So here is the argument on the universe cooling down

Assume no entry nor exit.

We have the aggregate of equal tings in kinetic energy, so they have coffee cup slosh now and then. The slosh moment create a Markov level up, a bi of sustained momentum each time the slosh happens.  The process continues up the dimensionality, each time spotting a symmetry in kinetic energy, harvesting it, and dropping back to the nearest three Markov nodes. We do not cool down, we get complex, we get geodesic on a massive scale. But we reach a limit, and just get stuck, a frozen crystal of vacuum.