Big Bang, fine-tuning and the limits of science – can cosmology point us to a Creator?

‘For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountain of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries.’

– Robert Jastrow, God and the Astronomers

The ‘story’ to which astronomer Robert Jastrow referred was the story of twentieth-century cosmology. In the conclusion of his classic 1978 study, recent developments in Jastrow’s field had pointed inescapably to a datum that theologians of the Abrahamic faiths had held all along: the Universe had a beginning. It was not fixed or eternal.

More recently, a study by entrepreneur Michel-Yves Bollore has arrived at the same conclusion, furnished by a new set of cosmological proofs. Not only did the Universe begin to exist – a point which might seem to require a transcendent creator – but it appears uniquely designed to support life. If the constants of nature were out by a hair’s breadth, there would be no stars, no carbon, no humans. 

Michel’s best-selling book, God: The Science, the Evidence, was written alongside mathematician Oliver Bonnaisses with the help of twenty high-level scientists. Yet not all scientists are convinced. A case in point is Dr Niayesh Afshordi, co-author of the highly acclaimed Battle of the Big Bang. According to Niayesh, a cosmologist at the University of Waterloo, the jury is still out on whether the Universe had a beginning, while fine-tuning is not clear evidence of a fine-tuner. In this week’s Unbelievable? I got down to brass tacks with Michel and Niayesh in a debate on whether cosmology has really ‘proved’ God.

Read more:

Does science prove God?

How we all came to think science and religion were at war

Atheism and the ignorance of science

How churches can embrace science?

Did the Universe Begin to Exist?

The first touchstone in the debate was the perennial question: did the Universe have a beginning? Michel brought the evidence of the Big Bang and the second law of thermodynamics. The ‘big bang’ may suggest that the Universe emerged from a singularity – when time began –  while the second law of thermodynamics implies that the Universe’s energy will one day run out. If the Universe were eternal, it would have had an infinite amount of time to run out. But it hasn’t. Thus, the Universe is not eternal.

Yet Niayesh contested this understanding of the Big Bang. For Niayesh, we must be careful to distinguish between two definitions of this term. In layman’s terms, the ‘big bang’ is commonly understood as the beginning of time – the singularity. Yet many scientists hold to a ‘weaker’ definition of the Big Bang as the early inflation of the Universe from a hot dense state. This latter definition is well supported by a range of evidence, such as the discovery of cosmic background radiation. But for Niayesh, it does not say anything about the beginning of the Universe. It does not tell us what happened before the early expansion. What happened before the Big Bang? Scientists have put forward various models, but none of these have garnered consensus – there are still many unknowns.

I left this question with two distinct impressions. First, that cosmological proofs for an absolute beginning might not be as strong as philosophical ones. And second, that the science of the early Universe is still in its infancy. With so many models of the early Universe – some eternal, some not – supported to various degrees by different bits of evidence, I wonder if it is wise to place one’s faith in the ever-shifting scientific landscape. The universe might be eternal one day, and not tomorrow, and vice versa. 

Is the Universe Fine-Tuned for Life?

The second touchstone of the debate was the ‘fine-tuning’ of the Universe. Michel laid out some of the constants of nature, which have to be precise to a staggering degree for human life to develop. This fine-tuning, described by philosopher Philip Goff as another Copernican revolution in science, certainly has the capacity to make the sceptic reconsider their worldview. Philip Goff came to faith in part because of this discovery, and the late Christopher Hitchens confessed it is a point with which one has to wrestle.

But does fine-tuning point to a fine-tuner? In a point of agreement with Michel, Niayesh is not enamoured by the Multiverse theory. We do not just happen to find ourselves in a Universe in which life exists (although that is an option on the table). But he is also not convinced it is evidence for God, raising two arguments against it. First, he pointed out that in a recent survey conducted with Phil Halper, the most common way to account for fine-tuning is to consider it a brute fact. We don’t ask why a triangle’s angles add up to 180 degrees. They just do. Nothing is surprising about it.

Another issue which came up in the debate concerned probability. How do we calculate the likelihood of any particular Universe containing life? If I roll a die, I know that the chance of getting a six will be 1 in 6. I know this because I know that there are six sides of the die. But if I throw two dice, the chance of getting a 6 rather than, say, 2, is much higher, because there are more combinations which allow for a 6 than a single combination which allows for a 2. For Dice, we can clearly define a probability distribution. But can we do this for the Universe? Many scientists, including Niayesh, have concluded that we do not.

Once again, I was left with the sense that there is much we do not know – and that might be okay. The believer may awe and wonder that the constants of nature are such as to permit life, a point which is congruous with their worldview. Yet others might explain the same evidence by appealing to a multiverse, brute facts, or cosmological natural selection (think natural selection, but for Universes borne of black holes rather than species). If time permitted, however, I would have liked to press Niayesh further on the notion of a brute fact. What exactly would it require to make this theory more probable than another?

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Cosmology – A Ground for God?

A final thread in the debate was the idea of a ‘God hypothesis.’ Michel confronted us with a stark dichotomy: either we accept the God hypothesis, which predicts the evidence we see in cosmology, or we embrace materialism, with its rather bleak consequences for human life. For Niayesh, however, the problem of ‘other religions’ arises. There are many worldviews, and cosmology cannot begin to adjudicate between them.

Michel clarified that the ‘God’ he posits as a hypothesis has nothing to do with religion. It is the God known through reason and science – the God of the philosophers. Yet even if we accept this framing, it is a false dichotomy to assume that the options are between this ‘prime mover’ or ‘fine tuner’ and materialism. There is a whole panoply of religious and philosophical positions which do not posit a God separate from the Universe who created it – we might think of various strains of the Dharmic faiths. Equally, there are plenty of brands of atheism which require no commitment to materialism – Platonism and Panpsychism are just a few popular options on the non-materialist menu.

I think that it is also questionable whether God should be likened to a scientific ‘hypothesis’ with serious predictive value. As one Christian philosopher at Princeton, Hans Halvorson, points out, the hypothesis of a life-loving God would support the expectation that the Universe’s constants would allow for life. Why then do we see the odds for life as astronomically low? Equally, Phil Halper has asked what it means to say there are non-life permitting Universes. If we are working with the idea of an omnipotent deity, does it not follow that all Universes are life-permitting? In the end, I think that the idea of a God hypothesis is tricky to get one’s head around – the notion of God as a hypothesis is certainly not the view held by many religious believers today.

Cosmology and Belief Today

Thrumming beneath these debates was the question of the proper relationship between cosmology and belief. I certainly resonate with Michel’s perspective that recent discoveries may seem congruous with the notion of a cosmological creator. Yet personally, given the number of unknowns, I am driven more to awe and wonder at the mysterious character of the Universe – feelings which feel a home within my worldview – than to the airtight conclusion that science shows that a creator God exists. A Universe which emerged as a black-hole, or a cosmic bounce, or in which time travel is possible? These are surely possibilities – even if far from proven – that might make the theology of creation even more remarkable, even more glorious, than we had ever imagined.

The Psalmist writes: ‘The heavens declare the glory of God, and the sky displays the work of his hands.’ This is poetry, not argument, but I can only imagine what the Psalmist would express if he knew about the Universe what astronomers like Niayesh are coming to see. It is within this poetic frame that cosmology and faith can lie side by side as happy bedfellows. Cosmologists continue to reveal how the ‘heavens declare the glory of God.’ Yet this leads us as embodied people into awe and wonder, not decisive proof.

Dr John Nelson is a host of the Premier Unbelievable? podcast, he teaches Theology & Philosophy at Haberdashers’ Boys’ School, writes Behind the Gospels and is Producer & Researcher of the history podcast, Biblical Time Machine. His revised PhD thesis at the University of Edinburgh is forthcoming as Jesus’ Physical Appearance: Biography, Christology and Philosophy (2025).