# InfoCoBuild

## Statistical Mechanics

Statistical Mechanics (Spring 2013, Stanford Univ.). Instructor: Professor Leonard Susskind. 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. (from theoreticalminimum.com)

 Lecture 01 - Entropy and Conservation of information Leonard Susskind begins with a brief review of probability theory, and then presents the concepts of entropy and conservation of information. Lecture 02 - Temperature Leonard Susskind presents the physics of temperature. Temperature is not a fundamental quantity, but is derived as the amount of energy required to add an incremental amount of entropy to a system. Lecture 03 - Maximizing entropy Leonard Susskind begins the derivation of the distribution of energy states that represents maximum entropy in a system at equilibrium. Lecture 04 - The Boltzmann distribution Leonard Susskind completes the derivation of the Boltzmann distribution of states of a system. This distribution describes a system in equilibrium and with maximum entropy. Lecture 05 - Pressure of an ideal gas and fluctuations Leonard Susskind presents the mathematical definition of pressure using the Helmholtz free energy, and then derives the famous equation of state for an ideal gas: pV = NkT. Lecture 06 - Weakly interacting gases, heat, and work 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. Lecture 07 - Entropy vs. reversibility The speed of sound in an ideal gas, A single harmonic oscillator in a heat bath, The second law of thermodynamics, Reversibility of classical mechanics, Chaos theory. Lecture 08 - Entropy, reversibility, and magnetism 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. Lecture 09 - The Ising model Leonard Susskind develops the Ising model of ferromagnetism to explain the mathematics of phase transitions. The one-dimensional Ising model does not exhibit phase transitions, but higher dimension models do. Lecture 10 - Liquid-gas phase transition Professor Susskind continues the discussion of phase transitions beginning with a review of the Ising model and then introduces the physics of the liquid-gas phase transition.

 References Statistical Mechanics (Spring, 2013) | The Theoretical Minimum 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.

 The Theoretical Minimum Courses Classical Mechanics (Fall 2007) Classical Mechanics (Fall 2011) Quantum Mechanics (Winter 2008) Quantum Mechanics (Winter 2012) Advanced Quantum Mechanics (Fall 2013) Special Relativity (Spring 2008) Special Relativity (Spring 2012) Einstein's General Theory of Relativity (Fall 2008) General Relativity (Fall 2012) Cosmology (Winter 2009) Cosmology (Winter 2013) Statistical Mechanics (Spring 2009) Statistical Mechanics (Spring 2013) Particle Physics 1: Basic Concepts (Fall 2009) Particle Physics 2: Standard Model (Spring 2010) Particle Physics 3: Supersymmetry and Grand Unification (Spring 2010) String Theory and M-Theory (Fall 2010) Topics in String Theory (Cosmology and Black Holes) (Winter 2011) Quantum Entanglements, Part 1 (Fall 2006) Relativity (Spring 2007)