Thermal and Statistical Physics
By Prof. Carlson
To listen to an audio podcast, mouse over the title and click Play. Open iTunes to download and subscribe to podcasts.
Thermal and Statistical Physics Purdue University Phys 416
||CleanLecture 4: Partition Function and Thermodynamic Identity||Boltzmann Factor, Partition Function and how to calculate everything else from it. Live near lakes because they have a high heat capacity. Energy and Heat Capacity of a two state system, Definition of a reversible process, Definition of pressure, The Ther||9/9/2007||Free||View In iTunes|
||CleanLecture 5: Free Energy and Maxwell Relations||Helmholtz Free Energy is the right energy to use when temperature and volume are used as control variables. Free Energy and the Partition Function. Maxwell Relations -- you can derive them all. Legendre Transforms. Ideal Gas. Quantum Concentration. Why so||9/9/2007||Free||View In iTunes|
||CleanLecture 6: Ideal Gas Law, Planck Blackbody Radiation||Deriving the ideal gas law. Equipartition Theorem. Entropy of Mixing. Hot things glow -- or how night vision goggles work (Planck blackbody radiation). Analyzing star spectra. Class discussions: Mixing 2 colors of Kool-Aid, and how to make heavy Kool-Aid||9/9/2007||Free||View In iTunes|
||CleanLecture 2: Multiplicity Function||Why is the most probable configuration important? Multiplicity Function is a gaussian in the two-state system. Weighted averages. Introduction to partition function. Lecture 2 Audio||9/9/2007||Free||View In iTunes|
||CleanFinal Review 2||This is a final review for the last 1/4 of the course. This is a very short lecture, because we had a field trip to go see the prestigious Bagwell Lecture given by Purdue's very own Prof. Albert Overhauser of the world-famous Overhauser Effect. Lecture Au||8/21/2007||Free||View In iTunes|
||CleanFinal Review 1||This is a final review for the first 3/4 of the course. Lecture Audio||8/21/2007||Free||View In iTunes|
||CleanLecture 24: Fluctuation-Dissipation Theorem||We finish two more examples of the Fluctuation-Dissipation Theorem. This is a theorem that pops up everywhere! It means that the very same microscopic processes responsible for establishing thermal equilibrium are the same microscopic processes that cause||8/21/2007||Free||View In iTunes|
||CleanLecture23: Brownian Motion and Diffusion||Brownian motion was discovered by a botanist named Brown, when he looked at water under a microscope, and observed pollen grains "jiggling" about in it. Einstein eventually explained it as due to the random collisions the pollen grain experienced from the||8/21/2007||Free||View In iTunes|
||CleanLecture 22: Nucleation in First Order (Abrupt) Phase Transitions||Supercooling Demonstration (thanks to special guest Prof. Ken Ritchie): Put filtered water in a plastic bottle in your freezer for, say, 4 hours. Now, carefully remove it from the freezer, and shake the bottle vigorously. We did this, and saw ice crystals||8/21/2007||Free||View In iTunes|
||CleanLecture 21: Alloys, Mixing, and Phase Separation||Oil and water -- they don't mix. Or do they? Due to the entropy of mixing, any tiny amount of impurity is highly favored entropically. This means that in general, you can get a small amount of a substance to mix into another. But take that too far, and th||8/21/2007||Free||View In iTunes|
||CleanLecture 20: Landau Theory of Phase Transitions; Oil, Water, and Alloys||Now that we know what order parameters are (see last lecture), we'll use the order parameter of a phase to construct the Landau free energy. The Landau free energy depends on the order parameter, and retains all the symmetries of the physical system. It's||8/21/2007||Free||View In iTunes|
||CleanLecture 19: Symmetries, Order Parameters, and the Failure of Reductionism||We finish the van der Waals equation of state, and use it to illustrate the liquid-gas phase transition. It turns out that at low pressure, the van der Waals equation of state has a wiggle where (dp/pV)0. Since this would cause an explosion, the system in||8/21/2007||Free||View In iTunes|
||CleanLecture 18: Van Der Waals and Geckos||We derive the shape of the phase boundary for solid to gas transitions (sublimation), examples being dry ice (CO2) or ice at low pressure. We derive the van der Waals equation of state, which is an improvement on the ideal gas equation pV=nRT. The ideal g||8/21/2007||Free||View In iTunes|
||CleanLecture 17: Introduction to Phase Transitions||We finish discussing chemical reactions, including how fast they progress, and what a catalyst can do for you. Then we begin a new topic: phases of matter and phase transitions between them. You've heard of solid, liquid, and gas, but did you know about t||8/20/2006||Free||View In iTunes|
||CleanLecture 16: Gibbs Free Energy and Chemical Reactions||We define the Gibbs Free Energy, which is the right energy function to use when you can control temperature, pressure, and particle number. This means chemists like it, because chemical reactions in a lab often take place under these conditions. We use th||8/20/2006||Free||View In iTunes|
||CleanLecture 15: Refrigerators and Path Dependence of Work||How refrigerators work. Why you can't cool your apartment by leaving the refrigerator door open. How heat and work depend on which path is taken. How to do completely meaningless work, the kind that's turned entirely into heat. We prove why the free energ||8/20/2006||Free||View In iTunes|
||CleanMidterm Review||We're having a midterm exam Wednesday, and today is a review of everything in chapters 1-7 in the text, Kittel and Kroemer's Thermal Physics. Topics include: Fundamental assumption of statistical mechanics, Laws of Thermodynamics, Probabilities and the Pa||8/20/2006||Free||View In iTunes|
||CleanLecture 14: Engines||Storytime with Thursday Next (Jasper Fforde), and her Uncle Mycroft's entropy-detecting entroposcope. Why are large-scale systems capable of producing irreversible processes (like glass breaking, or red and blue Kool-aid mixing), even though the microscop||8/20/2006||Free||View In iTunes|
||CleanLecture 13: Bose Condensates||More about Bose condensates. They're really weird -- at the lowest temperature, all bosons flock to the lowest available state, producing a "Bose condensate". Due to quantum mechanics, this is a remarkably stable state of matter, and is very hard to distu||8/20/2006||Free||View In iTunes|
||CleanLecture 12: Reversible and Irreversible Expansions||Now that we've derived absolutely everything about the ideal gas from scratch, it's time to do something useful with it! We'd like to eventually learn how to use this stuff to build engines and refrigerators. Today we discuss the basic processes (reversib||8/20/2006||Free||View In iTunes|
||CleanLecture 11: Bose Gas and Ideal Gas||Review of Fermions and Bosons. Review of Fermi Gas. All about the Bose gas, and its ditsrubution function. In the classical limit, the Fermi-Dirac distribution function and the Bose-Einstein distribution function approach the same form, and we recover ide||8/20/2006||Free||View In iTunes|
||CleanLecture 10: Fermi-Dirac Distribution Function||Why no two pieces of matter may occupy the same space at the same time. Fermions are antisocial; bosons are social. Bosonic examples: lasers and superfluid helium. All about Fermions. Fermions obey the Pauli exclusion principle, and each state may have ei||8/20/2006||Free||View In iTunes|
||CleanLecture 9: Gibbs Factor and Gibbs Sum||When the system and reservoir can trade particles, you can't use the Boltzmann factor and the partition function anymore. Instead, use the Gibbs factor, and the grand partition function (or Gibbs sum). We introduce these new things, and then apply them to||8/20/2006||Free||View In iTunes|
||CleanLecture 8: Chemical Potential||Introducing a new thermodynamically conjugate pair of variables: number of particles and chemical potential. Internal and external chemical potential. Voltmeters measure the total chemical potential. Great class brainstorm on internal voltages in your lif||8/20/2006||Free||View In iTunes|
||CleanLecture 7: Planck Blackbody Radiation||Deriving Planck's law of blackbody radiation. How to use it to tell the temperature of a star. Discussions about stars -- absorption lines and redshifts, and how to get the temperature correct anyway. Student demo of astronomy course software -- very cool||8/20/2006||Free||View In iTunes|
||CleanLecture 3: Entropy, Temperature, and the Laws of Thermodynamics||Fundamental assumption of statistical mechanics: all accessible states are equally likely. Ensemble averages are weighted averages. Two systems in thermal contact. How to define entropy and temperature. How to take partial derivatives. The laws of thermod||8/20/2006||Free||View In iTunes|
||CleanLecture 1: What is Statistical Mechanics and Why Does It Work?||Lightning fast review of quantum mechanics. Stationary quantum states, accessible states, fundamental assumptions of statistical mechanics. How to get from the microscopic quantum level to the macroscopic behavior you observe. We visualized atomic orbital||8/20/2006||Free||View In iTunes|
How to teach
An excellent bridge between statistics and chemistry. Will require, or motivate you to learn, calculus. For those interested in teaching per se, listen for the interactions; the pacing and organization of questions to students, and, especially, the timing, thoughtfulness, and tone of answers to student questions. The explications of the equations begin with motivating physical questions, but also with relations to previously learned math "technology" or similar laws. Even the individual variables are given re-introductions as needed, like minor characters in a long novel. This explanatory structure reminds me of really well-documented code. It applies a rudimentary narrative arc to terse facts. The tone, however, is consistently one of delight in discovery and respect for the cleverness, of, respectively, nature and science. You'll need calculus, including Taylor expansions and harmonic oscillators, as well as Kittel and Kroehmer's "Thermal Physics", 2nd ed., to actually master the subject, but, if you're homework-phobic, you can enjoy the lectures without the stress. When out in public, just remember to smile and nod.
Interesting and surprisingly accessible.
I have really enjoyed this podcast. The subject is very interesting, and Professor Carlson does an excellent job in explaining the physics behind the laws of thermodynamics. I say this as a person that has not studied any calculus -- I must admit that when the Professor turns to the equations I haven't a clue what's going on -- but the equations are bracketed by very clear explanations and examples. I'm looking forward to the next semester.
A good job ...
"Energies add and the total is conserved; probabilities multiply and the product is unchanged." - Edward Teller I joined the class late, what I knew about equilibrium statistical physics is contained in this quote from Teller’s book: “Conversations On the Dark Secrets of Physics” Teller was one of the great physicists of the 20th century, a man of his political circumstances and times. I personally did not agree with most of his politics, with one exception, not knowing very much about anything I agreed with his concern that most people are badly educated and taught only those few skills necessary to make some money and be fitted into “the economy” to serve. Teller clearly believes that some appreciation of complicated science can be taught to people without a lot of math. In Teller’s book you need only a little understanding of Calculus. Teller is having a conversation with his daughter Wendy and does his best to explain Physics. Wendy’s job is to ask questions and challenge her father to do better. If you like listening to Professor Carlson’s class she presents in a conversational style and does a good job explaining physics. I do not have the book that goes along with her course, I have “Thermal Physics” by Schroeder and an old paperback by Nash. Nash begins by stating: "Plus ça change, plus c'est la même chose. " I have been thinking about this statement for thirty four years but always part time and away from chasing dollars which occupies most of my clear head time.