[harshavr]

Here's an attempt at distinguishing a truly quantum effect: can the same thing happen in a universe with classical physical laws and also keeping the other relevant variables fixed?(the latter part is important because the classical universe is, of course, turing complete).

Also, there is a similar programming qn. Suppose you have a program P running on a machine Q, and the api for a machine C is implemented on Q, so that programs for C can be run on Q. How do we actually figure out if P is really a C program running on Q?