This is related to ergodicity. Thermodynamic states also re…
This is related to ergodicity. Thermodynamic states also return (arbitrarily close) to their starting position.
Replies
Both classical and quantum mechanics are ergodic and the evolution of a state can be represented as a kind of rotation in an abstract space. However, not every physical situation will return to its starting point within a finite time. In these cases, a full rotation doesn't really exist but we can connect ∞ to -∞ and imagine that it does.