What Happened Before the Big Bang?
By Paul Davies
It is often said that science cannot prove the existence of God. Yet science does have value in theological debate because it gives us new concepts that sometimes make popular notions of God untenable. One of these concerns the nature of time.
Many people envisage God as a sort of cosmic magician who existed for all eternity and then, at some moment in the past, created the universe in a gigantic supernatural act. Unfortunately, this scenario raises some awkward questions. What was God doing before he created the universe? If God is a perfect, unchanging being, what prompted him to act then rather than sooner?
The fifth-century theologian St. Augustine neatly solved the problem by proclaiming that the world was made with time and not in time. In other words, time itself is part of God's creation.
To make sense of Augustine's concept, it is necessary to place God outside of time altogether, and the notion of a timeless Deity became official church doctrine. However, it is not without its own difficulties. How can a timeless God be involved with temporal events in the universe, such as entering into human history through the Incarnation?
Today, religious people like to identify the creation with the Big Bang of scientific cosmology. So what can we say about the nature of time in the scientific picture?
Albert Einstein showed us that time and space are part of the physical world, just as much as matter and energy. Indeed, time can be manipulated in the laboratory. Dramatic time warps occur, for example, when subatomic particles are accelerated to near the speed of light. Black holes stretch time by an infinite amount. It is therefore wrong to think of time as simply "there," as a universal, eternal backdrop to existence. So a complete theory of the universe needs to explain not only how matter and energy came to exist, it must also explain the origin of time.
Happily, Einstein's theory of relativity is up to the job. It predicts a so-called "singularity" at which time abruptly starts. In the standard Big Bang scenario, time and space come into being spontaneously at such a singularity, along with matter.
People often ask, What happened before the Big Bang? The answer is, Nothing.
By this, I do not mean that there was a state of nothingness, pregnant with creative power. There was nothing before the Big Bang because there was no such epoch as "before." As Stephen Hawking has remarked, asking what happened before the Big Bang is rather like asking what lies north of the North Pole. The answer, once again, is nothing, not because there exists a mysterious Land of Nothing there but because there is no such place as north of the North Pole. Similarly, there is no such time as "before the Big Bang."
Of course, one can still ask why a universe popped into existence this way. Cosmologists believe the answer lies with the weird properties of quantum mechanics, a topic beyond the scope of this essay.
We can now see that Augustine was right, and popular religion wrong, to envisage God as a superbeing dwelling within the stream of time prior to the creation. Professional theologians acknowledge this. The doctrine of creation ex nihilo (out of nothing) does not mean God pushing a metaphysical button and making a Big Bang, then sitting back to watch the action. It means God sustaining the existence of the universe, and its laws, at all times, from a location outside of space and time.
Can science give any credibility to such a notion? Mostly, scientists either are atheists or keep God in a separate mental compartment. However, there is a strong parallel in the scientific concept of the laws of nature. Like the theologians' God, these laws enjoy an abstract, timeless existence and are capable of bringing the universe into being from nothing. But where do they come from? And why do these laws exist rather than some different set?
Science is based on the assumption that the universe is thoroughly rational and logical at all levels. Miracles are not allowed. This implies that there should be reasons for the particular laws of nature that regulate the physical universe. Atheists claim that the laws exist reasonlessly and that the universe is ultimately absurd. As a scientist, I find this hard to accept. There must be an unchanging rational ground in which the logical, orderly nature of the universe is rooted. Is this rational ground like the timeless God of Augustine? Perhaps it is. But in any case, the law-like basis of the universe seems a more fruitful place for a dialogue between science and theology than focusing on the origin of the universe and the discredited notion of what happened before the Big Bang.