I was very pleased to see Matt Warner’s post on the fact that the Big Bang theory of cosmology was proposed by the Belgian priest, Fr. Georges Lemaitre (pictured).

This is a really cool thing, and not many people know it. It’s also a terrific way to show people that the Catholic Church isn’t anti-science. “Why, the father of Big Bang cosmology was a Catholic priest!”

Pope Pius XII was also very enthusiastic about the Big Bang (though he didn’t use the term) and its potential to show the coherence of the idea that the universe was created in time, which was widely denied by scientists previously. He gave a speech about this to the Pontifical Academy of the Sciences back in 1951.

Being an astronomy and apologetics buff, I find all of this absolutely jazzy.

But I’d also give a quick word of caution, because Catholics need to be a little careful using the Big Bang in apologetics.

One temptation is to identify the Big Bang not just as the moment of creation but specifically as the creation of light in Genesis 1. That’s problematic because Genesis does not portray the creation of light as the moment the world came into existence. It really doesn’t! Let’s look at the text:

1 In the beginning God created the heavens and the earth.
2 The earth was formless and void, and darkness was over the surface of the deep, and the Spirit of God was moving over the surface of the waters.
3 Then God said, “Let there be light”; and there was light.

The earth already exists in a formless and empty state, with a deep of waters that has a surface, which the Spirit of God hovers over. Then light gets created.

So Genesis depicts the creation of light happening when the heavens and the earth and its waters already existed. At least that is how the text depicts it. You can argue that this isn’t to be taken literally, but that only makes the same point another way: We shouldn’t be too quick to identify the Big Bang with the creation of light in Genesis. We have to be careful about mapping Genesis onto modern cosmology.

But there is another thing we need to be careful about, which is identifying the Big Bang as the moment of creation.

It may well have been! I would love for us to find a way to prove that scientifically.

But we’re not there yet. Scientifically, there is still a lot about the Big Bang that is a mystery. We just don’t understand it. The evidence shows that it happened, but not why it happened. We have very little clue about that scientifically—and there may well be no scientific answer. It may be that God just did it, and did it in a way not susceptible to scientific study.

But that’s not the only option. There are others that cannot presently be ruled out on scientific grounds. For example, the visible universe we see today may have budded off of a larger universe that we cannot see, and the moment it budded off may have been the Big Bang. There are other options, too.

If one of those options is the case, it just means that God created the universe—from nothing—even farther back in time than we can currently see.

But new scientific instruments may allow us to go even further back. In fact, there are plans for a new set of scientific projects that may let us discern something about the state of the universe before the Big Bang (if there was one).

In his 1951 speech, while hailing the Big Bang, Pius XII also cautioned that “the facts established up to the present time are not an absolute proof of creation in time, as are the proofs drawn from metaphysics and revelation.”

So, while the idea of the Big Bang is consistent with the idea that the universe was created a finite time ago, and while the Big Bang may be that moment of creation, we need to be a little careful on that score.