Comment by lmm
11 years ago
You don't just wait, you prove that they all don't halt. There are only finitely many of them. You can't provide a general algorithm for proving that Turing machines don't halt, each one is going to require a special case - but it will be a fact that the physical instance of the machine halts or doesn't halt. (Or if it halts in some models of ZFC but not others, that would be even more interesting).
There won't always be a proof. If there always was, you could programmatically find it via brute-force search and solve the halting problem.