> it's nevertheless true that physical computers cannot simulate all Turing machines Right, I wasn’t arguing that physical computers can be Turing machines, bu

> it's nevertheless true that physical computers cannot simulate all Turing machines Right, I wasn’t arguing that physical computers can be Turing machines, but instead that sets of operations can be Turing complete. There are sets of operations with which one can compose a program that perfectly simulates a Turing machine. The problem is that physical computers cannot always run these programs accurately, due to memory constraints. But the set of operations is itself Turing complete.