Classical mechanics, as a subject, is broadly defined. The ultimate goal of mechanics is a complete description of the motion of particles and rigid bodies. To find x(t) (the position of a particle, say, as a function of time), we use Newton's laws, or an updated (special) relativistic form that relates changes in momenta to forces. Of course, for most interesting problems, it is not possible to solve the resulting second-order differential equations for x(t). So the content of classical mechanics is a variety of techniques for describing the motion of particles and systems of particles in the absence of an explicit solution. We encounter, in a course on classical mechanics, whatever set of tools an author or teacher has determined are most useful for a partial description of motion. Because of the wide variety of such tools, and the constraints of time and space, the particular set that is presented depends highly on the type of research, and even personality of the presenter.

This book, then, represents a point of view just as much as it contains information and techniques appropriate to further study in classical mechanics. It is the culmination of a set of courses I taught at Reed College, starting in 2005, that were all meant to provide a second semester of classical mechanics, generally to physics seniors. One version of the course has the catalog title “Classical Mechanics II”, the other “Classical Field Theory”.