Prof. Leonard Susskind continues the discussion of reversibility by calculating the small but finite probability that all molecules of a gas collect in one half of a room. He then introduces the statistical mechanics of magnetism. Recorded on May 20, 2013.
Statistical mechanics is a branch of physics that applies probability theory to the study of the thermodynamic behavior of systems composed of a large number of particles. Statistical mechanics provides a framework for relating the microscopic properties of individual atoms and molecules to the macroscopic bulk properties of materials that can be observed in everyday life. Thus it explains thermodynamics as a result of the classical and quantum-mechanical descriptions of statistics and mechanics at the microscopic level.