Big Bang Cosmology: Unsettling Implications for Atheism

The Emergence of the Big Bang Theory

Before the groundbreaking discoveries of the 20th century, many scientists believed in the idea of an eternal universe—one without a beginning or end that remained constant over time. This idea was popular because it seemed to simplify some of the biggest questions about existence. If the universe had always existed, there was no need to wrestle with questions like how it began, why it exists, or whether it was created. This perspective was particularly appealing to those subscribing to atheistic assumptions, as it eliminated the need for a Creator or divine intervention to explain the origin of the cosmos. By suggesting a universe without a beginning, they could align their scientific observations with a belief in a cosmos operating independently of any external influence.

(*The following is an excerpt from “Does the Universe Paint God Out of the Picture?” by Luke Baxendale. This is part two of four in the book)

Nonetheless, a wave of revolutionary discoveries in cosmology during the 20th century—from the detection of cosmic microwave background radiation to the rise of the Big Bang theory—completely changed how we think about the universe. These breakthroughs overturned the notion of an eternal universe and set the stage for fresh debates about the origin and nature of the cosmos.

One of the most remarkable revelations of the 20th century was the discovery that the universe had a beginning—or at least, that seems to be the case. This idea appeared to be at odds with the framework of naturalistic cosmology, as it suggested an initiating cause for the universe that had to be situated within the universe itself—a notion that seemed paradoxical. In simpler terms, considering the naturalistic perspective that “nature” exists autonomously and encompasses all that exists, it would be unexpected for the universe to have a beginning. Any initiating causes for the universe would have to lie within the universe, a concept that challenges conventional reasoning.

What made scientists rethink the idea of a universe with a clear starting point? It all traces back to the 1920s and an astronomer named Edwin Hubble. Night after night, Hubble gazed through his telescope, studying distant galaxies. What he noticed would change our understanding of the cosmos forever: these galaxies weren’t just sitting still—they were moving away from each other. The universe, it seemed, was expanding.

Hubble’s breakthrough came from observing something called “redshift.” When light from distant galaxies reached Earth, it appeared slightly redder than expected. This wasn’t just a random quirk; it was a clue. Hubble realised this redshift was similar to the Doppler effect—the phenomenon where an ambulance siren drops in pitch as it speeds away. In the same way, light stretches into longer, redder wavelengths when objects move away from us. By measuring how much light from galaxies shifted toward the red end of the spectrum, Hubble could calculate their speed and distance.

When Hubble plotted these measurements, he found a striking pattern: the farther away a galaxy was, the faster it was receding. This discovery suggested that space itself was expanding in all directions, like raisins spreading apart in a rising loaf of bread.

This idea of an expanding universe was a game-changer. If the universe is expanding, scientists wondered, could we trace it back to a single point of origin in time?

Imagine rewinding time like a movie. If everything is moving apart now, then in the past, everything would have been closer together. Extrapolate far enough back, and you arrive at a moment when all matter and energy were compressed into an unimaginably dense and hot state. This idea laid the groundwork for what we now call the Big Bang Theory.

While Hubble provided the observational evidence, Belgian physicist and priest Georges Lemaître connected the dots. In 1927, Lemaître independently derived equations from Einstein’s general theory of relativity that described an expanding universe. He proposed that the cosmos began as a “primeval atom,” a single quantum of energy that exploded outward, creating space and time as we know them. Lemaître’s bold hypothesis was initially met with scepticism—Einstein himself reportedly dismissed it as “too much like creation.” But Lemaître persisted, and his work became a cornerstone of modern cosmology.

The turning point came in 1964 when Arno Penzias and Robert Wilson accidentally discovered the cosmic microwave background (CMB) radiation while working on a radio antenna at Bell Labs. Initially mistaking it for interference caused by pigeon droppings in their equipment, they soon realised they had stumbled upon something extraordinary: faint thermal radiation left over from the Big Bang itself. This “afterglow” of creation provided proof that the universe had emerged from a hot, dense state billions of years ago.

The discovery of the CMB cemented the Big Bang Theory as the leading model for our cosmic origin. It also silenced alternative ideas like Fred Hoyle’s steady-state model, which proposed an eternal universe with no beginning or end. Ironically, Hoyle had coined the term “Big Bang” during a 1949 radio broadcast—meant as a dismissive nickname—but it stuck and became synonymous with one of science’s most profound theories.

[Photo of Lemaître & Einstein]

The Big Bang implies that our universe had a starting point—not just the matter and energy we see around us, but space and time itself. Picture the universe as a balloon. If you deflate it, every point on its surface gets closer and closer together. Now imagine shrinking it all the way down until every point converges into one. That’s essentially what physicists mean when they say the universe had a beginning. As Stephen Hawking once put it, “at some time in the past… the distance between neighbouring galaxies must have been zero.”^[i] This moment of convergence marks not only the start of the universe’s expansion but also, in many ways, the birth of the universe itself.

But don’t picture a traditional explosion, like fireworks lighting up a preexisting night sky. The Big Bang was something far more extraordinary. It didn’t happen in space—it brought space and time into existence. Before this cosmic event, there was no “before” in any meaningful sense because “time” didn’t exist yet. Asking what came before the Big Bang is like asking what lies north of the North Pole—it’s a question that doesn’t fit with how spacetime works. As Einstein showed us, space and time are intertwined in a continuum, so when space began, time began too.

It’s important to note that the Big Bang theory doesn’t tell us why or how the universe came into being; it simply tells us that it had a starting point. The universe wasn’t eternal. It all came into existence in a single moment that we can trace back to billions of years ago. And while we may not yet understand what sparked this incredible event, its echoes are written across the cosmos, from the expansion of galaxies to the faint afterglow of radiation still detectable today.

The Big Bang Theory began to shift the thoughts of many scientists. This new understanding of our origins sent shockwaves through the esteemed halls of science, philosophy, and theology departments. The unsettling revelation for many was that an absolute beginning to our universe suggested the existence of something beyond physical reality, consequently reviving the God hypothesis.

Allan Sandage, renowned as one of the twentieth century’s greatest observational astronomers, stunned his peers by revealing his newly found religious conviction, crediting the scientific evidence of a “creation event” for the significant shift in his worldview. He solemnly declared, “Here is evidence for what can only be described as a supernatural event. There is no way that this could have been predicted within the realm of physics as we know it.”^[ii] In Sandage’s view, something transcending the material realm must have contributed to the universe’s birth. He continued:

“I find it quite improbable that such order came out of chaos. There has to be some organising principle. God to me is a mystery but is the explanation for the miracle of existence, why there is something rather than nothing.”^[iii]

The theological implications of a universe with a beginning were quickly recognised and opposed by many. Physicist Sir Arthur Eddington OM FRS, for example, responded, “Philosophically, the notion of a beginning of the present order is repugnant to me. I should like to find a genuine loophole. I simply do not believe the present order of things started off with a bang… it leaves me cold.”^[iv]

Hawking and Ellis: Extending Singularity Theorems to the Origin of the Universe

Since the late 1960s, further developments in theoretical physics have supplied additional support for the idea that the universe, as well as space and time—or spacetime—had a beginning. Roger Penrose and Stephen Hawking played a central role in making these theoretical advances.

During his PhD research, Stephen Hawking came across the work of physicist Roger Penrose, who was investigating the physics of black holes. Black holes are regions in space where matter is so densely concentrated that even light cannot escape the gravitational pull. Thus, the name “black hole.” Penrose’s theorem showed that when a big enough dying star collapses under its own gravity, it can form a black hole with a singularity at its core—a point where matter is infinitely dense, and the known laws of physics break down. Penrose’s work proved these singularities aren’t just sci-fi stuff. Theoretically, they can happen.

Now, here’s where Hawking had a huge “Aha!” moment. If Penrose’s work could explain singularities in black holes, could the same idea apply to the universe itself? If you rewind cosmic history, the universe’s mass becomes increasingly concentrated, curving spacetime more tightly as you go further back. Hawking theorised that this process would eventually lead to an ultimate limit: an infinitely tight curvature corresponding to zero spatial volume—a singularity. This singularity, he argued, marked not just the beginning of spacetime but also the starting point of the universe’s expansion. Hawking showed that, given such a finite termination point for light and time in the past, “there will be a physical singularity… where the density and hence the curvature (of the universe) are infinite.”^[v]

Building on these ideas, Hawking and Penrose collaborated to develop mathematical proofs linking Einstein’s general relativity to the concept of a cosmological singularity. In 1973, Hawking extended this work alongside physicist George Ellis. Their collective research demonstrated that Einstein’s equations implied a singularity at the very beginning of spacetime—where matter density and spatial curvature reached infinity. This finding provided strong mathematical support for the Big Bang Theory.

So, what does this all mean? As far as we can tell, the universe began from a state of infinite density and curvature—a singularity where spacetime itself came into existence. Interestingly, an infinitely tight curvature corresponds to a radius of zero units in length and thus to zero spatial volume. This suggests a fixed beginning to the universe, as Hawking and Ellis wrote, “there is a singularity in the past that constitutes, in some sense, a beginning of the universe.”^[vi] British physicist Paul Davies captured this idea succinctly in 1978:

“If we extrapolate this prediction to its extreme, we reach a point when all distances in the universe have shrunk to zero. An initial cosmological singularity, therefore, forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity. For this reason, most cosmologists think of the initial singularity as the beginning of the universe. In this view, the Big Bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.”^[vii]

Sometimes people reading about this for the first time get confused and ask if matter or energy can exist without spacetime? The answer seems to be no. Consider an electron—it has properties like mass and charge, but those only make sense within a spatial framework where you can define its position. Similarly, light (or photons) has wavelength and frequency—concepts tied to both space and time. Without spacetime, these entities lose all meaning. Even Einstein’s general relativity describes gravity as the warping of spacetime by mass and energy.

So, the singularity proofs by Hawking, Penrose, and Ellis didn’t just bolster the Big Bang Theory—they pointed to something even more profound: that everything we know emerged from nothing. Not “nothing” as in empty space (which is still something), but actual nothingness—nothing spatial, temporal, material, or physical. It’s a strange idea because nothingness, by definition, can’t explain anything; it has no power to cause anything. It’s a mind-bending idea because nothingness has no properties or power to cause anything. Yet somehow, from this void came everything—the stars, galaxies, and even us. It’s a concept so counterintuitive that it challenges our very ability to comprehend it fully. But this is precisely what the mathematics suggests: our universe had a definitive beginning.

General Relativity and Quantum Mechanics: A Barrier for Singularity Theorems

How confident can we be in the Big Bang Singularity theory? Well, here’s where things get a little complicated. General relativity, one of the most well-tested and reliable theories in modern physics, excels at describing the big everyday stuff—planets, stars, galaxies—but it begins to falter when we zoom way, way in, down to the smallest levels of reality, the world of quantum mechanics.

Quantum mechanics is the science of the teeny-tiny world, the subatomic particles that make up everything around us. But this world is beyond weird. Light and electrons, for instance, can behave as both particles and waves depending on how they’re observed. Energy can fluctuate unpredictably. It’s a world of possibilities and probabilities, nothing like the neat and smooth spacetime described by general relativity.

The problem? These two worlds—big and small—don’t play nicely together. General relativity doesn’t account for quantum effects, and it’s not clear how quantum mechanics connects to the large world we experience. Bridging this gap is one of physics’ biggest challenges.

Many physicists believe that solving this problem will require a quantum theory of gravity. Such a theory would combine the large-scale elegance of general relativity with the bizarre, microscopic world of quantum mechanics. If we ever crack this code, it could revolutionise our understanding of the universe’s earliest moments and might even refine—or completely replace—the idea of a singularity at the beginning of time.

But here’s the thing: no one has figured out this unified theory yet. It’s one of the biggest unsolved puzzles in physics. And if history is any indication, scientific progress tends to raise more questions than answers, so there’s unlikely to be a single “final theory” that explains everything.

For now, we’re left with a paradox: general relativity works brilliantly on cosmic scales but falters when we rewind the clock to the universe’s first fraction of a second. Stephen Hawking, Roger Penrose, and George Ellis highlighted this limitation in their work on the cosmological singularity. They noted that general relativity allowed them to trace the universe’s history back with confidence only to a point where its radius of curvature measured somewhere between a trillionth of a centimetre and a billion trillion trillionth of a centimetre. At such an incredibly tiny scale, it’s understandable why they considered the universe to be, for all practical purposes, a spatial singularity. As they put it, “such a curvature would be so extreme that it might well count as a singularity.”^[viii]

So, while the Big Bang Singularity theory is a strong framework that implies a beginning to the universe, it remains partially incomplete without quantum mechanics in the mix.

Doubts From Inflation Cosmology

It’s unsettling to think that the universe—this vast, seemingly endless expanse—actually had a beginning. That’s why many scientists over the years have tried to challenge the idea of a cosmic starting point. One of the earliest and most intriguing alternatives to the Big Bang Theory came from astrophysicists Hermann Bondi, Thomas Gold, and Fred Hoyle. They proposed the “Steady State Model,” a bold theory that envisioned the universe as eternal, with no beginning and no end.

The Steady State Model embraced the observation that galaxies are moving away from each other—a cornerstone of the Big Bang Theory—but offered a clever twist to avoid a beginning. According to this idea, as the universe expands and galaxies drift apart, new matter is continuously created to fill the gaps. This constant creation of matter would form new galaxies, keeping the overall density and structure of the universe unchanged over time. In essence, they imagined a kind of cosmic recycling system that had always been in motion, sidestepping the need for a definitive starting point.

For a while, this idea seemed like a plausible alternative. But by the 1960s, mounting observational evidence began poking holes in it. For one, if the Steady State Model were correct, galaxies of all ages should be evenly distributed throughout the universe. Instead, astronomers found that younger galaxies are clustered farther away—evidence that points to an evolving universe rather than one that’s eternally unchanging.

Another attempt to sidestep the universe’s origin was the “oscillating universe” model, championed by Polish physicist Jaroslav Pachner. In essence, this model suggests that the universe undergoes endless cycles of expansion and contraction, or “big bangs” and “big crunches.” The universe expands from a singularity, as described by the Big Bang, but eventually slows down and contracts due to gravity, collapsing back into a singularity in a “big crunch.” Then, through some unknown mechanism, another “big bang” occurs, and the cycle repeats indefinitely.

However, the oscillating universe model lost favour primarily because of the pesky issue of entropy. The second law of thermodynamics dictates that entropy, or disorder, always increases in a closed system like the universe. In an oscillating universe, this means each cycle would have more entropy than the last, causing each subsequent cycle to last longer. Think of a bouncing ball: each bounce is lower and shorter than the one before it, as energy is lost. Similarly, the oscillating universe’s cycles would expand and contract at progressively slower rates.

Running this model in reverse, earlier cycles would become increasingly shorter, eventually reaching an impossible zero. This, combined with other evidence like the observed acceleration of the universe’s expansion, led scientists to largely abandon the oscillating universe model in favour of the inflationary Big Bang model. Besides, even if true, this model would only push the first origin back a finite number of universe cycles, leaving the fundamental question of ultimate origin unanswered.

Nevertheless, other advancements in theoretical physics and cosmology soon emerged, quickly shaking up the standard Big Bang model and casting doubt on whether singularity theorems really made sense in describing the universe’s earliest moments. But here’s the twist: those same developments eventually brought physicists full circle, pointing to the idea that the universe likely did have a beginning after all. This twisty tale begins in the 1980s with the birth of inflationary cosmology.

During this time, physicists like Alan Guth, Andrei Linde, and Paul Steinhardt, proposed that shortly after the Big Bang, the universe went through a supercharged growth spurt called inflation. Imagine an “inflation field” acting like a cosmic pressure, causing space to expand at an unbelievable rate.

Inflationary cosmology was an extension to the Big Bang model that resolved some major head-scratchers. For instance, it addressed the horizon problem, which questioned how distant regions of the universe shared similar properties despite the absence of any mechanism for them to communicate and exchange information, thus explaining the observed homogeneity and isotropy of the cosmos. Furthermore, the rapid expansion of space during inflation also flattened any large-scale spatial curvature, making the universe appear remarkably flat on observable scales.

As originally proposed by Alan Guth, the concept of inflationary cosmology assumed a beginning to the universe, after which space would undergo a brief yet rapid expansion. However, subsequent developments in the field led to the emergence of a more complex theory known as “eternal chaotic inflation.” This idea envisions not just a single beginning, but an infinite number of beginnings, giving rise to a vast multiverse.

Eternal chaotic inflation, championed by Andrei Linde, imagines our universe as just one “bubble universe” among countless others in an eternally expanding multiverse. Inflationary cosmology proposes that our universe experienced a brief, rapid expansion shortly after the Big Bang. Eternal chaotic inflation takes this idea further by suggesting that this expansion process is not a one-time event, but rather something that happens continuously, resulting in a never-ending cascade of new universes. Inflationary cosmologists envisioned inflation as having operated for an indefinitely long time in the past and continuing indefinitely into the future. They therefore anticipated that the wider inflation field will spawn an endless number of other universes as it decays in local pockets of an ever-growing volume of space. This happens because the energy field responsible for the rapid expansion, known as the “inflation field,” experiences random fluctuations. These fluctuations cause some regions of space to expand and form new bubble universes, each with its own unique properties and distinct laws of physics. In essence, eternal chaotic inflation presents a picture of a vast, infinitely expanding multiverse filled with numerous bubble universes, including our own. We will come back to this later in the book.

Eternal chaotic inflation models challenge the idea of a single cosmic beginning and a cosmological singularity, distinguishing them from the standard inflation model. These models introduce the idea of an eternally existing multiverse—suggesting that the universe might not have a single starting point or an ultimate end at all. According to Linde’s theory, this framework implies that the cosmos has always had a past and will always have a future.

In this framework, our universe emerged from a quantum fluctuation in a pre-existing region of the spacetime continuum. Linde argues that “each particular part of the [multiverse] may stem from a singularity somewhere in the past, and it may end up in a singularity somewhere in the future.”^[ix] While some parts of the multiverse may stop expanding and contract, inflation ends at different times in different places. Consequently, there are always regions of the multiverse that continue to inflate, with universes like ours being eternally produced.

Even though eternal chaotic inflation seemed to dismiss the need for a definitive beginning, it inadvertently pushed theoretical physics towards an even stronger argument for a beginning—one that stands regardless of what ultimately becomes of inflationary cosmology.

In the early 1990s, the popularity of eternal chaotic inflation led physicists Arvind Borde and Alexander Vilenkin to question whether the inflation field could stretch infinitely into the past. They aimed to determine whether the inflation field could have operated infinitely far into the past—whether it could be “past eternal” as they termed it. Within a decade, Borde, Vilenkin, and Alan Guth (one of the original proponents of inflation) arrived at a startling conclusion: the universe must have had a beginning, even if inflationary cosmology is correct.

BGV Theorem

Back in 2003, physicists Arvind Borde, Alan Guth, and Alexander Vilenkin dropped a bombshell with their paper, “Inflationary spacetimes are not past-complete,” introducing the Borde-Guth-Vilenkin (BGV) theorem. The core idea? If a universe (or any spacetime) has been expanding on average throughout its history, then it cannot stretch infinitely into the past. In simpler terms, an expanding universe like ours must have had a beginning.

What makes the BGV theorem so intriguing is that it doesn’t rely heavily on detailed assumptions about the universe, such as the specific laws of physics or the nature of energy within it. Instead, the theorem is rooted in the geometry of spacetime itself, focusing on something fundamental: the paths that particles and light follow, known as geodesics. It’s a bit like studying the structure of a highway system without needing to know the types of cars driving on it. The theorem asks: how do these paths behave over time in a cosmos that’s expanding?

At the heart of the BGV theorem lies the concept of the average Hubble parameter (Hav), which measures how fast the universe has been expanding over time. The theorem states that in any universe where this average expansion rate is positive (Hav > 0), spacetime must be “geodesically incomplete” in the past. This means the paths particles or light follow simply can’t be extended infinitely backward in time. The unavoidable implication? An expanding universe, like ours, must have a starting point—a kind of cosmic boundary where it all began.

The beauty of the BGV theorem lies in its broad applicability. It doesn’t depend on the specifics of our universe, like its energy content or the intricate workings of general relativity. Instead, it offers a sweeping insight into the nature of expanding spacetimes, forcing us to confront the likelihood that the universe had a definitive starting point.

To help you understand, imagine a group of hikers exploring a network of trails in a forest. Each hiker represents a geodesic (the path followed by a freely falling particle) in spacetime. The trails represent the possible paths that the hikers can take through the forest.

Now, suppose that the forest has a rule: no matter which trail a hiker takes, they must always be moving uphill or on a flat surface. In other words, they can never go downhill. This rule corresponds to the condition of expansion or inflation in the BGV theorem.

The BGV theorem essentially states that if this “uphill or flat” rule holds throughout the entire forest, then there must be a starting point from which all the hikers began their journey. In other words, the network of trails cannot extend infinitely far into the past.

If the trails could extend infinitely far back, then at least one hiker would have been walking downhill forever, violating the “uphill or flat” rule. Therefore, the existence of a beginning or a starting point for all the hikers (and hence, all the trails) is inevitable.

In the context of the universe, the “uphill or flat” rule corresponds to the condition of expansion or inflation. The BGV theorem shows that if this condition holds throughout the history of the universe, then there must have been a beginning, a point beyond which spacetime cannot be extended further into the past.

This analogy, while not perfect, gives a sense of the key idea: the BGV theorem provides strong evidence for a beginning of the universe, even in alternative models of inflation. Borde, Guth, and Vilenkin have shown that all cosmological models featuring expansion—including inflation cosmology, multiverses, and the oscillating and cosmic egg models—are subject to the BGV theorem. Consequently, Vilenkin argues that evidence for a beginning is now almost inescapable. As he explains: “With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is no escape; they have to face the problem of a cosmic beginning.”^[x]

In conclusion, the Borde-Guth-Vilenkin theorem is a fascinating breakthrough in cosmology, pointing to a beginning of the universe based on the principles of spacetime expansion. While it doesn’t reveal the full story of the universe’s origin, it places significant limits on models of the universe.

The Impossibility of an Infinitely Old Universe

The question of how the universe began isn’t just a scientific mystery—it’s also a deeply philosophical one. One fascinating philosophical argument challenges the possibility of an infinite past by suggesting that an actual infinity of events is impossible to complete. Here’s how that works…

Think about counting numbers: you start with 1, then 2, then 3, and keep going. No matter how long you count, you’ll never actually reach infinity. You’re always adding one more, which means the total number is growing but still finite. This is called a “potential infinity”—it’s never-ending in theory, but it’s not something you can ever fully realise. Counting to infinity is like trying to climb out of a pit with walls that stretch endlessly upward. No matter how far you climb, the top is always out of reach.

Now, let’s apply this idea to the universe. Imagine time as a timeline, with the present moment marked as zero. Each day that’s passed is a point on the line: yesterday is -1, the day before is -2, and so on. If the universe had no beginning, the timeline would stretch infinitely into the past. But here’s the catch: if there were an infinite number of moments before now, how could we have ever arrived at today? It would be like trying to count from negative infinity to zero—an impossible task. Philosophically, it doesn’t make sense. If it truly took forever to get to this moment, we simply wouldn’t be here.

To bring this idea to life, let’s use a thought experiment: Imagine a soldier about to fire their weapon. Before pulling the trigger, they need permission from the soldier behind them. But that soldier also needs approval from the one behind them—and so on, in an endless chain of soldiers. If no one is the first to give permission, would the initial soldier ever fire? Of course not. This highlights the problem with infinite regress: if an endless sequence of steps were required to reach the present, we’d never get here. That’s why the concept of an infinite series of past events doesn’t quite hold up—it’s just not workable.

The famous mathematician David Hilbert put it this way, “The infinite is nowhere to be found in reality. It neither exists in nature nor provides a legitimate basis for rational thought… the role that remains for the infinite to play is solely that of an idea.”^[xi] While “infinity” is a useful concept in mathematics and helps solve certain equations, it doesn’t show up in the physical universe as we know it. This is one reason we should be sceptical of the idea that the universe could be infinitely old.

The Cosmic Dawn: Naturalism’s Conundrum

Okay, lets recap. We’ve all looked up at the cosmos and wondered: did it all start somewhere? Interestingly, both philosophical thought and scientific inquiry nudge us toward a similar idea: the universe likely had a beginning. Here are the key arguments for this:

1. The Second Law of Thermodynamics: According to this law, the amount of useful energy in the universe is irreversibly decreasing. If the universe were infinitely old, all its useful energy would have been exhausted by now. However, since there are still abundant sources of useful energy (such as the sun), it is logical to conclude that the universe is finite in age. This means that there was a starting point when the universe’s energy was introduced from an outside source that precedes the laws of thermodynamics. If the universe had existed throughout an actual infinite past, it would have reached an equilibrium state an infinite number of days ago, which clearly has not occurred.
2. The Big Bang Theory: According to this theory, the universe began expanding from an extremely dense and hot state. Evidence such as the observed redshift of distant galaxies and the cosmic microwave background (CMB) suggests that the universe was once much smaller and denser, indicative of a beginning.
3. The Hawking-Penrose-Ellis Singularity Theorems: These theorems provide strong evidence for a beginning of the universe. They demonstrate that under general conditions, the universe must have originated from a singularity.
4. The Borde-Guth-Vilenkin (BGV) Theorem states that any universe that has been, on average, expanding throughout its history cannot be past-eternal and must have a boundary in the past. This boundary is interpreted as the starting point of spacetime, implying that time itself had a beginning. Since time and space are interwoven in both general relativity and quantum gravity theories, a beginning of time would indeed suggest a beginning of space as well.
5. The philosophical argument on the impossibility of traversing an actual infinite: As previously discussed, the notion of an actual infinite cannot be applied to the real world, as it leads to contradictions and defies logical comprehension. A philosophical argument for the universe’s beginning is grounded in the impossibility of traversing an actual infinite series of events.

So, the Big Bang singularity model, along with theorems like BGV, strongly suggest the universe had a definite beginning—a “creation event.”

Now, here’s a twist for those who think the universe is all there is—the foundation of the naturalistic worldview: If the universe is truly all-encompassing, then nothing outside of it could have caused it. This creates a problem for naturalism because it relies on the very thing it’s trying to explain: the origin of nature itself. In other words, trying to use naturalistic explanations to account for the beginning of the universe is like trying to lift yourself off the ground by pulling on your own shoelaces. For this reason, it’s reasonable to think that any explanation for how the universe began must go beyond naturalism and point to something outside the natural world—it must be non-naturalistic in nature.

This idea gains traction with the Hawking-Penrose Singularity theorem. The theorem suggests that, according to general relativity, the universe likely originated from a singularity—a state of infinite density and zero spatial volume in which classical physics breaks down. Space, time, matter, and energy are thought to have emerged as the universe expanded from this initial point. This challenges materialistic explanations, as material particles and energy fields could not subsist before spacetime itself. There was no “before” and no physical “thing” that could have caused it to happen. This idea mirrors the theological concept of creatio ex nihilo, or “creation out of nothing material.”

If the universe had a beginning, it’s only natural to wonder what caused it. That curiosity leads us to consider that the universe’s origin might be rooted in a non-material or transcendent reality, a central tenet in many religious and philosophical traditions throughout human history.

Some proponents of naturalism remain hopeful that future scientific advancements will eventually explain the universe’s origins within a naturalistic framework. However, this optimism amounts to a leap of faith—there’s no way to predict if or when such breakthroughs might occur or whether they’ll provide a clear, consistent naturalistic explanation. If the evidence suggests that naturalism is insufficient to explain the universe’s origin, placing hope in the possibility that future scientific discoveries will eventually support a naturalistic perspective is simply not enough. Instead, it’s more reasonable to consider other explanations that, while stepping outside the naturalistic view, remain firmly rooted in the evidence we have at hand. Relying too heavily on yet-to-be-made discoveries to support naturalistic assumption risks falling into the trap of an argument from ignorance. This kind of reasoning, often criticised in religious contexts, is equally problematic in scientific discourse.

The Resurgence of the God Hypothesis

The Judeo-Christian tradition has long held the belief that our universe was created by God, so theistic scientists naturally expected to find evidence of its beginning. Naturalism’s a priori dismissal of a non-natural cause for the universe made the idea of its eternal existence an appealing proposition. Yet, over the past century, the pendulum of evidence has swung back in favour of theistic expectations. Does this hint at something greater? Could it support the idea of a Creator? These are big questions that deserve careful thought. Let’s avoid rushing to hasty conclusions, but at the same time, let’s not be too quick to dismiss the possibility.

Firstly, let’s consider the initial argument put forward by Stephen Meyer:^[xii]

1. Major Premise: A Judeo-Christian belief in a divine creator implies the universe had a beginning
2. Minor Premise: We have evidence that the universe had a beginning
3. Conclusion: We have reason to think that the Judeo-Christian view of the origin of the universe and its affirmation of a divine creator may be true

This syllogism suggests that the Big Bang Theory provides epistemic support, although not deductive proof, for the hypothesis of Judeo-Christian theism. It’s a fascinating start, but we can delve even deeper.

The cosmological argument for the existence of a creator was first proposed by one of the greatest medieval polymaths, Al-Ghazali, a twelfth-century Muslim from Persia. He argued that the universe must have a beginning, and since nothing begins to exist without a cause, there must be a transcendent creator of the universe. We can summarise his argument in three steps:

1. Whatever begins to exist has a cause
2. The universe began to exist
3. Therefore, the universe had a cause

The argument is intriguing, but it’s not without flaws. I believe we can refine and expand upon it, but first, let’s break it down and analyse each step.

Premise one: Whatever Begins to Exist Has a Cause

The cosmological argument starts with a premise that feels like common sense—it’s something most of us instinctively agree with. The idea of something emerging from absolute nothingness not only seems like magic, it’s also a breach of fundamental logic. It’s akin to imagining horses or houses materialising from the ether, conjured without reason or explanation—it defies our everyday understanding of how things come to be.

Suggesting that the universe simply popped into existence out of nowhere, or that the Big Bang happened without any underlying reason, is as baseless as saying coconuts drop from trees “just because.” It’s a scientific inconsistency to accept reasons and causes for every phenomenon but exclude the universe’s own existence from this reasoning.

Picture a line of dominoes falling one after another. When you see this, it’s easy to assume something must have knocked over the first one to set the chain in motion. This simple domino effect illustrates a universal idea we all understand: every effect must have a cause. Such everyday observations reinforce the logic behind the first premise of the cosmological argument.

Continuing from the idea that every effect has a cause, it’s natural to approach extraordinary claims, like miracles, with a healthy dose of scepticism. However, there’s a glaring inconsistency if a sceptic dismisses something like the virgin birth of the son of God as implausible, yet readily accepts the idea of the virgin birth of the universe. Even if the notion of divine creation seems far-fetched to some, the alternative—an uncaused beginning of everything—is arguably even more challenging to rational understanding.

Premise Two: The Universe Began to Exist

The second premise, which we have already established, is that the universe began to exist. We have derived this view from general relativity and the development of the Big Bang Theory, supported by the Second Law of Thermodynamics, the Hawking-Penrose-Ellis Singularity Theorems, the Borde-Guth-Vilenkin (BGV) Theorem, and a philosophical argument regarding the impossibility of traversing an actual infinite number of events.

Premise Three: The Universe Had a Cause — Exploring its Characteristics

In the Kalam Cosmological Argument, the third premise logically follows from the first two points. This argument employs a syllogism, a logical structure consisting of two premises leading to a conclusion. In this case, the truth of the first and second premises compels us to conclude that the universe had a cause. If everything that begins to exist has a cause, and if the universe began to exist, then it logically follows that the universe must have a cause for its existence.

But not everyone agrees with this line of thinking. Some big names, like atheist Daniel Dennett and the late physicist Stephen Hawking, have proposed a bold idea: what if the universe caused itself? In other words, what if the universe is both the question and the answer to its own existence? It’s an intriguing concept, almost poetic in its ambition.

At first glance, their arguments seem profound. Yet, when we pause for straightforward, logical thinking, cracks start to appear. The concept of self-creation is a bit like a snake trying to bite its own tail—it’s a logical loop. For something to create itself, it needs to exist before it exists… Consider the example where “X” creates “Y”: we assume “X” exists in order to bring “Y” into existence. So, if we say “X” created “X,” we assume “X” exists in order to bring “X” into existence, which is logically incoherent. The idea of something fully creating itself is a logical impossibility. The claim that “X” created “X” effectively says, “Allow me to assume ‘X’ already exists, and I’ll explain how ‘X’ then came into existence in a world in which ‘X’ already existed.”

Now, let’s take Al-Ghazali’s argument a step further and delve into a more intriguing aspect: the nature of the universe’s cause. Specifically, let’s focus on the third premise and ask—what kind of cause are we talking about? What attributes must this cause have? Could this cause suggest the existence of a higher intelligence or even a divine being? Or might it resonate more with non-theistic perspectives? To get closer to an answer, we need to ask a fundamental question: what properties must the universe’s cause possess?

First off, it would be reasonable to assume an uncaused first cause. This is because as an infinite series of causes—each having an explanation in another cause—would result in no ultimate or sufficient explanation for the existence of the series as a whole. Even if the cause of this spacetime continuum itself has a cause, the impossibility of an infinite regress of causes necessarily leads us eventually to an uncaused cause. An uncaused first cause eradicates the untenable notion of an infinite regress and presents a more cogent solution, accounting for the origin of the causal chain and the existence of the universe without introducing additional explanatory complications.

Now, you might think that labelling the first cause as “uncaused” as a bit too convenient, a way to sidestep the kind of scepticism we apply elsewhere. Fair point. The idea of an uncaused first cause is admittedly hard to grasp. But here’s the crux: it still holds up better logically and philosophically than an endless chain of causes. Admittedly, like everyone in this field, we are choosing the lesser of two mysteries, but we are forced to opt for the option that, while challenging, offers a more likely explanation.

Let’s consider a second point: the initial cause of the universe must be something entirely separate from and outside the universe itself. This conclusion feels intuitive when you think about it. After all, the idea of something creating itself is a logical impossibility—it’s like trying to imagine a book writing itself. Everything in the physical world is either an effect or the result of something else, not entirely its own cause.

Since causes are distinct from their effects, the universe’s cause must also be distinct from it. Since the universe is made up of spacetime, matter, and energy, then the cause of the universe would seem to lie beyond these dimensions—i.e. transcendent. This leads us to expand our definition of the universe to include anything that began to exist and needed a cause, possibly even what we term the multiverse.

When we think about physical causes or scientific laws, we’re already presupposing the existence of spacetime and matter. But the cause of the universe couldn’t have been a physical law within some higher-dimensional space because, as the BGV theorem proposes, spacetime would need its own origin. The logical deduction? The ultimate cause must be beyond spacetime, matter, and energy, and not be bound by the laws of nature. This points to something timeless, spaceless, and unimaginably powerful—a concept that, while abstract, is still reasonable.

You might wonder, “Could this ‘first cause’ be an eternal, law-like force?” It’s a reasonable question, but in principle, scientific laws don’t create things; they simply describe how existing systems operate. Think of it this way: the laws of mathematics can show that if I have $5 in my pocket and earn another $5, I’ll have $10. However, mathematics itself doesn’t create the $10 or place it in my pocket. Later in the book we will explore this notion in greater depth.

Also, if the first cause of the universe were merely an impersonal set of necessary and sufficient conditions, it would face a significant problem: such a cause could not exist without immediately producing its effect. A deterministic sufficient condition, once present, inevitably leads to a certain outcome. Therefore, if the first cause of the universe were such conditions, their effect—the universe—must also be present whenever these conditions are. This would imply an eternal universe, which contradicts the understanding that the universe had a beginning, including time itself.

This points us toward an important conclusion: the first cause must be capable of existing independently of its effect. It cannot be a mechanical or deterministic precursor that automatically triggers its outcome. While some have hypothesised non-deterministic precursors like quantum foam, issues such as those raised by BGV theorem still apply. This nudges us away from a mechanical, condition-bound first cause towards something more dynamic and intentional.

If the first cause is not an impersonal, deterministic condition, it might have the ability to act freely, implying volition or will. For the universe to begin to exist, the first cause must have had the discretion to initiate creation. An impersonal set of conditions lacks this discretion; if the conditions are met, the effect must follow. By contrast, a volitional being (a being with a will) can choose to act, existing without any effect and possessing the capacity to decide to create.

This leads us to contemplate the “will” in relation to consciousness. Could it be that an ultimate consciousness existed without the universe? The idea of a volitional agent—a conscious being with the capacity to choose—offers a framework for understanding how the universe might have come into existence. After all, we, as conscious beings with free will, often bring new things into existence through deliberate choice. This relatable experience lends plausibility to the notion that something like a conscious mind could have initiated the universe in a similar way.

Of course, this hypothesis raises new questions too—particularly about the nature of consciousness itself, which is just another one of science’s biggest mysteries. But even with these challenges in mind, introducing the concept of an independent cause—something outside physical laws and preexisting conditions—offers a worthwhile perspective. It suggests that intentionality might lie at the very heart of creation itself.

The notion of a volitional agent provides a fresh way to address the question of how the universe came into existence. Unlike impersonal forces or deterministic mechanisms, an agent with free-will could deliberately initiate a sequence of cause and effect without relying on prior material states. This perspective bypasses the complications of an infinite regress of causes or an eternal chain of events—both of which conflict with the prevailing cosmological understanding that the universe had a beginning. In conclusion, an examination of the properties of the original cause suggests that it is:

• Uncaused;
• Immaterial;
• Timeless;
• Spaceless;
• Immensely powerful;
• Volitional;

These attributes appear to hint not just at any transcendent cause, but one that closely aligns with the concept many have of God—the uncaused, spiritual, transcendent, immensely powerful intelligence that is the ultimate source of all being. Christian theology views the physical world as the creation of an ultimate Mind.

One possible way to conceptualise this is to envision God existing alone without the universe, as changeless and timeless. God’s free act of creation is a temporal event, simultaneous with the universe’s coming into being. Thus, God is timeless without the universe and in time with the universe.

Admittedly, grasping these concepts can be challenging. While the revised cosmological argument isn’t exactly airtight, it’s more about exploring what feels most probable, not nailing down absolute certainty. In that sense, I find this argument more persuasive than purely naturalistic explanations. It ties into two key ideas: the universe’s beginning aligns with what we might expect if God exists, and the Judeo-Christian depiction of God resonates well with the qualities needed for the universe’s initial cause.

It’s interesting to note that several prominent scientists have made similar observations. Arno Penzias, the Nobel laureate who discovered cosmic background radiation, put it this way regarding the Big Bang: “The best data we have are exactly what I would have predicted, had I nothing to go on but the first five books of Moses, the Psalms, and the Bible as a whole.”^[xiii] Similarly, George Smoot, another Nobel Prize winner, remarked on the Big Bang ripples observed by NASA’s COBE Satellite, asserting that “there is no doubt between the Big Bang as an event and the Christian creation notion of creation from nothing.”^[xiv] Quantum chemist and Nobel Prize nominee Henry F. Schaeffer III also concluded that “A Creator must exist. The Big Bang ripples and subsequent scientific findings are clearly pointing to an ex nihilo creation…”^[xv]

These observations recall the words of NASA astronomer Robert Jastrow, who wrote:

“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.”^[xvi]

The Atheist’s Query: “But Where Did God Come From?”

Wisdom includes the courage to question your own beliefs. It’s about being honest with yourself and staying open to the idea that what you think you know is almost certainly incomplete—or even wrong. This becomes especially crucial when we tackle big, thorny questions, like the existence of God. After all, the concept of an uncaused, timeless, and immaterial being presents its own set of unique concerns and challenges.

One frequent challenge, often voiced by figures like Richard Dawkins and Christopher Hitchens, questions the origin of God, especially when considering the cosmological argument: if everything requires a cause, then surely God must also require a cause? This leads to the question, “Where did God come from?” Invoking God as the explanation for the universe’s origin doesn’t resolve the issue but merely pushes the question back a step. Instead of solving the mystery, it creates a new one: who or what caused God?

It’s important to be precise here. The argument isn’t that everything needs a cause, but rather that everything that begins to exist needs a cause. Since we understand the universe had a beginning, and considering that a cause transcends its effect, it follows that its necessary cause, existing outside our temporal reality, isn’t subject to these limitations. This distinction opens the door to the concept of an uncaused, eternal being, which in this context, many of us identify as God.

Something outside of time would be eternal and thus would not require a cause for its existence, as it never came into being. If God is without beginning or end (i.e., transcendent), then He did not have to begin, and without a beginning, He did not need a cause.

Now, I have spent a lot of time wondering about God’s relationship with time. Instead of thinking about God as someone who has been around forever, I think it’s more accurate to say God exists outside of time altogether. Thomas Aquinas argued that time, whether short or long, doesn’t apply to God. He’s not just a long-lasting being or one that’s been around for eons. God stands beyond such measurements. God isn’t just an everlasting being. It’s hard, maybe even impossible, for our minds to fully grasp this. While we are bound by the past, present, and future, for God, every moment is like a “present”, and so there is no moment, whether now or in the future, which isn’t present to God.

The key idea is that God operates outside the rules of cause and effect that govern the universe. While everything within the universe depends on something else for its existence, God is different—He is what philosophers call a necessary being. This means that God’s existence isn’t dependent on anything else; He simply is. This concept addresses the challenge of infinite regress—the endless chain of “What caused that? And what caused that?” With God, having no beginning, such questions don’t apply. Asking about His origin misses the point. He exists outside the framework of time and causality. This is part of the mystery of God.

The Doctrine of Creation

Throughout history, many classical philosophers believed that a transcendent reality underpins our universe. Despite their different schools of thought, they converged on the idea that the universe couldn’t explain itself. They suggested that the existence of physical laws implies a Mind—perhaps what many call God—that formulated those laws and ensures the physical realm adheres to them.

Christianity doesn’t rely on fantasy to address life’s big questions. Take Moses, the Hebrew leader, for example. He warned his people against worshipping created things, like other gods or celestial bodies. Similarly, the biblical prophets found it absurd to bow down to the sun, the moon, or any part of the universe while ignoring the Creator who made it all—“The fool says in his heart, ‘There is no God.’” (Psalm 14:1)

The Christian doctrine of creation challenges many popular philosophical ideas. For instance, it questions the concept of eternal dualism, which suggests the perpetual existence of both matter and spirit, and disputes the ideas of philosophical materialism, which claims that the physical elements of the universe are the sole components of existence. This doctrine also challenges the notion of panentheism—the belief that everything is a manifestation of God—as well as various New Age philosophies and witchcraft that echo this idea. Scriptural accounts of creation, especially in the Book of Genesis, portray a universe crafted with benevolent intentions, contradicting Gnostic beliefs and certain ascetic practices that improperly renounce worldly pleasures as antithetical to a godly life.

The doctrine of creation also shapes how we view our role in the universe. Since the universe is God’s creation and not divine in itself, it’s not something to be worshipped. This perspective counters many New Age, Wiccan, and pagan beliefs. Instead, we are called to responsibly govern and care for nature, acting as stewards of God’s creation. This is exemplified in Genesis 1:28, where God commands humanity to populate and manage the earth responsibly. This directive also opposes extreme forms of environmentalism that place animal or elemental interests above human needs. In conclusion, it’s worth noting that the origin of the universe presents a fascinating puzzle that appears to undermine atheistic and naturalistic perspectives, subtly hinting at the potential validity of what we may call the “God Hypothesis.” To be clear, this isn’t about asserting irrefutable proof of a deity’s existence—far from it, given the myriad of unanswered questions that remain. Rather, it’s about suggesting that, when placed side by side with atheistic naturalism, theistic interpretations seem to fit better with the cosmological evidence. This isn’t to say that theism has all the answers, but it does seem to resonate more closely with the cosmological evidence we currently have.

^[i] Hawking, S. A Brief History of Time, 49.

^[ii] Meyer, S.C. Quotes are from transcription of a private film of Sandage’s remarks at “Christianity Challenges the University: An International Conference of Theists and Atheists,” Dallas, Texas, February 7-10, 1985.

^[iii] Sandage, A.R. As quoted in Wilford, J.N. ‘Sizing up the Cosmos: An Astronomers Quest’, New York Times (12 Mar 1991), C10.

^[iv] Luminet, J.-P. “Lemaître’s Big Bang,” lecture given at Frontiers of Fundamental Physics 14, Aix Marseille University, Marseille, France, July 15-18, 2014, 10. Retrieved from https://arxiv.org/ftp/arxiv/papers/1503/1503.08304.pdf (accessed November 14, 2020).

^[v] Hawking, S. ‘Properties of Expanding Universes’, 105.

^[vi] Hawking, S., & Ellis, G. The Large Scale Structure of Space-Time, xi.

^[vii] Craig, W.L. (pp. 101-102). Quoting Davies, P.C.W. “Space-time Singularities in Cosmology,” in The Study of Time III, eds. Frase, J.T., Lawrence, N., & Park, D. (Berlin: Springer, 1978), 78-79.

^[viii] Hawking, S., & Ellis, G. The Large Scale Structure of Space-Time, 96, 363.

^[ix] Linde, A. (November 1994). The Self-Reproducing Inflationary Universe. Scientific American.

^[x] Vilenkin, A. Many Worlds in One. (2006). New York: Hill and Wang, 176.

^[xi] Hilbert, D. On the infinite. Mathematische Annalen (Berlin), 95, 161-190 (1926).

^[xii] Meyer, S.C. The Return of the God Hypothesis: Three Scientific Discoveries Revealing the Mind Behind the Universe – January 1, 2019, 244.

^[xiii] Browne, M.W. Clues to Universe Origin Expected. New York Times, March 12, 1978.

^[xiv] Smoot, G. (1993). Wrinkles in Time.

^[xv] Schaeffer III, H.F. Science and Christianity: Conflict or Coherence?

^[xvi] God and The Astronomers (1978). Currently published by Reader’s Library and updated as recently as 2000.