In this volume, a number of international authorities describe the ways in which the notion of chaos occurs and can be applied in a variety of contexts. The articles are based on talks presented at the Royal Society meetings held early in 1987 and range from the mathematical (ergodic theory) through astronomy, physics, renormalization theory, and turbulence. These state-of-the-art surveys will make this volume essential for all those working in the theory and application of chaotic dynamics.