Scientists have long known the ins and outs of equilibrium thermodynamics. Systems in equilibrium — a stable state of unchanging balance — are governed by a neat set of rules, making them predictable ...

How it works: the wave in the foreground is an illustration of the phase of an out-of-equilibrium Bose-Einstein condensate in a 1D cavity, which belongs to the Kardar-Parisi-Zhang universality class.