Science and the Cosmological Argument for God’s Existence

One common argument for the existence of God, developed by Medieval Muslim philosophers, is known as the Kalam Cosmological Argument. In its basic form, it runs as follows:

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

The only way to avoid this argument’s conclusion is to claim that the universe is eternal, and so never began to exist. Indeed, many atheists have claimed that it is impossible to prove that the universe began to exist. Even the great Medieval Christian philosopher St. Thomas Aquinas, who developed several philosophical arguments for the existence of God, believed it was impossible to prove that the universe began to exist. 

In the 20th century, however, new scientific evidence was discovered which strongly supported the idea that the universe had a beginning. Astronomers discovered that the universe was expanding at a rapid rate. Extrapolating backwards, this implied that, at some point a finite amount of time ago, the universe began to expand from a singularity. This idea became known as the Big Bang Theory.

Disturbed by the theistic implications of the idea that the universe began to exist, some atheist scientists proposed alternatives to the Big Bang Theory, such as the steady-state theory. However, further scientific discoveries, such as the discovery of cosmic microwave background radiation produced by the big bang, provided confirmation of the Big Bang Theory against its rivals. Thus, by the late 20th century, the Big Bang Theory was nearly universally accepted by scientists. 

In order to avoid the implication of the Big Bang Theory that the universe began to exist, some have hypothesized that the universe is infinitely oscillating between expansion and contraction; the big bang will be followed by a “big crunch,” followed by another big bang, and so on, an infinite number of times. However, this is impossible. First of all, there is no mechanism that has been proposed to explain what would cause the universe to contract and then expand again, over and over. Secondly, this hypothesis is contradicted by the second law of thermodynamics, which states that the entropy (disorder) of an isolated system increases over time. The second law of thermodynamics means that, over time, the oscillations of the universe would get longer and longer, until the universe eventually reached “heat death,” when no energy would be available to do the work of expanding and contracting the universe. If the universe had been oscillating an infinite number of times in the past, then this state of the universe would have been reached an infinite time ago, so the currently observed expansion of the universe could never have happened. 

Another hypothesis that attempts to avoid the implication of the Big Bang Theory that the universe began to exist is the hypothesis of an eternally existing primeval “atom” of matter. According to this hypothesis, the matter of the universe has existed eternally as an extremely dense “atom,” but, about 13.7 billion years ago, a quantum fluctuation caused this matter to expand into the big bang. This hypothesis, however, is also impossible. If the eternally existing primeval “atom” of matter was unstable in this way, then it would have expanded an infinite time ago, not exactly 13.7 billion years ago. On the other hand, if the eternally existing primeval “atom” of matter was eternally stable, then it could never expand, unless a cause from outside the universe caused it to expand.

Physicist and cosmologist Stephen Hawking attempted to find a way to describe the physics of the big bang that would avoid the Big Bang Theory’s implications of a spatiotemporal singularity at the beginning of the universe. When theorizing about the physics of the early, tiny universe, Hawking introduced imaginary time (an imaginary number is a real number multiplied by i, the square root of -1) into one of Einstein’s equations describing spacetime. The result depicted a universe with spatial dimensions but no temporal direction or beginning. In his popular book, A Brief History of Time, Hawking presented this as proving that the universe did not necessarily have a definite beginning in time.^[1]Stephen Hawking, A Brief History of Time: From the Big Bang to Black Holes. New York: Bantam, 1998. The problem with Hawking’s claim is that imaginary numbers are an abstract mathematical construct that cannot exist in the real world. Thus, Hawking’s mathematical formula cannot correspond to the real universe. Hawking himself acknowledged, “When one goes back to the real time in which we live, however, there will still appear to be singularities. . . Only if [we] lived in imaginary time would [we] encounter no singularities. . . In real time, the universe has a beginning and an end at singularities that form the boundaries to space-time and at which the laws of science break down.”^[2]Hawking, 136. While there is nothing wrong with Hawking’s mathematical calculations, the metaphysical implications he attempted to draw from them were faulty. 

Thus, it is clear that the universe does go back to a singularity a finite amount of time ago. The universe began to exist. Some atheists have acknowledged that the universe began to exist, but then have simply claimed that the universe began to exist without a cause; they argue that quantum physics has shown us that something can indeed come from nothing. What they mean by this is that, in the realm of quantum physics, material particles can emerge from preexisting energy-rich fields in a preexisting space. But an energy possessing quantum vacuum that behaves according to the equations of quantum physics is not “nothing”; it is very much something. Absolutely nothing in the science of quantum physics supports the idea that the universe could begin to exist without a cause.

Science cannot prove absolutely that the universe began to exist. However, the findings of modern science strongly support the idea that the universe began to exist. And if the universe began to exist, it must have a cause. And the best explanation for the cause of the universe is an extremely powerful, personal agent: God. As astrophysicist Robert Jarrow put it, “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 mountains 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.”^[3]Jastrow, Robert. God and the Astronomers. New York: Norton, 1992. Page 116.