Nothing to see here, folks
Meanwhile, we had a brief exchange on Twitter this morning, over a link which I’d sent him last week:
— askegg (@askegg) May 15, 2012
I asked which mark that was, and he replied with three points, the first of which was:
1) The universe may not actually permit absolutely nothing to exist
We had a little to-and-fro about necessity and contingency, with me saying that there’s no reason to think that the universe (or the quantum foam it arose from) was necessary (that is, that it couldn’t fail to exist). Andrew came up with this zinger:
@findo Sorry – no one has ever seen an example of absolutely nothing, so we cannot even say it is possible.
— askegg (@askegg) May 15, 2012
I said that this was logically incoherent, at which point he called me a troll and left the conversation -hence why I’ve decided to blog this: it’s a statement that merits some unpacking!
Why is it incoherent?
To begin with, it makes the fatal mistake of treating nothing as something. To even talk about observing nothing is as meaningless as talking about a square circle. So long as we have an observer (something) we cannot logically have nothing. You can’t observe nothing because, well… there’s not anything to be observed.
Perhaps even more interesting, however, is the way this statement goes well beyond the reaches of the kind of (positivist?) empiricism which Andrew espouses. It seems rather extreme to argue that we can’t even say that a state of affairs is possible unless we’ve actually observed it. That seems to conflate potential with actual in a very unhelpful way. What this statement appears to be saying, in fact, is because we observe things to exist, then things necessarily exist.
One of the reasons Andrew got annoyed seems to be because I maintained that his first point required a necessary universe to make any sense. He tried to say that we cannot posit, either way, whether the universe is necessary or contingent (though I would say that without reason to think it necessary, we’ve reason to think it to be contingent; cosmologists and physicist often talk about the ways in which the universe might have been different*, or failed to have existed).
Why does point 1 require a necessary universe?
We can’t have “nothing” and a universe, for they are mutually exclusive. If we have nothing, or rather, if we don’t have anything, then there is no universe to “permit” anything. If the universe is contingent (that is, it might have been otherwise, or failed to have existed) then there is no reason why, prior to the universe’s existence, no thing existed (leaving well alone the question of how something might come from no thing). The only way in which the universe could “not permit” a state of no thing existing is if the universe were an eternal and necessary entity.
Therefore, if the statement is to be supported, it requires a necessary universe, and it simply won’t do to then shy away and say “we don’t know”. Either support the statement, or drop it.
* Despite my reservations about the multi-verse hypothesis, and whether it achieves what it sets out to do, at the very least, that cosmologists and physicists can legitimately propose such a hypothesis, I think, shows that we’ve good reason to think it possible that the universe could have been otherwise. I don’t think Andrew is a fan of the theory, however, and by the logic of his argument here, without having observed any other universes, perhaps he’d argue we can’t even suggest they’re possible.