I'm sorry but WTF.

Maybe I have my computer science theory all wrong but I distinctly remember this statement: the universe is Turing complete.

That means that it is at least a computer - it may be something more - but it must be at the very least a computer.

Secondly WTF is with non-computable arguments. Given arbitrary memory and ability to do computation - anything can be computed.

Thirdly what's this mapping crap - the universe's probabilistic state does not need to be mapped - it's just information moving around.

The Lagrangian method he uses can be computed. Looks just like an expensive optimisation problem.