Celestial Mechanics

I was delighted to be invited by my colleagues Alessandra Celletti and Ettore Perozzi to provide a foreword to their book, Celestial Mechanics: The Waltz of the Planets. Having known them for many years and long admired their work in the subject so many of us love and are fascinated by, 1 read with great attention and pleasure the text when it arrived. It is a formidable task they have set themsel...