Fluctuation theorem says that there will be fluctuations in microscopic scale that results local decreases in entropy even in isolated systems. According to the Poincaré recurrence theorem, after sufficiently long time, any finite system can turn into a state which is very close to its initial state. It means second law of thermodynamics will be broken in even macroscopic scale.(adsbygoogle = window.adsbygoogle || []).push({});

We can always observe fluctuations in non-equilibrium systems, however, my question is; If a system eventually reaches to the maximum entropy state (everything is in absolute equilibrium), then do we expect fluctuations even in that state? Or after reaching maximum entropy, the system will remain same always or not? In other words, does Poincaré recurrence theorem valid for systems with maximum possible entropy?

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# Poincaré recurrence and maximum entropy

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