> "Sma," the ship said finally, with a hint of what might have been frustration in its voice, "I'm the smartest thing for a hundred light years radius, and by a factor of about a million ... but even I can't predict where a snooker ball's going to end up after more than six collisions."
[GCU Arbitrary in "The State of the Art"]
6? That can't be right. I don't know how big a GCU is, so the scale could be up to 1 OOM off, but a full redirection of all simulation capacity should let it integrate out further than that.
For ball-to-ball collisions, 6 is already a highly conservative estimate-- this is basically a chaotic system (outcome after a few iterations, while deterministic, is extremely sensitive to exact starting conditions).
The error scales up exponentially with the number of (ball-to-ball) collisions.
So if the initial ball position is off by "half a pixel" (=> always non-zero) this gets amplified extremely quickly.
Your intuition about the problem is probably distorted by considering/having experienced (less sensitive) ball/wall collisions.
> "Sma," the ship said finally, with a hint of what might have been frustration in its voice, "I'm the smartest thing for a hundred light years radius, and by a factor of about a million ... but even I can't predict where a snooker ball's going to end up after more than six collisions." [GCU Arbitrary in "The State of the Art"]