Thursday, 22 September 2016

Chance or Design?

In Barnes' Objections to Fine-Tuning, I concluded that there are only two fundamental responses to claims fine-tuning, that fine-tuning (and/or the appearance of fine-tuning) is due to chance or that fine-tuning (and/or the appearance of fine-tuning) is due to design, since the other options inevitably collapse down to chance or design.

We should perhaps revisit Barnes' "11 objections" in light of this:

Chance: It’s just a coincidence

Chance (overlaid by an appeal to ignorance): We’ve only observed one universe, and it’s got life. So as far as we know, the probability that a universe will support life is one out of one!

Chance/Design: However the universe was configured, evolution would have eventually found a way

Chance/Design (with another appeal to ignorance): There could be other forms of life

Chance/Design: It’s impossible for life to observe a universe not fine-tuned for life

Chance/Design: Maybe there are deeper laws; the universe must be this way, even though it looks like it could be other ways

Chance: Maybe there are bajillions of universes, and we happen to be in one of the few that supports life

Design: Maybe a physics student in another universe created our universe in an attempt to design a universe that would evolve intelligent life

Chance: This universe with intelligent life is just as unlikely as any other universe, so what’s the big deal?

Chance: The universe doesn’t look like it was designed for life, but rather for empty space or maybe black holes

Design: Fine-tuning shows there must be an intelligent designer beyond physical reality that tuned the universe so it would produce intelligent life

I have left a few of them as undetermined, Chance/Design because, at the end of the day, these "objections" don't really distinguish between the two fundamental options.  For example, while "(no matter how) the universe was configured, evolution would have eventually found a way" implies an end goal (intelligent life) that evolution is "trying" to achieve, there's nothing inherent to the argument that prefers (cosmic) evolution being designed to find intelligent life over (cosmic) evolution simply stumbling upon it.  The latter sort of relies on our knowledge that intelligent life is - at the very least - possible in one possible sort of universe, even if it may be improbable and the implication is that, given enough time and/or space, (cosmic) evolution would therefore eventually lead to intelligent life.

The main problem, the problem that theists want us all to come unstuck over, is that the fine-tuning of our universe for intelligent life does appear to be highly improbable.  We are supposed to throw up our hands and say "It's so unlikely that this should have happened by chance, so it must have happened by design.  Therefore, god."

It's for this reason that the multiverse is disliked by some theists, the multiverse short-circuits the theistic fine-tuning argument, because if there are an infinite (or sufficiently large) number of universes, with random tunings, then it becomes a lot more likely that some of them will be tuned sufficiently well for intelligent life.  If there are universes without end, a potential infinity of them, and it is possible that a universe may be tuned for intelligent life (which we know to be so), then it becomes statistically certain that there will be universes in which intelligent life arises - so such a universe existing becomes unsurprising and its existence cannot be counted as evidence for design.

Note that a universe with intelligent life is not evidence against design in and of itself but, given a claim with respect to a particular type of designer, a particular type of universe can be evidence against that designer (hence the problem of evil and the existence of vagueists, theists who strip away anything and everything associated with their god that might permit it to be falsified).

Barnes' list does have a multiverse related "objection" to fine-tuning: "Maybe there are bajillions of universes, and we happen to be in one of the few that supports life".  This is a somewhat flippant way to describe the multiverse, but they seem to be Luke Muehlhauser's words, not Luke Barnes'.  In the Pale Blue Dot podcast that Barnes appeared on, he confirms that we don't necessarily need an infinite number of universes, merely "enough" to make the supporting of life, somewhere - in one of those universes, likely.

This is part wriggle and part lure.  It seems reasonable to answer the argument that this universe is highly unlikely with one that, while not certain, nevertheless is likely.  However, the theists have a philosophical argument to the effect that their god is not only likely, but necessary.  In their minds, it doesn't matter if our universe is likely on a naturalistic assumption, given the multiverse - because they have the universe being the necessary product of a necessary being.  (It doesn't seem to matter to them that their necessity arguments have holes in them large enough to fit a few multiverses - they still have an argument.)  The lure involves encouraging those thinking about multiverses to satisfy themselves with a less than infinite number of universes (even a less than ridiculously huge, but not infinite, number of universes).  It's more of a rhetorical trick than anything else since the equations will tell us how many universes fall out of a multiverse theory, not any desire to explain fine-tuning.

Rather strangely, when discussing the multiverse with Muehlhauser, Barnes doesn't start with any of the scientific theoretical models that lead to a multiverse, like Guth's eternally inflationary multiverse, or string theory.  No, he starts with a couple of philosophical multiverse - although he does express bafflement at them.  Perhaps, we could think he's just dispensing with the nonsense first.  But no.

Directly after mentioning (and mischaracterising) eternal inflation, he leaps into typicality and Boltzmann brains.  Now I know that some well-educated, apparently sane and respected people do apparently take Boltzmann brains seriously, but I don't.  Briefly, the idea is that random fluctuations in thermal equilibriums, given enough time and space, will sometimes create a "brain", which I interpret to be little more than a nexus of something or other that is (or becomes) conscious, but is not necessarily encased in walnut like globs of flesh.  These could fluctuate into existence with a complete history in place and, albeit briefly, it would be impossible to distinguish between the existential experience of these Boltzmann brains, and that of our brains.

Furthermore, the argument goes, these fluctuations would be far more common (due to entropy considerations) than instances in which brains like ours evolve out of some primordial soup over a period of three to four billion years.  So, if this were true, the fact (if it indeed is a fact) that we humans have the nature that we have rather than being Boltzmann brains would be very unlikely.  We'd be very untypical of intelligent beings in general, since most of them would be fluctuations that dissipate soon after coming into existence.

I think this is a nonsense argument for the basically the same reason that, although it is theoretically possible in quantum physics for someone to spontaneously teleport from one spot to another, spontaneous quantum teleportation of humans will never happen.  The fluctuation required for an intelligence (even one as humble as my own) to come into existence and have pre-loaded experience is extremely specific - it's very highly ordered, which means that it's very low entropy (it's also very "surprising" but more of that in a later post).  I would consider the fluctuation of this intelligence into existence, pre-packaged with experience and awareness, without the slow grind of evolution behind it to be sufficiently astonishing as to be miraculous.

What I observe, as inherent to the Boltzmann brain argument, is an effect that I'd like to term "inconsistent poverty of imagination".  The theist is willing, when confronted with the idea of a multiverse, to imagine all sorts of nonsense and then place what we know to exist (intelligence based on evolution from very humble beginnings) on a par with the nonsense that they just thought up (intelligence based on thermodynamic fluctuations in some high entropy region of a universe or multiverse), but when asked to imagine alternatives to their god, all that imagination suddenly dries up and they can't think of a thing.

There are also rhetorical games played with infinities.  If there are an infinite number of universes, then anything that can happen will happen, and if something can (and does) happen, it will happen an infinite number of times.  This means that if Boltzmann brains are possible and they can fluctuate into existence, then they will do so an infinite number of times (but not necessarily everywhere, all the time).  Similarly, if intelligence as a consequence of cosmic and biological evolution is possible, then it will happen and it will happen an infinite number of times.  The argument is that Boltzmann brains would occur in high entropy universes (which may be thought of as being common and plentiful, and thus unsurprising) while the evolutions (cosmic and biological) that led to us could only happen in low entropy universes (which may be thought of as being rare and unlikely, and thus surprising).  We then arrive back at a sort of geocentricity-like situation, while our planet is not the centre of the universe, our universe is of a very special type rather than being typical.  From this it is argued that Boltzmann brains (as temporary denizens of the far more common high entropy universes) are more typical than we are, so we should be surprised at not being a Boltzmann brain in a different type of universe.

I disagree.

We have at least one more thing to consider, our persistence.  If we considered only one aspect of ourselves in isolation, that we are conscious and aware, then sure we might be surprised that we are not a Boltzmann brain.  But we are also persistent, we don't dissipate.  And Boltzmann brains will dissipate because, by nature, they are fluctuations in high entropy, thermally flat universes.  They represent a region of low entropy and very argument that leads to them assumes the second law of thermodynamics, that entropy increases.  The Boltzmann brain would necessarily decay, about as quickly as it came into existence, and return to equilibrium.  Absent magic, the Boltzmann brain could not choose to persist, or to replicate itself.

In other words, we are not just a thing (intelligence), we are thing of a particular type (persistent intelligence, noting that a host of other adjectives could be involved).  If I were to say that I am human, and consider only that, then I should be surprised if I was neither Asian nor African (who together make up more than three quarters of the world's population).  But if I were to note that I also have a genetic abnormality (say mutation to the melanocortin-1 receptor on chromosome 16), then I should not be at all surprised if I had pasty white skin, bright red hair, a vile temper and lived in Auchtermuchty (in Fife, Scotland not that far from Ladybank, which sounds like a euphemism - also not that far from St Andrews, ancestral home of "sweary rambling with sticks" (also known as golf)).

Being a persistent intelligence, it should come as no surprise that I am not a Boltzmann brain and for that reason, I think this rather stupid objection to multiverses fails.  (It also fails because, if Boltzmann brains are a problem, they are also a problem for monoverses.)

So, are there any meaningful objections to the multiverse other than Boltzmann brains?  Well, there are three objections from Robin Collins WLC, as summarised here by John Piippo:

For in order to be scientifically credible, some plausible mechanism must be suggested for generating the many worlds. But if the many worlds hypothesis is to be successful in attributing fine-tuning to chance alone, then the mechanism that generates the many worlds had better not be fine-tuned itself. For if it is, then the problem arises all over again: How do you explain the fine-tuning of the multiverse?

(The BGV theorem) requires that even a multiverse of bubble universes must have a beginning. In that case the mechanism that generates the bubble universes has been chugging away for only a finite amount of time. So by now, there may well be only a finite number of bubbles in the world ensemble, which may not be enough to guarantee the appearance of a finely tuned universe by chance alone. There's no evidence that the sort of world ensemble required by the many worlds hypothesis actually exists.

If our world is just a random member of a world ensemble, then it's vastly more probable that we should be observing a much smaller region of order. It turns out that a parallel problem faces the many worlds hypothesis as an explanation of fine-tuning. [Oxford physicist] Roger Penrose has pressed this objection forcefully.

The first objection, re fine-tuning of the multiverse, is merely a caution that a theoretical multiverse, presented as an objection to god as designer, cannot be fine-tuned.  Okay, thanks for that.  It's not really an objection to the multiverse per se and there's no indication that I am aware of that any of the theoretical multiverse necessitate fine-tuning.

The key element in the second objection is that there is no evidence for a multiverse, but thing is that there is evidence, certainly evidence for a multiverse generating process (watch George Efstathiou's comments, indicating that Planck data constitutes evidence in support of eternal inflation).  Even if there were no scientific evidence at all in support of a multiverse, this would not mean that the multiverse would be less supported than the god did it theory.  And with the multiverse theory, there are things that theoreticians can look out for because the theory is testable.

The third argument is actually associated with the Boltzmann brain argument (order and entropy are inextricably linked concepts).  Again, the argument is based on selected aspects of our existence and when we consider the totality of our existence, then we should not be surprised that we live in the sort of universe that we live in since it's clearly a possible universe and it's just the sort of universe that permits intelligence like ours to develop.  This objection seems to miss the point rather spectacularly.

A quite amusing aspect to Collins'  WLC's third objection is the reference to Roger Penrose (note that I changed the link to something more relevant than the Amazon page for The Road to Reality: A Complete Guide to the Laws of the Universe).  In the book that Piippo links to, Penrose mentions the word multiverse on only one page.  According to the index this was on page 783, but I could not find it on that page.  This review indicates that it might be on page 784 (which is not part of the Google Books review).  And the mention of multiverse is only to say that Penrose prefers the word "omnium" to "multiverse", a strange position to take if you are arguing forcefully against the fundamental concept (confirmed).  Additionally, Penrose's conformal cyclical cosmology is a temporal form of a multiverse, with our universe being reset and recycled ad infinitum (and Penrose claimed that circular patterns in the CMB data from WMAP were suggestive of earlier universe, some might claim that they are suggestive of young bubble universes bumping into each other or side-effects of inflation, while others might suggest that some people are just seeing what they want to see).

<edit> The blogger measureoffaith (see comments below) suggests that Penrose forcefully makes the case that multiverses face the same problem with fine-tuning that our universe does in sub-chapter 28.7 The Big Bang’s special nature: an anthropic key?  It would appear, however, that this section must be read very optimistically by a theist, especially when Penrose's conclusion mirrors mine - that it comes down to either design or chance, that god did it or there's some mathematical/scientific reason why the universe is the way it is, and that it's worthwhile investigating the latter.

Robin Collins also presents some objections to the multiverse, in this document.  His objections relate to the nature of a "many-universes generator".  I wrote about these objections in "The Four Mechanisms of the Ignopalypse", but I am holding off on publishing it (or was at time of writing, if you are reading this later).  It should be up later in the year.  For the moment, suffice it to say that I don't find Collins' objections to be meaningful or substantive. <end edit>

If there are any meaningful and substantive objections to multiverse theory, I would be keen to hear of them but so far there seems to be little more than a chorus of appeals to incredulity.

In conclusion, the fine-tuning of the universe can really only be explained by chance or design, since all other objections resolve down to one or the other.  I'm not overly fussed by the nature of the designer, since I don't consider a designer to be the correct answer anyway (for other reasons, quite separate from the theoretical impossibility of design).  That said, given the nature of the design argument, nothing we ever come across will be sufficient to eliminate design as a theoretical possibility - since a designer could have created the universe with the intention to make it totally indistinguishable from a universe that came into existence by chance.  All that we have is a counter to the argument that a designer must exist because there is no other alternative.  We do have an alternative, in the form of a multiverse.

Something that is worth considering, particularly if you are a pro-fine-tuning, anti-multiverse theist, is that science is inching closer and closer to proving that the multiverse is reality, rather than just hypothesis.  If you have nailed your colours to the notion that fine-tuning is a knock-down argument for god because you think that the multiverse might not exist, it is high time that you reconsider your position. (Much as Jeff Zweerink has - listen to the second impressive moment.)


  1. FYI, the objections you list here appear to have been sourced from WLC rather than Robin Collins, and the accompanying reference to Penrose is on pages 762-765 of TRtR.

    1. Thanks, I've updated accordingly. I don't think that pages 762-765 say what you want them to say. Penrose is arguing against the anthropic principle. Towards the end of an earlier section, "28.6 The anthropic principle", he writes (having linked the strong anthropic principle with a creationist god hypothesis):

      "My own position is to be extremely cautious about the use of the anthropic principle, most particularly the strong one. My impression is that the strong anthropic principle is often used as a kind of ‘cop-out’, when genuine theoretical considerations have seemed to reach their limit. I have not infrequently heard theorists resort to saying something like: ‘the values of the unknown constant parameters in my theory will be ultimately determined by the anthropic principle’. Of course it might indeed ultimately turn out that there is simply no mathematical way of fixing certain parameters in the ‘true theory’, and that the choice of these parameters is indeed such that the universe in which we find ourselves must be so as to allow sentient life. But I have to confess that I do not much like that idea!"

      Note that he moves from having particular issue with the strong anthropic principle to just referring to it as the anthropic principle. Thus, when he's protesting strongly against the anthropic principle in a later section, he is most particularly protesting against the strong anthropic principle, and thus against your god. Given the context, it's a little disengenuous to call upon Penrose in support of your case.

      I see no strong objection in Penrose's book against multiverses. Even when we limit ourselves to the very specific thing that WLC could be thought of as honestly referring to - the extravagance associated with having such a large, long-lived universe when perhaps we need a much smally region of order, no more than one galaxy, with the current laws in place only for as long as required for humans to evolve - we see that Penrose is arguing that for the purpose indicated (creating us, apparently) there would have been 10^10^123 more options that were significantly less extravagant. This is a strong argument against god, not a strong argument against multiverses. If anything, it implies that if there are multiverses (and thus more likelihood of the initial conditions from which intelligent life might spring) then the argument against god only increases.

    2. And in case it wasn't obvious, 'Travis R' = 'measureoffaith'.

  2. You assume too much. I don't "want" Penrose's argument to say anything in particular, nor am I making a case for any particular view. I was simply skeptical of the story put forth in your original version and so wanted to inform you of the correct sources after locating them for myself. Perhaps I should have been more explicit - it is WLC, not me, who refers to pages 762-765 of Penrose's TRtR in the context of the quote. So the point was that your remarks about WLC presumably (and amusingly) referring to pg 784 is a strawman and is probably best exorcised from the post. As far as I can tell, WLC accurately characterizes the cited argument from Penrose, though he simultaneously fails to acknowledge the accompanying implications for theism that you outlined.


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