Thermodynamics is a major part of modern physics, which Einstein famously said “will never be overthrown within the frame of applicability of its basic concepts”. Statistical Mechanics is widely thought to provide an underpinning to Thermodynamics, explaining the thermodynamic behavior of physical systems in terms of their microscopic constituents. However, each of these theories still has its own foundational problems:

What exactly is thermal equilibrium? What do we mean by reversible/irreversible processes? And what exactly is the Second Law, given that there are so many formulations of it? In what way do the Boltzmannian and Gibbsian accounts of statistical mechanics lead to different predictions? Under what conditions does a thermodynamic limit exist, and when do they fail?

These questions lead us far beyond the classical systems (mostly gases) envisaged by Carnot, Clausius, or Kelvin. Long-range forces invalidate the notion of a thermodynamic limit, and in condensed matter systems lead us to topological quantum order, edge states, and quantum phase transitions. In gravitational systems - where statistical mechanics and thermodynamics have to be done very differently anyway - one gets black holes, event horizons behind which information disappears, and a thermodynamics associated with a Hawking temperature, in which the connection with statistical physics and entropy production is quite unclear.

At the level of the entire universe one has a cosmic arrow of time whose connection with the thermodynamic arrow is still obscure. Statistical mechanics is applied even at the scale of nanosystems and nuclei; how justified is this? And how do we deal with conditions far from equilibrium (as in, eg., most astrophysical systems) or the fact that highly organized systems develop under these conditions, in defiance of the 2nd law?

This symposium will discuss such questions from a variety of perspectives, bringing together historians and philosophers of physics, as well as theoretical and experimental physicists.

Program and participants

1.   History of Thermodynamics and Statistical Physics 

•  Jos Uffink (Minnesota)

•  John Norton (Pittsburgh)

2.   Philosophical Issues in the Foundations of Statistical Physics 

•  David Wallace (Pittsburgh)

•  Roman Frigg (London School of Economics)

3.   Statistical Mechanics for Infinite Systems: Phase Transitions and Longe-range Interactions

•  Patricia Palacios (Salzburg)

•  David Lavis (King's College London)

4.   Quantum Phase Transitions

•  Rahul Nandkishore (Colorado) 

•  Bert Halperin (Harvard)

5.   Black Hole Thermodynamics

•  Robert Wald (Chicago)

•  Juan Maldacena (IAS, Princeton)