The conversation turned to the planetary model of the atom. Imagine there are cosmic megagiants studying the Solar system. What kind of a model would they develop - a deterministic or nondeterministic?
The solar system is as inperceptible to their senses as the atom is to our senses. Perhaps they will bombard and examine how the projectiles are scattered, like in the Rutherford's experiment. In principle, this would allow the giants to detect orbital regularities if the projectiles can be thrown sufficiently frequently. On the other hand each projectile big enough for them to track will cause orbital perturbations, complicating the analysis.
Furthermore, assume that for these megagiants it is physically impossible to throw their projectiles more often than once in 50 Myr. Planetary orbits become mildly chaotic over such long periods of time even without the external perturbations, and their experiments will include significant statistical uncertainty. In all probability, their theory of the "Solar systems" will be as indeterministic and statistical as our own theory of the atom. Such a theory would be wrong or incomplete, but not to these giants, who are constrained by the limitations of their own nature. Their best theory would be the accurate theory of these limitations rather than the true theory of the Solar system.
Then I had an uneasy thought about the dinosaurs...
I hope there are no cosmic giants developing a quantum theory of the Solar system!