The Hill-Brown Theory of the Moon's Motion

This book, in three parts, describes three phases in the development of the modern theory and calculation of the Moon's motion-the last of which, in 1984, resulted in the transfer in the responsibility of producing lunar tables from the Nautical Almanac Office in Washington, D.C., to the Jet Propulsion Laboratory in Pasadena, CA-definitively ending an era. The mathematical, philosophical, and historical interest in the analytic solution to the lunar problem using the Hill-Brown method still engages celestial mechanicians and is the primary focus of this work.

Part I explains the crisis in lunar theory in the 1870s that led G.W. Hill to lay a new foundation for an analytic solution, a preliminary orbit he called the "variational curve." Part II is devoted to E.W. Brown's completion of the new theory as a series of successive perturbations of Hill's variational curve. Part III describes the revolutionary developments in time-measurement and the determination of Earth-Moon and Earth-planet distances that led to the retirement of the Hill-Brown theory in 1984.

The book uses some calculus and differential equations, but the text is largely understandable without advanced knowledge in these areas. Amateurs of astronomy, as well as instructors and scholars of the general history of science, would find this book of significant interest.