> My guess: because the abstract double pendulum is a model that only approximates real double pendulums. This subject is somewhat outside of my area of knowle

> My guess: because the abstract double pendulum is a model that only approximates real double pendulums. This subject is somewhat outside of my area of knowledge, but if I had to guess, this is what resolves the paradox. An abstract mathematical chaotic system is different than a real-life one, and it is my guess that if we performed the experiment, we would find the orbits would be different. QM has withstood every test thrown at it so far, and while it's always possible that a correction to it will be found, I think it will be a very rare event should it happen.