactic nuclei that is being acquired by this group and others provides a firm basis for the theoretical modeling.
