Physics 303 2007 Lecture summaries and lecture notes.

These are the lecture notes for Physics 303 - Statistical Physics taught in Fall 2007. This course was taught from mandl - a book I particularly liked as a student. However, Mandl is not so suitable for a Stat. Phys. Course which must of necessity include a reasonable amount of thermo as well.

How to read these lecture notes: Each page has 4 panels, representing a chunk of blackboard about 3 feet wide. The sequence of panels on a page is TL, TR, BL, BR. A 55 minute lecture is usually ten panels, 2.5 pages.

Note on errata: I'd be grateful, if you find a mistake, if you let me know so I can note it here.

Acknowledgements: Thanks to Kay Warner and John Daise for scanning these notes.

- Lecture 1 09/03/2007 Micro vs. Macro: the ideas of statistical physics. From Newtonian mechanics to thermodynamics. The laws of thermodynamics.
- Lecture 2 09/05/2007 Thermal concepts: temperature, heat, pressure. Speciﬁc heat. Thermometers. The ideal gas. Thermal expansion.
- Lecture 3 09/07/2007 The First Law. Thermodynamic Processes.
- Lecture 4 09/10/2007 Thermodynamic processes. Reversible and Irreversible processes. Quasistatic processes. Isothermal compression of a gas.
- Lecture 5 09/12/2007 Irreversible work and hysteresis. Cycles. Speciﬁc heats of an ideal gas. Adiabatic processes in an ideal gas - adiabats.
- Lecture 6 09/14/2007 Kinetic theory of the ideal gas. Equipartition. Real gases and van der Waals equation.
- Lecture 7 09/17/2007 Extensive and intensive qtys. Equilibrium, entropy and counting micro-states.
- Lecture 8 09/19/2007 S = k ln Ω. Equilibrium of an Isolated system.
- Lecture 9 09/21/2007 Application: The Schottky defect. Equilibrium of a system in a heat bath.
- Lecture 10 09/24/2007 System in a heat bath. Probabilities in physics - problems of interpretation. Deﬁnition of macroscopic energy as mean energy.
- Lecture 11 09/26/2007 Mean energy - statistical and thermodynamic deﬁnition of energy. Fluctuations. Mean square deviation - variance. Relation to heat capacity.
- Lecture 12 09/28/2007 Deﬁnition of Pressure. Density of states. Deﬁnition of entropy for a system in a heat bath. Canonical Ensemble.
- Lecture 13 10/01/2007 Ensembles - the microcanonical and canonical ensembles. The Helmholtz free energy and the zero-fluctuation limit.
- Lecture 14 10/03/2007Magnetic work. The paramagnetic solid in a heat bath. Magnetization and heat capacity.
- Lecture 15 10/05/2007 High and low field limits. The Curie law. Entropy and order in Magnetic systems.
- Lecture 16 10/08/2007 Entropy and order in Magnetic systems. Negative Temperature
- Lecture 17 10/10/2007 Ferromagnetism and the Curie-Weiss Law
- Lecture 18 10/12/2007 The Second Law for inﬁnitesimal changes.
- Lecture 19 10/22/2007 The second law for inﬁnitesimal changes. The fundamental thermodynamic relation.
- Lecture 20 10/24/2007 Reversible changes. Entropy of ideal gas. Clausius inequality. Simple applications: heating water, temperature equilibration.
- Lecture 21 10/26/2007 Maximum work. Thermodynamic potentials.
- Lecture 22 10/29/2007 Maxwell relations. The third law and its consequences. Maxwell relations for magnetic systems.
- Lecture 23 10/31/2007 The Clausius and Kelvin statements of the second law. Heat engines and refrigerators.
- Lecture 24 11/02/2007 Adiabatic cooling.
- Lecture 25 11/05/2007 Basic properties of the heat capacity of solids. The Equipartition Theorem. Dulong-Petit law and the third law of thermodynamics.
- Lecture 26 11/07/2007 The Einstein theory. Low and high temperature limits of the Einstein theory. Comparison of the Einstein theory with experiment.
- Lecture 27 11/09/2007 Debye’s theory. Mode counting and the density of states.
- Lecture 28 11/12/2007 Mode counting and the density of states
- Lecture 29 11/14/2007 Debye theory. Mean energy and Heat Capacity
- Lecture 30 11/16/2007 Phase Equilibria. The Chemical Potential. The equilibrium condition and phase diagrams
- Lecture 31 11/19/2007 The critical point. Geometric interpretation of thermodynamic potentials. Isotherms for a gas in equilibrium with its vapour.
- Lecture 32 11/26/2007 Perfect gases: the partition function for a quantal gas. The occupation number representation. The classical limit as the low-occupation number limit. Restrictions on occupation numbers. Bosons and Fermions.
- Lecture 33 11/28/2007 Statistics and symmetry. Statistic and spin. Bosons example: a perfect gas of photons. Partition function for photons. Black body radiation. Plancks law
- Lecture 34 11/30/2007 Comparison of Planck’s law and Debye theory: Photons and Phonons. Properties and thermodynamics of Black Body Radiation.
- Lecture 35 12/03/2007 Systems with variable particle numbers. The Gibbs distribution. The Grand Partition Function and Gibbs Grand Potential. Mean occupation numbers for Bosons and Fermions.
- Lecture 36 12/05/2007 Fermi-Dirac Statistics. Behavior of mean occupation number for fermions at zero and non-zero temperature. Density of states for electrons. Energy distribution of electrons. Definition of the Fermi energy. Free electron theory of metals - absence of lattic-electron interaction at zero temperature in a perfect lattice.
- Lecture 37 12/07/2007 Absence of electron-electron scattering in free electrons at zero temperature. Electronic heat capacity of metals - failure of classical theory. Electronic heat capacity - quantum theory.
- Lecture 38 12/03/2007 Variation of chemical potential with temperature for fermions and bosons. Temperature dependence of ground state occupation for bosons. Bose-Einstein Condensation.
- Lecture 39 12/05/2007 Bose Einstein Condensation in liquid helium, superconductors and cold atoms
- Lecture 40 12/07/2007 Summary lecture.