Comment by raincole

8 months ago

BB(748) is a finite number, but I'd argue its magic also comes from infinites: the fact some Turing Machines run forever and never halt.

Is it? If it's not possible to prove that it's the best solution to bb(748), does it even exist in any meaningful way?

  • I'm not sure what you mean. First of all BB(n) is a function so it has value(s).

    And in theory we can prove BB(748)=X, where X is a plain big natural number, as long as we just assume ZFC is consistent. It's practically impossible, but not fundamentally impossible like proving Con(ZFC) in ZFC itself.

    • (Late Edit: the above comment was rather sloppy. I meant that we don't know if it's impossible to prove BB(748)=X in ZFC+Con(ZFC). It's not necessarily possible either. We just haven't ruled out the possibility.)