Connection between classical mechanics and field theory

Professor Susskind begins the final lecture with a review and comparison of the three different concepts of momentum: mechanical momentum from Newtonian mechanics, canonical momentum from the Lagrangian formulation of mechanics, and momentum that is conserved by symmetry under translation invariance from Noether's theorem. He then develops the connection between Lagrangian and Hamiltonian mechanics and field theory in more detail than in previous lectures.

Professor Susskind moves on to develop the concepts of energy and momentum density, and then applies these concepts to electromagnetic fields. He concludes the course with an introduction to energy and momentum flux, and the stress-energy tensor.