The second law of thermodynamics is established by Clausius as the increase of entropy. The puzzle at the core of the second law is this: How can microscopic equations of motion that are symmetric with respect to time reversal give rise to macroscopic behavior that clearly does not share this symmetry? Because the rigid, prohibitive character of the second law emerges from the statistics of huge numbers, we might expect it to be enforced somewhat more leniently in systems with relatively few degrees of freedom.
In this talk, I’ll discuss several pieces of work that deal with the statistical fluctuations related to irreversibility at the nanoscale level. Outline for the talk:
1. Through the Jarzynski equality we’ll see how the equilibrium information is encoded in the microscopic response of a system driven far from equilibrium.
2. Through the Crooks fluctuation theorem, we’ll see symmetries lurk beneath the strong hysteresis that characterizes irreversible processes.
3. Relation between physical measures of dissipation and information-theoretic measures of time-asymmetry.
 Christopher Jarzynski. Annu. Rev. Condens. Matter Phys 2:329–51 (2010).
 Christopher Jarzynski. Phys. Rev. Lett. 78, 2690 (1997).
 Gavin E. Crooks. Phys. Rev. E, 60, 2721 (1999).