Lecture
This lecture covers the interpretation of the two-fold energy degeneracy in the free particle solutions of the Dirac equation, the non-commutativity of orbital angular momentum with the Dirac Hamiltonian, the definition of the 4x4 spin operator, the concept of helicity, and the discrete symmetries of Parity, Time Reversal, and Charge Conjugation in the context of the Dirac equation.