The discovery that the universe started with a "big bang" out of an unimaginably small, hot and dense structure was a fascinating discovery.
It suggested that the universe had a beginning. But why did it happen? Christians point to God as the ultimate cause of the universe and in his sermon on the feast of the Epiphany, Pope Benedict reminded us of this.
Recent discussion on this topic followed the publishing of books about a physical theory that explains why the big bang happened.
For a long time, physicists had argued that questions about the cause of the big bang are meaningless as the big bang is also the origin of time, so there can be nothing before it. Others argued that the universe's expansion would eventually end and turn into a contraction, and what we call the big bang is just one of an eternal cycle of universes forming and collapsing again.
The most recent physical theories emerge out of attempts to explain all the forces of nature in one unified way, a "theory of everything." In this theory, our universe is just one of many universes that emerge somewhat like bubbles in boiling water.
The cosmos in which these universes form is seen as timeless or eternal and defined by nothing more than the laws of physics. Our universe has a beginning and an end, but the universe-creating cosmos simply exists.
This is a fascinating theory. The mathematics behind it is far too difficult for me to understand, so I am in no position to judge its validity. My interest is how this relates to the understanding of reality beyond what we can observe and measure. Is this theory the answer to the question why there is something rather than nothing?
We are creatures of this universe and it is fundamentally impossible for us to make any observations of universes other than our own. If they existed, we could never know them.
Mathematical theories explaining the origin of the universe are therefore metaphysics, not physics. They are not about the physical world, but about why there is a physical world. And I readily admit: if string theory becomes a theory of everything that can also explain the big bang, it would be a tremendous success for the human intellect. I hope they got it right.
However, my faith in God the Father, the creator of heaven and earth, remains entirely unshaken. Should I believe that the ultimate cause of everything is eternally existing laws of physics, or that it is the triune God - Father, Son and Holy Spirit? If the physical world is fully explained by the laws of physics, were there really nothing left to explain?
Rather than thinking about the big bang, it is the experience of being a human person that should be the starting point of our metaphysics. As persons in relationship with other persons, knowing and (I hope) loving each other, we are able to grasp that the meaning of our lives goes beyond what is known as physics.
The nature of this "beyond" must come out of the knowledge of love and what it means to be a person. This points to the relationships between the divine persons of the Trinity as the true reason why we exist and why there is a cosmos with laws of physics for us to discover.
(This article was originally published on Brother Joachim's online blog where he writes about science and religion: brotherjoachim.blogspot.com.)