The Priest Who Discovered the Beginning
In 1927, a Belgian Catholic priest named Georges Lemaître published a paper that would change humanity’s understanding of the universe. Working with Einstein’s equations of general relativity, Lemaître proposed that the universe is expanding — that the galaxies are moving apart from each other, and that if you trace their motion backward in time, everything converges to a single point. He called this point the “primeval atom” — the seed from which the entire universe grew.
Two years later, Edwin Hubble confirmed observationally what Lemaître had derived mathematically: the galaxies are indeed receding from each other. The universe is expanding. And if it is expanding now, it must have been smaller in the past — all the way back to a beginning.
The theory eventually became known as the Big Bang — a name coined, somewhat mockingly, by the astronomer Fred Hoyle, who preferred the rival “steady state” model in which the universe had no beginning. But the evidence accumulated relentlessly in favour of Lemaître’s proposal: the cosmic microwave background radiation (discovered in 1965), the abundance of light elements, and the large-scale structure of the universe all pointed to a hot, dense beginning approximately 13.8 billion years ago.
The man who saw it first was a priest.
The Church’s Response
The Church’s response to the Big Bang has been consistently positive — and this surprises people who assume the Church is hostile to science.
Pope Pius XII, in a 1951 address to the Pontifical Academy of Sciences, welcomed the Big Bang as evidence compatible with the existence of a Creator. He noted that modern science had confirmed what Genesis taught: the universe had a beginning.
Lemaître himself was uncomfortable with the Pope’s enthusiasm — not because he disagreed with the theology, but because he believed science and theology should not be confused. He wrote to the Pope urging caution: the Big Bang, he said, is a scientific theory, not a proof of God. It is compatible with creation, but it should not be used as a theological argument in a way that ties the faith to a scientific model that might one day be revised.
This distinction — between compatibility and proof — is precisely right, and it reflects the mature Catholic understanding of the relationship between faith and science. The Big Bang does not prove God exists. But it is entirely consistent with the Catholic belief that the universe was created — and its implications point strongly in a theistic direction.
What the Big Bang Implies
The Big Bang tells us something extraordinary: the universe had a beginning. Time, space, matter, and energy all came into existence at a single moment, approximately 13.8 billion years ago. Before that moment, there was no “before” — because time itself began at the Big Bang.
This has profound philosophical implications.
Something cannot come from nothing. This is one of the oldest and most fundamental philosophical principles — ex nihilo nihil fit. If there was nothing before the Big Bang — no matter, no energy, no space, no time — then the universe did not cause itself. Something outside the universe — outside space, outside time, outside matter — must have brought it into existence.
The cause must be immaterial and eternal. Whatever caused the universe cannot itself be material (since matter began at the Big Bang) or temporal (since time began at the Big Bang). It must be something that exists beyond the physical universe — something immaterial and timeless.
The cause must be intelligent and personal. The universe did not emerge from a physical process, because there was no physical process before the Big Bang. The cause must have acted freely — choosing to create, rather than being compelled by prior physical conditions. A free choice implies an agent — a mind, a will, a person.
This description — an immaterial, eternal, intelligent, personal cause of the universe — is remarkably close to what Catholics mean by God.
What Lemaître Understood
Lemaître was careful to keep his science and his theology distinct. He did not claim that the Big Bang proved God. He said: “As far as I can see, such a theory remains entirely outside any metaphysical or religious question.”
But he also saw no conflict between his faith and his physics. He attended Mass daily. He said the breviary. He served as president of the Pontifical Academy of Sciences. He saw no tension between studying the origins of the universe and believing that the universe had a Creator — because he understood that the two kinds of knowledge operate at different levels.
Science tells you how the universe began — the physics, the mathematics, the observational evidence. Faith tells you why — the purpose, the meaning, the Person behind the process. Lemaître studied the how with the rigour of a world-class physicist. He believed the why with the faith of a devoted priest. And he saw both as aspects of one truth.
“There is no conflict between science and religion,” he said. “There is only conflict between bad science and bad religion.”
The Steady State Alternative
Not everyone was happy with the Big Bang. Some scientists — notably Fred Hoyle — preferred the steady state model, in which the universe has no beginning and no end. New matter is continuously created to fill the expanding space, and the universe looks the same at all times.
The motivation was partly scientific and partly philosophical. Hoyle was an atheist, and he was uncomfortable with the implications of a beginning. A universe with a beginning sounds uncomfortably like a universe that was created. The steady state model avoided this implication by positing a universe that has always existed.
But the evidence went against the steady state. The discovery of the cosmic microwave background in 1965 — the faint afterglow of the Big Bang, detectable in every direction — was the decisive blow. The steady state model could not explain it. The Big Bang could. By the 1970s, the scientific community had largely abandoned the steady state in favour of the Big Bang.
The irony is rich: a Catholic priest proposed a theory with theistic implications. An atheist proposed the alternative. The evidence sided with the priest.
What the Church Teaches
The Church does not require you to believe in the Big Bang. It is a scientific theory, subject to revision as new evidence emerges. The Church’s teaching on creation is theological, not scientific: God created the universe from nothing (creatio ex nihilo), freely, deliberately, and with purpose. How He did it — whether through a Big Bang, through some other process, through mechanisms not yet discovered — is a question the Church leaves to science.
But the Church does teach that the universe had a beginning — that it is not eternal, that it came into existence through the will of God. This is a truth of faith, revealed in the first verse of Scripture: “In the beginning God created the heavens and the earth.” The Big Bang is consistent with this truth. It does not prove it. But it resonates with it in a way that makes the Catholic, standing at the intersection of faith and science, feel very much at home.
The First Word and the Last
Lemaître died on 20 June 1966, two days after learning that the cosmic microwave background had been detected — the final confirmation of his theory. He knew, before he died, that the universe had a beginning.
He also knew — as a priest, as a man of faith, as a daily communicant — that the beginning had a Beginner. That the first moment of the universe was not a random fluctuation in a void but the first word of a love story — a story that began with light and is still being told.
“In the beginning God created the heavens and the earth.” Science has confirmed the beginning. Faith names the Creator. And a Catholic priest — standing at the intersection of both — saw further than anyone else.