A while back I noted an interesting paper about the arrow of time and memory loss in quantum mechanics. Unfortunately for that idea a new commentary by Jennings and Rudolph [PRL 104:148901, 2010] refutes it by exhibiting a counter-example.

## Convex analysis and thermodynamics

November 23, 2009A previous post briefly reviewed convex analysis. Here I’ll review the application of convexity in basic thermodynamics.

**Equilibrium states**

The concept of thermodynamic equilibrium is a generalization of mechanical equilibrium, where all forces and torques cancel each other. Informally, the idea is that a system in thermodynamic equilibrium has stable, unchanging macroscopic properties, which may be characterized by an n-tuple of extensive variables. Read the rest of this entry »