I mean that in order for the universe to be in a heat death state, that universe needs to be in thermodynamic equilibrium. You don’t get that merely from the first and second laws.
For instance, the universe could expand. If it expands fast enough, the entropy associated with the heat death state could rise faster than its own entropy can increase, kicking it out of heat death. That’s what I mean by needing a cosmological assumption.
I mean that in order for the universe to be in a heat death state, that universe needs to be in thermodynamic equilibrium. You don’t get that merely from the first and second laws.
For instance, the universe could expand. If it expands fast enough, the entropy associated with the heat death state could rise faster than its own entropy can increase, kicking it out of heat death. That’s what I mean by needing a cosmological assumption.