"Version: 20210201"--Title page verso.Includes bibliographical references.1. Introduction -- 1.1. Goals of the lecture notes -- 1.2. Classical electrodynamics and its symmetries -- 1.3. Field quantization -- 1.4. The need for discreteness in quantum computing -- 1.5. Symmetries and predictive models2. Classical field theory -- 2.1. Classical action, equations of motion and symmetries -- 2.2. Tr…