Thermodynamic Irreversibility

A pure state happens when we know all there is to be known about it. When two objects are entangled, you can't fully specify one of them without knowing everything about the other too. Marletto says their conjecture is that thermo dynamic irreversability might stem from this. The information in the pure state gets spread out by entanglement and is hard to recover. It's like trying to reform a droplet of ink once it's dispersed in water.