In The Multiverse & You (& You & You & You…), Sam Harris talks about multiverses with Max 'Mad Max' Tegmark. Sadly, Harris didn't take the opportunity to ask Tegmark about his foundation, Foundational Questions Institute (FQXi), being funded by Templeton. To be fair, the FQXi website has a page on their finance arrangements which make huge efforts to distance the Institute from their financiers. Even so, they are playing with Templeton money which is always disappointing when proper science is involved.
But this is about multiverses. In their discussion Harris and Tegmark (although possibly more so Harris) make much about the idea that if there is a multiverse, noting that they only got to Level 2 Multiverses, then there will be an infinite number of Harrises and Tegmarks doing slightly different versions of the podcast. At one point the googolplex is mentioned, a number which although not infinite is officially considered to be very big - 10 to the power of 10100. Apparently, someone worked out that the number of possible arrangements of the original particles in the universe is in the order of a googolplex. Not quite infinity but, you know, a lot. The idea is that out of those arrangements, even if a relatively small fraction of them would result in us, that would still be a lot of arrangements with beings indistinguishable from us in them.
Take that one step further and say there is the possibility that there were more or fewer particles in the initial arrangement of the universe, then you get a huge number of googolplexes of possibilities. Within that suite of possibilities, there would again be a lot of arrangements with beings indistinguishable from us in them. Then there's the possibility of duplication - which brings us to the possibility of an infinite number of replications of us in existence. There might not only be an infinite number of universes which are very, very similar to our own, but also an infinite number of universes (albeit a "smaller infinity") that are exactly the same.
So, it's true enough that, if Tegmark is correct about multiverses, that there are an infinite number of Tegmarks and Harrises who has a discussion that was turned into a podcast. And it's true that there is an infinite number of Tegmarks and Harrises who had very similar, but slightly different, discussions that either did or didn't get turned into a podcast. And it's true that this infinity of variations might include discussions in which Harris suddenly began talking in Hungarian.
What concerns me, however, is that either by accident or design, the presentation of multiverses was staggeringly arrogant. They failed to mention that there was an infinite number of universes in which their discussion didn't take place even within the infinite number of universes which contain a Max Tegmark and a Sam Harris. It's a bit like a series of matryoshka dolls, each of which is infinite in size but, because the rubberiness of infinity, can be ranked:
The infinite number of universes in which the Harris-Tegmark discussion happened precisely as it did in ours which is a subset of:
The infinite number of universes in which the Harris-Tegmark discussion took place which is a subset of:
The infinite number of universes in which Harris and Tegmark met each other which is a subset of:
The infinite number of universes in which both Harris and Tegmark exist which is a subset of:
The infinite number of universes in which humans exist which is a subset of:
The infinite number of universes in which intelligent life is possible which is a subset of:
The infinite number of universes in which there is something rather than nothing:
The infinite number of possible universes.
Tegmark himself points out that human endeavours have been plagued by a sense of arrogance – this, our village, is the only village. No? But this land is the only land. No? But this continent is the only continent. No? But this planet is the only planet. No? But this solar system is the only solar system. No? But this galaxy is the only galaxy. No? Well, the universe that we can see is certainly the only universe. Perhaps we’ll soon be trying on “this is the only multiverse” for size.
The arrogance is inherent in the contemplation of what we are doing (right now) and the imagining of what would be changed if things were very slightly different, as if our activities were some sort of focal point for the universe.
But I think it gets a bit worse, as least in so far as the discussion that Harris and Tegmark actually did have, in our universe. They were discussing how there could arguably be an infinite number of universes such that anything that is possible does actually happen. Think about that for a moment. Anything that is possible happens in some universe or another. Really?
Is there a universe in which an analogue of me (clearly not actually me, because I live in this universe, but a version of me that would think precisely the same as me except that this other version …) buys a lottery ticket every week and wins the jackpot every time? This is very highly unlikely, to be sure, but it's not strictly impossible. Oh Grand Pixie, why oh why am I not that version of me?
It gets worse. Harris and Tegmark touch on how the brain (and the suite of the processes within the brain) interacts with the outside world, implying that the common ground is mathematics. My concern isn't so much with that, but with the concept that there are things go on inside our brains that are interpreted as interactions with an external world that really aren't. Usually these are minor hiccups and most of us resolve them and carry on. Some however are constantly plagued by voices in their heads and other delusions. It's highly unlikely that we could all be affected by chemical states in our neurology that results in coherent voices that all tell us that a god is real. But it's not strictly impossible. And it's not strictly impossible that cloud formations could take on the appearance of an old man in the sky (or an old woman in slightly less politically incorrect alternate universes).
What I'm suggesting here is that, at least in the rather light touch on multiverses discussed by Harris and Tegmark, the odds are that in some universe there will be all the evidence that anyone could ever need to prove the existence of a god. The vast majority of prayers would be answered in such a universe (merely on the basis of coincidence, but the supplicants don't know that). Everyone would get visitations from what appear to be divine agents (or rather have internally generated experiences of such visitations, purely due to random chemical reactions in their brains).
Remember that we are talking about infinity here, not just a very big number. Even if the likelihood of an apparently god-infested universe is infinitesimally remote, if there is an infinite number of universes, then there is at least one universe like that, and possibly even an infinite number of them.
Would Harris and Tegmark agree with this, as a possibility?
Either way, it seems that multiverse predictions do tell us something about the likelihood of there being a god.
Consider the difference between 1) a great being which exists and for whose existence there is clear evidence and 2) another great being for which there is no compelling evidence of its existence. Which is the greatest? Unless hiddenness is defined as a strength (which seems unlikely since we are repeatedly told that the god of the theists wants to have a relationship with us), the evidence based god is superior. Some theists will argue that it's not possible to have evidence of their god. But what multiverse theory seems to be telling us is that it actually is possible to have overwhelming evidence of a god, even their specific god, and that that applies even if such a god does not exist. But clearly you and I don't live in a universe in which there is overwhelming evidence of anything of the sort.
On the contrary, we live in one of the universes in which it is not only possible but entirely reasonable to reject the notion of a god. The question therefore is this: How do theists who buy into multiverses and subscribe to some sort of mandatory divine hiddenness get around this issue?