The Evolution of Bodies Bound by Gravity

Bodies bound by gravity can evolve in surprising ways. In accord with everyday experience and physical law, heat flows from regions of high to low temperature, and angular momentum from regions of fast to slow spin. However, counter to intuition, in bodies supported by thermal pressure, the hot regions become hotter, whereas in those supported by rotation, the regions of rapid spin spinup. In this public lecture, Peter Goldreich, Professor Emeritus in the School of Natural Sciences, explains this behavior and describes its ultimate consequences.