"Version: 20171201"--Title page verso."A Morgan & Claypool publication as part of IOP Concise Physics"--Title page verso.Includes bibliographical references.1. Least action -- 1.1. Optics -- 1.2. Newtonian dynamics -- 1.3. Conservation lawsA. Calculus of variation -- B. Mathematics of conservation laws2. Special relativity -- 2.1. The postulates -- 2.2. Lorentz transformations -- 2.3. An analog…