They aren’t asserting that the whole universe, including the unreachable portion, is finite in extent with certainty. They’re just saying that it’s possible, and they also note infinite is possible too in the sentence after which that footnote follows.
Even if you think a universe with infinite spatial extent is very unlikely, you should still be entertaining the possibility. If there’s a chance it’s infinite and you can have infinite impact (before renormalizing), a risk neutral expected value reasoner should wager on that.
FWIW, I’m sympathetic to their arguments in that section against expected value maximization, or that at least undermine the arguments for it. I’m not totally convinced of expected value maximization myself.
However, that doesn’t give a positive case for ignoring these infinities. I find infinite acausal impacts not too unlikely, personally, because both that acausal influence is possible seems more likely than not and that the universe is infinite in spatial extent (and in the right way to be influenced infinitely acausally) seems not too unlikely.
They aren’t asserting that the whole universe, including the unreachable portion, is finite in extent with certainty. They’re just saying that it’s possible, and they also note infinite is possible too in the sentence after which that footnote follows.
Even if you think a universe with infinite spatial extent is very unlikely, you should still be entertaining the possibility. If there’s a chance it’s infinite and you can have infinite impact (before renormalizing), a risk neutral expected value reasoner should wager on that.
FWIW, I’m sympathetic to their arguments in that section against expected value maximization, or that at least undermine the arguments for it. I’m not totally convinced of expected value maximization myself.
However, that doesn’t give a positive case for ignoring these infinities. I find infinite acausal impacts not too unlikely, personally, because both that acausal influence is possible seems more likely than not and that the universe is infinite in spatial extent (and in the right way to be influenced infinitely acausally) seems not too unlikely.
But I am optimistic about renormalization.