#P is still decidable by Turing machines. And, I’m pretty sure that #BQP is too. (Just with a large slowdown.) Now, yes, there are models of computation whic

#P is still decidable by Turing machines. And, I’m pretty sure that #BQP is too. (Just with a large slowdown.) Now, yes, there are models of computation which cannot be simulated by a Turing machine, but I don’t know of any substantial evidence that a physical process uncomputable. Any computation which has a finite number of possible inputs is computable, using a lookup table, and therefore using a Turing machine. So, for any physical process to be uncomputable, it must be such that there are infinitely many possible states of it, for it to proceed from. And, the Bekenstein bound, if correct, would seem to suggest that no structure like that can exist within a bounded region of space.