How to Fine-Tune Arguments for God’s Existence

Every year we see new books being published on the intersection of science and faith. In 2016, particle physicist Peter Bussey (PhD, Cambridge) added his take on the conversation to that list. Besides his research fellowship at the University of Glasgow, Bussey is also a committed Christian and a writer for Science and Christian Belief. Bussey has no qualms with most conclusions of mainstream science (e.g., the age of the universe and common descent). In principle that means he is an Evolutionary Creationist. The title of his new book is Signposts to God: How Modern Physics & Astronomy Point the Way to Belief. Bussey aims to show that these domains of science have not only been faith-friendly throughout history, but actually contain useful pointers to the belief in a Creator who purposefully made our universe and us in it.

Fine-tuning the fine-tuning argument

One of the main points Bussey develops in his book is based on the following observation:

At the very least, our own planet must be of a suitable kind, located in a suitable region of the universe, such that human life is possible on it. This is obviously true, and there are many planets for which it is not true, drawing our attention to the fact that not all planets can generate advanced life. Much more significant is the fact that for us to be here, the universe itself must have suitable properties. (…) This statement is normally called the “weak anthropic principle.” (p.94)

The emergence and continued existence of complex life in our universe is fragile. I believe this can trigger a genuine sense of wonder about Creation that can ultimately point to God. However, it appears to me that Bussey’s way of presenting the argument is not “fine-tuned” enough to actually do the job.

For starters, we need to focus on the big picture. Together, the laws of nature form an integrated whole that sustains the complexity of conscious life. It’s easy to get lost in the details by compiling a long list of properties of the universe that are precisely suitable for complex life on earth. Bussey writes: “With the complex history of the universe kept in mind, we are in a position to write a basic ‘shopping list’ of conditions that would allow a planet with advanced life to form” (p.96). He goes on to list about ten physical constants that are “right” within ranges that appear to be quite narrow.¹ I am sceptical of reliance on the narrow range of these physical constants. A hypothetical alien race in a hypothetical parallel universe might be wondering about completely different constants that were essential to its development. It is more relevant to emphasize the entire structure and pattern of our universe that sustains the complexity we observe. That beauty is essentially what triggers the “wow factor.”

There is enough scientific material to fuel the “wow factor” without relying on questionable or controversial claims. For example, Bussey makes the mistake of resorting to probability and randomness to argue how unlikely our universe is: “For these reasons, I have not attempted to provide a precise value for the ‘probability’ of a human-friendly universe, although by any considerations it would appear to be extremely small for this to happen by chance” (p.112). This claim is debatable because we experience only one universe. There is no way to say something definitive about the initial set of possibilities or the “probability” of our current universe. Bussey also invokes entropy of the universe as a “special” setting. Entropy is a measure of the amount of disorder in a system. It currently looks like our baby universe was extremely smooth, which can be interpreted as low entropy in the context of gravity.² Bussey claims that, “if our present universe derived from a previous one, then it should almost certainly have more entropy than it has” (p.102). This claim is debatable because (i) we have a limited understanding of the very early universe and (ii) the entropy of the whole universe is difficult to pin down.

Fine-tuning, in its most elegant form, is a positive argument about the intricate structure of the universe as a whole. When we rely on unexplained questions regarding the physical constants of our universe, we risk turning it into a negative story. Bussey tends towards that direction. For example, he correctly notes that the value of the cosmological constant contradicts theoretical expectations. The cosmological constant is a term in Einstein’s equations that allows for “dark energy”, a mysterious vacuum energy that fills the universe.³ However, the amount of dark energy is much, much smaller than we would expect for a vacuum energy based on quantum physics. It’s actually off with a factor of 10¹²⁰.This has been labeled “the worst prediction in the history of physics!” Based on this, Bussey proposes that the cosmological constant “may well be small for a non-theoretical, anthropic reason, for if it were much larger than it is, we would not be present to observe it” (p.101). I believe it is unwise to turn fine-tuning into an argument based on the gaps in our understanding, because the properties of the universe could become more amenable to scientific explanation in the future.

Watchful readers will have noticed that the pitfalls discussed here have almost one-on-one equivalents in common arguments of the Intelligent Design (ID) movement. ID proponents have used arguments from probability, entropy, and gaps in our current understanding of nature to make inferences about the existence of a “designer.” Indeed, this entire discussion could be transposed to one of biological science. To be fair, Bussey does state in his book that he disagrees with the ID movement as far as biology is concerned. However, that does not take away from the fact that he employs almost identical lines of reasoning in his fine-tuning argument.

Responses to the “Wow Factor”

In his book, Bussey lists four main responses to the fine-tuning argument:

1. No explanation is needed.
2. A Creator purposefully arranged it.
3. Our universe is only one among many in a multiverse.
4. There is an undiscovered cosmological theory that explains these properties.

This is not meant to be an exhaustive list (see footnote⁴ for a few other options). Although Bussey does mention that these four options are not mutually exclusive, listing them in this way inadvertently gives them a status of equivalence in the mind of the reader. I believe that is unhelpful. Instead, I will discuss them in terms of the “wow factor” and the different kinds of explanation they provide.

Of course, it is in principle possible for someone to remain unimpressed even while contemplating the intricate structure of the universe as a whole and us in it. This would be a valid reason to appeal to option 1. However, I have yet to meet a person who can actually make such an assertion with a straight face.⁵ Let us suppose it does trigger that deep sense of amazement about our existence in this universe. Then how do we make sense of that? A theist of any kind could immediately respond that it is all due to the Creator who purposefully arranged it (option 2). This is a valid ultimate explanation, but it should not be seen as a placeholder for natural mechanisms, such as options 3 and 4. Instead, it can encourage us to dig deeper and try to uncover underlying natural causes for those properties of our universe. Such discoveries can further amplify that sense of amazement, strengthening the need for an ultimate explanation (option 2). It’s worthwhile to discuss them to see how that plays out.

It is entirely possible that our universe is only one among many in the multiverse. A theoretical picture that is currently popular among cosmologists is that of a sea of chaotic quantum fluctuations, one of which led to inflation and established our universe. If one of those fluctuations could have established our universe, others could probably have triggered yet other universes with completely different laws of nature. This would make Creation look even more amazing than in the case of a single universe. It could also be that the apparently fine-tuned physical constants will eventually follow directly from an improved cosmological theory. If all those apparently independent elements would end up following from a single unified framework, it would gives us all the more reason to exclaim, “wow!” Underlying natural explanations for the properties of our universe will therefore cause us to marvel even more at the intricacy of it all. That inevitably brings us back to the need for an ultimate explanation. The same idea pops up in the context of the First Cause argument for God’s existence, which we will now discuss.

Fine-tuning the First Cause argument

The First Cause argument posits that everything natural requires a cause, which would imply some sort of ultimate “uncaused” Cause. Again, this line of reasoning can be useful if considered carefully, but its wielder needs to navigate around several rhetorical pitfalls. For example, Bussey argues that there must have been a First Cause at a definite point in time. Frankly, I do not believe such an approach is fruitful, for several reasons.

Any argument that focuses on time in the early universe won’t hold much water for a cosmologist. Time itself becomes increasingly difficult to define when we come closer to the singularity of the Big Bang. We just don’t know enough about that singularity to make very definite statements about what happened “before” it. Instead, it can be more constructive to focus on what is continuously upholding the existence of time and space itself. That allows us to speak of the First Cause in the sense of the “primary” or most fundamental cause of the universe. Bussey does allude to this possibility but considers the First Cause in time a stronger argument. I disagree with that approach because it overplays our poor understanding of the very early universe.

Proving that everything came to exist at a definite point in time seems to be an unnecessary exercise, from a Christian perspective. The Big Bang model already shows that the world as we know it had a definite beginning and that it arose from primordial formlessness. This is true whatever may or may not have happened “before” the singularity. As a Christian, I can leave it at that and avoid making definite statements about something we don’t understand completely. An interesting parallel can be found with the biblical narrative here. Some interpreters see a conception of a pre-existing chaos in Genesis 1:2: “Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.” Even though the text is strikingly ambiguous about the origin of this chaos, the clear focus of Genesis 1 is that all of Creation reflects the wisdom, power, and care of God.

Another, related pitfall is to try to defeat all appeals to an eternal physical system. For example, Bussey asserts that “a proposed infinite physical system needs a rigorously well-defined description before it can be taken seriously.” This demand is pedantic given our limited knowledge of the universe and our conceptual limitations in thinking about infinities. It’s like saying that an infinite God needs to be well-defined before any proposal of God’s existence can be taken seriously. We need to be fair to those with whom we disagree.⁶ Interestingly, Bussey also draws from coordinate transformations to argue that even an infinite history can be compressed into a definite set of events:

If the history is transformed so as to be finite, this entire set of events becomes squashed into a singularity at the new beginning of time, which might be problematic. However, it may be valid to treat this entire structure “as a whole.” (p.137)

Transforming coordinates in this context simply means that you define the time on your clocks differently.⁷ It may seem convenient because it can produce almost any conclusion you prefer. But if we look at it closely, such an argument becomes self-defeating. One could turn Bussey’s reasoning around to argue that any finite set of events can be stretched out to extend across an infinite amount of time if we tweak our clocks enough.⁸ Of course, if somebody would make such an argument it would sound rather ridiculous. Coordinate transformations are so flexible that any eternal universe can be made to look finite and vice versa. This line of thinking actually reveals the futility of trying to pinpoint the First Cause in time.

Christians do not need to be frightened of the possibility of an eternal universe, because it still invites the question what causes that eternal system to exist at all. As a Christian, I believe in a personal God who simply declares “I AM” (denoted by YHWH) and that this God created nature. In that sense, God is the First (or most fundamental) Cause of nature, including time and space. An atheist, however, needs to assign this power of declaring one’s own existence to nature by admitting that “IT IS”.⁵ That is where the real problem lies. Granting nature such god-like powers makes it into another god, albeit an impersonal one. If atheists accept nature as their god, they aren’t atheists after all. That would lead to the idea of a pantheistic God who is nature himself. The same kind of belief was held by figures such as Spinoza and Albert Einstein. This makes clear that arguments for God’s existence from nature cannot bring us to know God. For that, we need Jesus Christ and the message of the Cross as revealed to us in the Scriptures.