I often think about problems that require an understanding of the very essence of computation and its inherent limitations. So, my questions are as followed:

* Is the universe isomorphic to a universal turing machine?
* Is the universe isomorphic to a universal quantum computer?
* What evidence do we have within our universe to support an answer to such a question?
* What corollaries follow from a universe that is or is not isomorphic to a universal turing machine (or universal quantum turing machine)?
* Is this question really answerable, and what is the current literature on this subject?

I'm mostly interested in the implications and corollaries that follow from a universe that is or is not isomorphic to a turing machine (or universal quantum computer) and the insights that it would provide us with, about the nature of computation.