Physics 328, Autumn 2021


Marcel den Nijs

Office: PAB B429
Department of Physics
University of Washington
Seattle, WA 98195

10:30 am-11:20 am
Mo, We, Fr
Hybrid format
using Zoom when online
in PAA A110 when in-person


This is the senior level Physics UW undergraduate course in Statistical Mechanics and Thermodynamics.

Thermodynamics is the macroscopic formalism that describes systems with very-many degrees of freedom. Thermodynamics originated from empirical observations. Statistical mechanics bridges the gap between the macroscopic and the microscopic descriptions of such large collections of particles. It explains the laws of thermodynamics and describes the fluctuations that appear when the number of degrees of freedom is smaller, ranging from Brownian motion, still visible by eye, to nano-length scale phenomena such as molecular motor transport at the biological cell level.

Quantum statistical mechanics appeared early in the 20th century and is one of the corner stones of solid state physics, as well as particle and nuclear physics. In this course we will be able to cover only basic quantum phenomena, such as Bose-Einstein and Fermi-Dirac statistics, the vibrational and electronic contributions to the specific heat of solids like metals, and Bose-Einstein condensation in gases and liquids (Helium-4).

Statistical mechanics was originally developed on the classical mechanical level by Boltzmann, Maxwell, and others, to describe for example dilute gasses like air. Many current fluctuating phenomena are intrinsically classical again, e.g., the motion of molecular motors in biological physics, most critical phenomena and phase transitions, complex networks in neural science and the internet. This means that various fundamental statistics issues are back in focus again, e.g, the Gibbs paradox can not be dismissed anymore by referring to quantum indistinguishability.



The lectures will be presented in hybrid form, partially online by Zoom, and partially in-person in PAA A110. The details will be listed on Canvas on the "day-by-day" page, will will depend on how the Covid-19 situation evolves this Fall. The Zoom link will be posted on Canvas. The first lecture will be in-person.

All homework assignments and solutions, quiz solutions, and all other electronic communications for this course will be posted on the Canvas Course site.


Office hours by Zoom every Tuesday from 2pm-3pm. Please Email me for personal communications and also for all other questions and/or for special Zoom meeting requests.


To qualify for credit you must:
  • Work-out by yourself and/or in small groups all weekly homework assignments and upload your work on Canvas before the Monday afternoon due dates.
  • Participate in every weekly 15 minute short-quiz, during-class on Wednesdays, and upload your work on Canvas. You participate in-person (when we meet in A110 that day) or by Zoom. These quizzes are direct follow-ups of the homework assignments completed that week.
  • Participate in the final exam. Whether the final exam is in person or online will be decided during the quarter.
  • No midterm is planned at this moment. The short quizzes take that role.
The course grade will depend mostly on those short quizzes and the final. Homework credit will focus on effort and completeness.

The details of the above will be explained during class. Changes might be needed during the quarter depending on how the Covid situation evolves. Such changes will be discussed in class and posted on Canvas.


Online tests pose a challenge for evaluating "knowledge". They are unavoidably to be treated as open book (and open to the world) exams. The short in-class Wednesday quizzes are very short and presume intrinsic knowledge of the homework assignment due the previous Monday, for which solutions will be posted on Canvas that same Monday late afternoon. The office hours on Tuesday provide you the opportunity to clarify questions about that material, before the short test on Wednesday. The short tests are meant to be too short and too dense to meaningfully consult the "wide open world." The first test is for practice and needs to be uploaded (at your leisure) during the first week to avoid logistics surprises later on.


According to UW rules everybody must be fully vaccinated for Covid and wear masks at all times when meeting in-person.

Students who require SPECIAL ACCOMMODATIONS or encounter special (un)expected circumstances during the quarter should contact me as early as possible, so we can address these in a timely fashion (before the next short test). See also: Disability Resources for Students .

The RELIGIOUS ACCOMMODATIONS policies of the UW can be found here:
The background picture on this WEB page shows the so-called Fountain Effect in Super Fluid Helium. The picture on-top shows a domain wall trapped on a growing crystal surface with Ising type surface reconstruction ordering.

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