chapotraphouse

Poincare recurrence is, as far as we understand the laws of the universe, totally possible. If you think of the set of possible states of the universe, the current state it's in is necessarily in that set. Then, because it's a closed system, it necessarily has to come back to that state eventually. The hard part to grasp of how that's physically possible is that, of course, classical thermodynamics tells us that there's an arrow of time that points in the direction of increasing entropy. But looking at statistical thermodynamics, it turns out that it's only the case that it's overwhelmingly more likely that a system, in the macro scale, goes in the direction of increasing entropy. A system spontaneously becoming more ordered is possible, just so very unlikely that it will take a completely unimaginable amount of time to happen. Heat death could reverse itself and little by little build up into a new big bang after silly amounts of time. Like, Tree(Graham's Number) silly.