Re: reasoning under computational limitations

Nick Bostrom (
Mon, 5 Apr 1999 19:36:35 +0000

Wei Dai wrote:

> On Sun, Apr 04, 1999 at 09:25:11PM -0700, wrote:
> > But isn't the conventional model of the universe, if we assume that it
> > is spatially open and unbounded, in exactly this form?
> The conventional model does have a prefered position, namely the Big
> Bang.

The Big Bang is a singularity but not really a position. Immediately after the Big Bang, if the universe is open or flat, the universe was spatially infinite. So if you assign number 1 to the Big Bang, what spacetime point is number 2?

> > Would you suggest that, on philosophical grounds, we have evidence that
> > the universe cannot be infinite (without preferred positions)?
> Yes.

What are these grounds? (You referred to "various paradoxes"--which ones do you have in mind?)

Nick Bostrom Department of Philosophy, Logic and Scientific Method London School of Economics