The Principle of Least Action

1. Introduction; 2. Prehistory of variational principles; 3. An excursio to Newton's Principia; 4. The optical-mechanical analogy, part I; 5. D'Alembert, Lagrange, and the statics-dynamics analogy; 6. The optical mechanical analogy, part II: the Hamilton–Jacobi equation; 7. Relativity and least action; 8. The road to quantum mechanics; Appendix A. Newton's solid of least resistance using calculus; Appendix B. Original statement of D'Alembert's principle; Appendix C. Equations of motion of MacCullagh's ether; Appendix D. Characteristic function for a parabolic Keplerian orbit; Appendix E. Saddle paths for reections on a mirror; Appendix F. Kinetic caustics from quantum motion in one dimension; Appendix G. Einstein's proof of the covariance of Maxwell's equations; Appendix H. Relativistic four vector potential; Appendix I. Ehrenfest's proof of the adiabatic theorem; References; Index.