The Many Guises of the Second Law

Abstract: In 1824, the French engineer Sadi Carnot used inspired logical arguments to draw conclusions about the efficiencies of steam engines.   Today, we recognize Carnot’s conclusions as the original statement of the second law of thermodynamics – a powerful organizing principle for understanding the world around us.  In this talk I will take an informal excursion over the past two centuries, touching on a few of the second law’s various guises.  I will discuss, among other topics: how Carnot got the second law right, despite being clueless about the first law; why water boils at 95 degrees Celsius in Banff, and how this fact is explained by steam engine efficiencies; elbow room and the first Nobel Prize in Chemistry; and why erasing information requires work, even though writing information doesn’t.  The choice of topics is personal, not comprehensive.

Bio: Christopher Jarzynski received his AB degree from Princeton University (1987) and his PhD from the University of California, Berkeley (1994), both in Physics. After a postdoctoral fellowship at the Institute for Nuclear Theory in Seattle, he spent ten years in the Theoretical Division at Los Alamos National Laboratory, first as a postdoc and then as a technical staff member. In 2006 he moved to the University of Maryland, College Park. He is a Distinguished University Professor with appointments in the Department of Chemistry and Biochemistry, the Institute for Physical Science and Technology, and the Department of Physics.

Jarzynski’s research interests include theoretical and computational work at the interface of physics, chemistry and biology, with a particular focus on nonequilibrium phenomena and the application of thermodynamic principles to microscopic systems. In 1996 he derived an equality that relates irreversible work to equilibrium free energy differences, which has been verified in numerous experiments over the past two decades. His recent research focus includes quantum control and thermodynamics, the thermodynamic arrow of time, and the physical implications of information processing. His has received the Sackler Prize in the Physical Sciences (2005), the Lars Onsager Prize in theoretical statistical physics (2019), and a Guggenheim Fellowship (2020), among other awards.

He is a Fellow of the American Physical Society and an elected member of the American Academy of Arts and Sciences and the US National Academy of Sciences.

Zoom Meeting Link: https://uoft.me/Jarzynski2026
Zoom Meeting ID: 869 9225 6585
Passcode: Gordon2026

The Department of Chemistry is pleased to welcome Professor Christopher Jarzynski from the University of Maryland as our guest speaker for the 2025–2026 A.R. Gordon Distinguished Lecture Series. Professor Jarzynski will deliver three talks from April 15–17, 2026. Faculty members interested in a one-on-one meeting with Professor Jarzynski are invited to send requests to chem.reception@utoronto.ca. To learn more about the A.R. Gordon Distinguished Lecture Series, view a list of previous speakers or download a program for this symposium, click here.