I agree, there are necessarily some background facts that must be consistent with the environment. Science might eventually be able to trace the trajectory of the asteroid that killed off the dinosaurs, but that doesn't necessarily mean you would need to simulate every asteroid in the solar system since its initial formation.

The amount of information science could infer on many questions is strictly bounded and in those cases we could only reason stochastically. The data presented at time of first observation can then be generated randomly from the set of answers consistent with what's already known.