I believe whether there is a deterministic system underlying quantum behavior is still an open question. My suspicion is that nothing can produce true randomnes

I believe whether there is a deterministic system underlying quantum behavior is still an open question. My suspicion is that nothing can produce true randomness, in whioh case Turing machines are incomplete only for nonexistent computations. If I'm wrong, Turing machines still feel the effects of true randomness at a greater degree than the brain (compare the size of an axon with silicon), though my assumption that everything in the universe can be modeled in a computer falls through.