God and the Friendly Universe

The proposition that the universe is hospitable to human life, potentially supporting a teleological argument for God, is implausible at a first glance. So far as we now know with certainty, the universe is congenial to human life only on the rind of one minor planet of one among 10²¹ stars. Almost all of the real estate of the universe is distinctly hostile to biological organisms, and this will remain the case as a matter of the percentages even if the recent success in finding extrasolar planets turns up some that are good candidates for life.

A second glance, however, reveals some developments in theoretical cosmology that may seem to give currency to the old saw that God made the world for our use and enjoyment. Theists (and a few of the very few deists there are) draw our attention to the “fine tuning” of certain physical constants and initial conditions, a fine-tuning that makes the existence of life possible.

The “fine-tuning” label is, of course, already loaded. In our experience only people tune things at all, roughly or finely. A more neutral way of putting it is that the values of some physical constants and some initial conditions of the universe must fall very close to their actual values or we could never have developed – because, among other inconveniences, atoms would have been wildly unstable or the big bang would quickly have collapsed into a big crunch or the matter of the universe would have run away from itself too fast for stars to form. The constants in question include, among others, the strong force, weak force, gravitational constant, Planck’s constant, charge on the electron, speed of light, cosmological constant, density of matter, and the number of “large” dimensions. If any of these had been very different, we, apparently, would not be. 

 

There are currently three major camps and one minor camp with respect to the fine tuning of physical constants. Camp 1: The fine tuning is exquisitely improbable, an improbability that can only be explained by God. Camp 2: The fine tuning is exquisitely improbable, an improbability that is, however, nicely explained if ours is only one of many actually existing universes. Camp 3: The fine tuning may be exquisitely improbable, but, if so, it is the sort of improbability that requires no explanation. Because we are here it is inevitable that the constants and conditions would be right for us. Camp 4: Probabilities cannot properly be applied to the values of the fundamental constants and initial conditions.

The Camp 1, made up of deists and theists, has a straightforward position. Physical theory shows that the basic constants and certain big bang initial conditions must fall within a very small, “Goldilocks zone,” for life to be a possibility in the universe. That this should be the case is wildly improbable unless an intelligence that is looking out for life was responsible for the initial cosmic recipe.

Camp 2 goes along with Camp 1’s intermediate conclusion that, if this is the only universe, then it would be wildly improbable that the constants and initial conditions would fall within the Goldilocks zone. The attractiveness of positing a creator who was looking out for our interests disappears, however, if our universe is only one of very many. Our sister universes will have all of the “bad” values for the physical constants. It will be their misfortune that atoms never form or that infant star systems collapse in an early crunch. Making a modest borrowing from Camp 3, the members of Camp 2 argue that it is inevitable that we will be in one of the good (for our existence) universes.

Camp 2 has astrophysics going for it – at least as of now. (These things can change quickly.) There are good astrophysical reasons, quite apart from the fine tuning question, to think that reality may well be a multiverse. The currently most widely accepted “inflationary” model of the Big Bang, is multiverse-friendly.

Camp 3, with Dawkins as honorary Camp Director, insists that no positive probability, however low, for the constants and initial conditions essential to human life is the least bit surprising or in any need of explanation. No explanation at all is required for extraordinarily improbable values of the physical constants. That a particular sperm cell should fertilize a particular egg, leading to you, was an astronomically unlikely event. You might reasonably feel grateful, but you do not ask yourself, “How could this possibly have happened without some extraordinary intervention?” Some great improbabilities cry out for explanation; others are just the way things fell out. It is a wonderful philosophical question just how we are to draw the line between the two.

Dawkins claims a partial solution to the what-needs-an explanation problem in the famous “anthropic principle.” It is this principle that serves as the founding charter of Camp 3. Observational results that could not have been different if the observation was going to be made at all never require special explanation. The principle in its general form is related to observational bias in sampling. If I want to know what percentage of animals are air breathers, I had better not conduct the entire survey above the surface of the water. If astrophysicists look out to see whether the universe has physical conditions conducive to the development of astrophysicists, the answer is inevitably going to be “yes.”

It really is uncontroversially inevitable that, when astrophysicists look out at the universe, they are bound to find it in a shape consistent with their looking out at the universe. For that matter they are bound to find it in a shape consistent with Custer’s defeat at the Battle of Little Bighorn. Everything, including all of the underlying physical properties of the universe must, of course, be consistent with everything that is. To return to the problem from a different direction, how far should this after-the-fact inevitability count as a satisfactory explanation?

When it comes to the conditions necessary for human life, Dawkins thinks that the anthropic principle gives us all the explanation we should seek.

the beauty of the anthropic principle is that it tells us, against all intuition, that a chemical model need only predict that life will arise on one planet in a billion billion to give us a good and entirely satisfying explanation for the presence of life here (God Delusion 138).

This cannot be right in the way Dawkins puts it for the following reason. If there is a second chemical model that predicts that life will arise on one planet in a mere billion, that might well be a much better explanation for life here, in which case the first model could hardly be “good and entirely satisfying.” In fact, we would want to know more about both models before deciding just how satisfied we should be with either.

What Dawkins might better have said is that it does not doom a chemical model if it predicts life on one in a billion billion. An extreme improbability could be part of our story without the necessity of any further explanation of its extremity. But the move from “might not require” to “does not require” explanation makes for an aggressive use of the anthropic principle. This aggressiveness is required to reach the conclusion that no explanation should be sought even if the joint probabilities of everything’s falling within the Goldilocks zone are infinitesimally small.

Let me add one observation that does not justify Camp 3’s aggressive anthropic principle, but should give that camp some comfort. The need for an explanation of something does not follow from the possibility of its having an explanation. Consider a nondescript pile of sand. It would have an enormously complex grain by grain description and and intimidatingly low antecedent probability of coming into existence. It is possible that some super-engineer started from the complete description and painstakingly assembled a pile of sand to correspond. This would provide an explanation for why the pile of sand is as it is. The possibility of such an explanation, however, does not increase our desire or need for that or any similar sort of explanation. God could well be the explanation for why the constants are what they are, but that possibility does not itself mean that there is a need for any explanation.

This consideration does not, by itself, make a positive case for putting the Goldilocks constants on the “no explanation needed” side of the line. There are some worthy objections to doing so, but also some serviceable responses to those objections. Pursuing this any deeper would bring us into serious technical issues. So I am going to leave the matter here for now without declaring either victory or defeat for Camp 3. I am the more reconciled to this retreat because there is a great deal to be said for Camp 4, which could put Goldilocks to rest without any help from Camp 3’s strong anthropic principle.

Before heading on to Camp 4, it is worth acknowledging that a merger could be negotiated between Camps 2 and 3. MIT astrophysicist and professor of creative writing Alan Lightman: “We are an accident. From the cosmic lottery that containing zillions of universes, we happened to draw a universe that allowed life. But then again, if we had not drawn such a ticket, we would not be here to ponder the odds.” (The Accidental Universe: The World You Thought You Knew, 2013.) Of course, the more radical members of Camp 3 would consider Lightman to be leading something of a hostile takeover. Dawkins, for example, would insist that, with the anthropic principle in motion, the multiverse is a fifth wheel on the Goldilocks bus.

It is the Camp 4 position that is minor in the sense that it is least talked about. It is also, so far as I can tell, correct. The idea is that, although it might intuitively seem improbable that, e.g., the charge on an electron should fall within one percent of its actual value, there is no good way to give substance to that intuition. 

We have a basis in past experience and physical analysis to apply a probability to a deuce on the next role of a given die. We have a basis for estimating the probabilities that a particular trial witness is lying. Nothing in our experience and nothing in our science, however, gives us a basis for assigning probabilities to the charge of an electron’s being within a certain range. 

(Because all electrons have measured at a single value, to within experimental error, we have that basis for assigning a probability of one to the charge’s falling within one percent of its actual value. Camp 4 probability skepticism does not apply to that probability, but, of course, that probability is exactly the opposite of what the fine tuning argument needs, which is a very low probability not a very high one.) 

There are, in addition, mathematical reasons for skepticism about the application of probabilities to the values of the fundamental constants (Timothy and Lydia McGrew and Eric Vestrup, “Probabilities and the Fine-Tuning Argument: a Sceptical View,” Mind 110 (2001): 1027-1037.)

Thus Camp 4 argues that no probabilities, not even rough ones, can be applied to the physical constants’ having values close to their actual ones. With that, the fine tuning argument fails, at least in its usual form. There is no infinitesimal probability to be explained, and we do not even reach the Camp 3 issue whether it is the sort of improbability that cries out for explanation. So, if Camp 4 is right, then we do not need to postulate either a Fine Tuner or a multiverse, although we might have other grounds for believing in the existence of either or both.

To sum up, the fine tuning argument faces three hurdles. Camp 4 has underappreciated, but weighty, arguments that there is no improbability in the apparent friendliness of the universe. Camp 3 gives good, if arguable, reasons to think no explanation would be needed even if there were an improbability. Camp 2 gives an attractive alternative explanation, supported by current astrophysical theory, for the improbability if there is one and if it needs to be explained.

For these reasons, I do not now see here an argument for the existence of God. However, there is just too much difficulty and too much intellectual ferment to conclude that the Goldilocks array of physical constants and initial conditions are unworthy of consideration on the God question. For my own part, I take some small comfort in the hope for the existence of a God who set things just so. Wherever there is need for caution about the arguments that derail an argument for God, it is some sort of plus for a theistic hope.

This post was excerpted from my book. Hope to God. https://scribl.com/books/E9HZ8/hope-to-god. Also available as an Amazon e-book. 

For more on hoping for the existence of a God for whom there may be too little evidence for belief see my post of 5/5/15.