Astronomy, cosmology and especially the origin and “fine-tuning” of the universe have long been of interest to me. So I was interested to hear a recent radio discussion between cosmologists Sean Carroll and Luke Barnes, where they discussed the start of the universe, fine-tuning and God.
For those who may be unfamiliar, cosmologists have found that the character of our universe is governed by about a dozen important numbers that define physical laws such as the size and charge on elementary particles, the strength of fundamental physical forces, and the overall density of the universe. And of all the possible values it appears these numbers could take on, only an extremely small range would allow a complex, long-lived universe that could support intelligent life.
This much is pretty much agreed on by cosmologists, but there is much dispute over whether there is a scientific explanation for all this, or whether it is evidence of design, and, by implication, for God.
Sean Carroll is an atheist who has taken an interest in the philosophical issues that arise from scientific fine-tuning, and has developed his philosophical thinking more than most – for example, he has debated with christian philosopher William Lane Craig. But Carroll seems to be a little “left field” among cosmologists, questioning the reality of scientific fine-tuning more than most, and holding to some scientific viewpoints that are unusual (e.g. he is more sceptical than most about cosmic inflation than most). He has written The Big Picture on the “origins of life, meaning, and the universe itself”.
Luke is a cosmologist beginning to make his name. He has written a paper on fine-tuning, and co-authored A Fortunate Universe: Life in a Finely Tuned Cosmos with his colleague Geraint Lewis (who is an atheist). I have followed Luke’s blog for some time. I knew, as he confirms here, that he was raised as a christian, but all his discussion of fine-tuning has been very neutral about God – either he was agnostic or very guarded about his beliefs. But in this radio interview, he identifies as a christian theist.
Worth listening to
I don’t listen to many podcasts or watch many videos, they can take up so much time. But this hour and a half was well spent, though I would have liked the presenter to be a little more succinct. Several things struck me.
It was so good to hear an atheist and a christian treat each other with respect and apparent friendship. I presume this comes easier for them because their cosmology gives them so much in common, and so much in each other to respect. But they both seem like genuinely warm and pleasant people, and seemed to respect the religious and philosophical views of each other even while they disagreed. If only others ….
One of Sean’s main arguments against any theistic interpretation of the universe was to simply say that whatever explanation we adopt, something will have to be simply a brute (i.e. unexplainable) fact, so why not simply say that the universe is that brute fact. Why does it need an explanation.
Luke’s response was to say that humans like to answer questions, and if we finally knew everything there was to know about Physics, we wrote the equations up on a blackboards, and said science had solved everything, we can (and probably should) still ask why is that blackboard full of equations so? And if there is an explanation, it must be something beyond science.
I am obviously biased, but I thought Luke’s point was telling. If we want to solve all of Physics, why wouldn’t we want to go beyond that and solve other questions too?
A beginning to the universe?
Both cosmologists accept that science has not yet established whether there was a beginning to the universe or not. Luke says that if there was a beginning, he would feel more comfortable with theism as an explanation than with naturalism, which has no explanation and has to accept this momentous event as another “brute fact”.
However Sean said he was quite comfortable with the brute fact of the universe starting, and he says theism has its own brute facts, for example, the existence of God. He says “cause” is not a scientific concept and he is also critical of statements that infer there was nothingness and then after some time a universe “popped into existence”. Both he and Luke agreed this terminology is unfortunate, but Luke still feels that if a universe began, it is sensible and important to ask why?
Making a prediction
Science is based on forming a hypothesis and then testing against the data. For Sean, if naturalism is true, we’d expect the sort of random, sometimes chaotic universe we see. But if theism was true and humans are important to God, he’d expect the universe to be smaller (why make it so large?) and not as finely tuned (why would God need to set up the laws so that there are so many other theoretical possibilities?). Besides, he says, the universe seems to be working in a predictable manner with no signs of God interfering. So he sees the size and fine-tuning of the universe as pointing to a physical mechanism as the best explanation.
Luke’s response was to say that if naturalism is true, we can say nothing more than that we can’t know about the explanation, the universe is this way randomly. But the scientific facts of fine-tuning are totally unexpected on naturalism, but quite explicable on theism. And he thought the universe might be predictable because God wants it that way so humans have a stable external environment, and its size leads people to think of God, which presumably God would be pleased with. So at least, he thinks, theism provides some extra useful information and explanation that naturalism doesn’t.
Is the science of fine-tuning clear?
Luke has assembled in his paper and book a lot of evidence for fine-tuning, and has the support of many, probably most, of the big names in cosmology. But Sean expressed a number of doubts about the science. He isn’t sure the parameters are really finely tuned, and he thinks recent work has shown that some apparent fine-tuning has a natural explanation. He suggested we can’t know for sure what effect varying the various parameters would have, but Luke was firm that theoretical physics can tell us that.
Sean believes the multiverse (the idea that there are zillions of universes, each with different properties, and of course life only arose in the rare universe that allows it) is a more likely explanation than something non-scientific, but Luke pointed out that the multiverse still doesn’t answer the question of how is it that the multiverse creates zillions of universes all with different laws and parameters? Sean countered by saying the science predicts that different regions of space will have different laws.
God as an explanation?
Sean thinks God doesn’t provide any sort of explanation. He points out that God is not an explanation that anyone doing cosmology uses in their scientific work. He also argues that if fine-tuning establishes anything, it isn’t that it is fine-tuned for life, but for complex chemical reactions, and theists generally believe that life is more than that. I didn’t see the point in this argument, and Luke simply said the complex chemistry is necessary for life. Luke said that he felt none of Sean’s objections amounted to much compared to the problems that fine-tuning raises for naturalism.
So where does this leave us?
It is difficult for a layperson to make judgments here, because expert cosmologists know so much more than we do. As a layperson, I am looking for scientific facts that the experts have explained so I can understand, and then practical explanations and conclusions based on those facts.
On that basis, I still feel the origin of the universe and fine-tuning are difficult for naturalism to explain. I find Sean’s common response of saying he doesn’t think we can demand an explanation, that he is OK with brute facts, and we need to be humble and not claim too much, somehow lacking or unconvincing. In science, it is wrong to draw a conclusion until one has sufficient data and demonstrable evidence, but in life, in philosophy, and even in applying science into the practical world (as I used to do as an environmental manager) we are often required to do just that within a given timeframe.
But of course Sean may be right that the common ideas of cause and beginnings are not applicable, and it is only my lack of understanding of complex physics that leads me to think so crudely as to think as I do about cause and beginning, and to conclude that the universe points to God.
But there is little I can do about this. I feel it is crucially important to answer the “God” question if I can. So if Luke contests some of Sean’s science, and sees no barrier to believing God is a better explanation of cause and tuning than naturalism is, I have to conclude that the science and my limited understanding are not barriers, and I can only go with what seems to me to be most consistent.
Clarifying both the science and the philosophy is one of the benefits of a discussion like this, and if you are interested in cosmology, you may find it similarly helful.
Photos from Premier Christian Radio