'This is the first book to provide a unified treatment of the two main subjects in astrophysical dynamics: the study of systems like the solar system that contain only a handful of planets, and the study of systems like star clusters and galaxies that contain millions or billions of stars. With remarkable brevity, clarity, and focus, Ryden has extracted the most important physical principles of both subjects at a level suitable for any reader with a basic background in classical mechanics.' Scott Tremaine, Institute for Advanced Study, Princeton

'How refreshing to read a book that covers so many different aspects of dynamical astronomy in such an authoritative and absorbing style! The book adeptly takes the reader on a journey from the two-body problem to the two-galaxy problem complete with appropriate nods to the subject's rich history. One of the text's real strengths is that it highlights the physical principles common to systems on a wide variety of scales.' Carl Murray, Queen Mary University of London

'This book is interesting, comprehensive, and clearly written. It gives historical and observational context in a delightfully light and informative way, and tackles the mathematics of celestial dynamics and stellar dynamics. These two related topics are exceptionally timely as they apply to the very active fields of exoplanets and Galactic dynamics respectively.' Carole Haswell, The Open University