Actually, when we assume that any particular physical system is computable, that's exactly what it is - an assumption, there is currently no strong evidence tha

Actually, when we assume that any particular physical system is computable, that's exactly what it is - an assumption, there is currently no strong evidence that all physical systems are computable, and despite the fact that it seems most people (including experts) believe that they are, it's still usually considered an open question. > Viewed from the right angle, the CTD Principle still is shocking. All we have to do is look at it anew. How odd that there is a single physical system – albeit, an idealized system, with unbounded memory – which can be used to simulate any other system in the Universe! http://michaelnielsen.org/blog/interesting-problems-the-church-turing-deutsch-principle/ http://michaelnielsen.org/blog/interesting-problems-the-chur...