Prof. Leonard Susskind derives the equations for the energy and pressure of a gas of weakly interacting particles, and develops the concepts of heat and work which lead to the first law of thermodynamics. Recorded on May 6, 2013.

1. Entropy and Conservation of Information
2. Temperature
3. Maximizing Entropy
4. The Boltzmann Distribution
5. Pressure of an Ideal Gas and Fluctuations
6. Weakly-interacting Gases, Heat, and Work
7. Entropy vs. Reversibility
8. Entropy, reversibility, and magnetism
9. The Ising model
10. Liquid-gas phase transition

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.