How Did One Equation Predict Antimatter and Spin?

Explore a detailed physics lecture that walks through the solutions of the Dirac Equation and reveals its profound implications for modern physics. Beginning with solutions for particles at rest, discover how this remarkable equation mathematically predicts the existence of antiparticles through its negative-energy solutions. Follow the step-by-step analysis as it extends to particles in motion, demonstrating how the energy-momentum relation naturally emerges from the mathematics. Learn about the deep connection between spin and symmetry, and understand how intrinsic angular momentum (spin-½) arises as an inherent feature of relativistic quantum theory. This hour-long exploration serves as the second part of a series examining how a single equation revolutionized our understanding of fundamental physics by predicting both antimatter and spin.