[tedsanders]

If the state evolution:

(a) is deterministic

(b) depends only on the current state, and

(c) can only occupy a finite number of states

then it will loop.

Pi digits do not satisfy this because while the digit space is finite (10), the next digit depends on more than just the prior digit.

Related (but not the same): https://en.wikipedia.org/wiki/Poincaré_recurrence_theorem

[bobsmooth]

The speed of the balls are changed by a small random amount when they hit a tile, so it's not deterministic.

[Scarblac]

If it's a deterministic RNG then it just means the state space is very large.

[BriggyDwiggs42]

Ooh that’s cool I’ve never seen that before.