The universe is a puzzle. And it keeps surprising us.

When I was an astronomy student in the 1980s, we knew our best estimate of the age of the universe was wrong. It came out younger than some of stars we could see – very embarrassing! But the puzzle started long before then.

In the early 20^th century, leading scientists – including Albert Einstein – were convinced the universe had existed forever. Many were uncomfortable with time having a beginning. But Edwin Hubble’s discovery that the universe is expanding forced them to see otherwise: by measuring the expansion rate we could work backwards and predict when the expansion (and the universe itself) started.

The big bang model

The early universe must have been extremely hot and dense, and this period, when all the lighter elements were formed, became known as “the big bang.” In fact, the originator of the idea, physicist and Jesuit priest Georges Lemaitre called it the theory of the primeval atom.

Our measurements of those early elements and our detection of the radiation they emitted all match the big bang predictions. We even got the age right eventually. The universe had a beginning about 13 billion years ago.

The big bang theory has been an incredibly successful scientific hypothesis; it has been confirmed in various ways and it fits the data that we have. But the big bang needed some extra stuff to explain how it would result in the universe we see today, which is so uniform. Some rather crazy stuff is needed … really crazy. The best explanation is that the universe expanded incredibly just before the first elements of matter formed. We call this period of sudden expansion “inflation.”

I have been privileged to play a small part in investigating these things. As a Christian, the science helps me appreciate the wonderful universe God has made. It is a universe more amazing than humans could ever have imagined – as the surprises along the way to the big bang model demonstrate. Human wisdom was reluctant to accept a start to the universe, but the evidence showed otherwise.

The beginning of time?

In a recent article, physicist Chanda Prescod-Weinstein points out that we used to think of the big bang as the very beginning of the universe. However, she explains that “big bang” is a term better used to describe the specific period when the elements were formed, after the inflationary period.

The idea of an early inflationary period before matter was formed solves some big scientific problems, but it also reveals more puzzles. For example, what started the inflation? And, more importantly, what stopped it?

Further work has resulted in some mathematical models where the universe is continually undergoing inflation with no beginning at any time in the past. The models do allow the inflation to stop in specific regions or “bubbles.” If this is right, then we live in one of those bubbles where inflation stopped, and the material elements formed. Yes, our bubble still had a big bang period, which created the matter of stars and planets. However, as Professor Prescod-Weinstein explains, this eternal inflation model no longer needs a beginning to time.

For scientists, this eternal inflation model is more comfortable because it avoids the mathematical problem of a “singularity” when time begins at the big bang. With this “eternal inflation” understanding of the history of the universe, we are back to where we were before Hubble discovered our expanding universe.

What do I think of all this as a person of faith?

First, the universe continues to surprise us in how wild a place it is. It is just so beyond anything that humans could ever imagine. For me, creation appears more and more beautiful. For me, faith and science are different parts to the same discovery of creation.

I could speculate about how the Christian creation story relates to this scientific model of an eternal universe, but that would be rather presumptuous. I used to suggest that the big bang theory represented a convergence between scientific thought and the Christian creation story just because it also had a beginning. However, that may now have changed; perhaps we are wrong to try and seek exact convergences between science and the Bible, which, after all, was not written as a scientific textbook.

As experts, such as scientist and theologian Alister McGrath, have pointed out, aiming to match your beliefs up with specific scientific results is unwise because the science keeps changing.

Yes, the universe is a puzzle and it keeps surprising us.

Professor Michael Drinkwater’s research interests are in astronomy, specialising in cosmology and galaxy formation. He completed his PhD at The University of Cambridge in 1988. He has since worked at Laval University in Québec, the Anglo-Australian Observatory, the University of New South Wales, the University of Melbourne and the University of Queensland. He is an associate of ISCAST–Christians in Science and Technology.