Phase Transitions

This lecture introduces the concept of phase transitions, focusing on the critical point where the distinction between liquid and gas disappears, leading to phenomena like opalescence. The instructor explains the behavior of substances near the critical point, the divergence of correlation length, and the change in density between liquid and gas. The lecture also touches on the concept of metastability and the critical exponents that characterize phase transitions, providing insights into the complex behavior of matter at critical points.