Thermodynamics and statistical mechanics
Posted by Arjendu on July 19, 2014
This fall I will be teaching Carleton’s junior level thermal/statistical physics course. It’s an annually offered course and for various reasons has been one of the courses furthest from equilibrium in our Department. That is, it has always been at least partly or fully required (let’s not get into how we manage to partly require something, that’s a whole different story) but its format, placement in the curriculum, instructor, syllabus: all of those state variables have fluctuated greatly since I came to Carleton.
The topic itself allows for such a wide variety of interpretations and paths. Looking at its place in the curriculum, the possible uses to which this knowledge will be put in future classes or professions, my sense of the course is that it must follow and connect both the macroscopic empirical approach of thermal physics and the microscopic bottom-up approach of stat mech. And also, even though I’ve mainly been presented this material as a ‘methods + models’ theory course, it’s increasingly clear to me that it must include some real world considerations (such as energy efficiencies, etc).
So — as I return to the Carleton classroom after 4 years away — the questions I have been brooding over include: How should I teach it? What should what path do I take? I’ve taught it once before but that was seven years ago, and I’m definitely starting from scratch in building a syllabus, and that almost always comes down to selecting a text. All this apart from format — how much lecture versus discussion? what kinds of open-ended problems, and when?
Here’s where I stand: I have personally been lead through some wonderful treatments (the Kittel and Kroemer version as a 3rd year student at St. Stephen’s College with the great Dr. Popli was where I had the most fun, and I am familiar with paths through Reif, Pathria, etc, etc). I also spent about 5 years as part of the Center for Statistical Mechanics at Austin though my own research has intersected with statistical mechanics on rather abstract issues about the behavior of entropy and signatures of chaos and irreversibility and decoherence, etc. If anything, as a (semi-)specialist, it is harder to gauge what topics should be considered absolutely necessary, and I am less clear about what is intuitive (I don’t remember the bliss of my ignorance that well anymore!), what the right pace is for going over fundamental laws versus doing applications, etc, etc.
In the last few weeks I have been reading/skimming multiple textbooks, reading up on approaches, getting a sense of pace. My short-list for texts — and it’s likely all three books will remain open on my desk for the next few months — are Kittel and Kroemer (‘Thermal Physics’), Schroeder (‘Introduction to thermal physics’), and Stowe (‘An Introduction to Thermodynamics and Statistical Mechanics’). Whichever I go with, it’s going to be a close call and the choice depends — whether I like it or not — as much on things like what works best as the core for my 9.5 week term, and where Carleton students are in particular, as on the approach. Despite K+K’s name, it’s really much more stat-mechy in its approach, which is both where I am happiest and also what I am trying to avoid. Both Schroeder and Stowe weave stat mech and thermo together, and I think the integration is more seamless but also idiosyncratic in Stowe. I have also considered doing one book as the core text and another as supplemental reading, but that’s rather unlikely.
Something I like to do when brooding over a course like this is to find a good layperson’s treatment first if possible, to remind me what it’s all about, and to broaden my vocabulary for connecting equations and intuitions. I picked up Peter Atkins’s slim 100-page treatment (“The Laws of Thermodynamics: A Very Short Introduction”) and got through 3/4 of it while on idle during some parentally required down time. I’d recommend it to anyone looking for an excellent stripping down of thermodynamics and statistical mechanics to the absolute basics. He moves between the microscopic and the macroscopic very nicely. And his chemists perspective is really helpful for me in ‘keeping it real’.
The ideas, rules, and relationships of this area are among the most subtle and counter-intuitive and yet foundational. What’s more foundational than the Second Law, about which Einstein said: “It is the only physical theory of universal content, which I am convinced, that within the framework of applicability of its basic concepts will never be overthrown” ? And yet one bumps into these ideas when thinking about day-to-day issues such as engines and work and chemical reactions.
It should be an interesting fall, particularly given that I will be doing an Argument and Inquiry Seminar on energy issues at the same time.