Georges Lemaître and the Big Bang theory

The Big Bang, the Catholic priest who proposed it, and why science and faith aren’t enemies

The Big Bang theory stands as one of the most significant scientific breakthroughs of the 20th century. It describes how the universe began not in a static state, but in a singular, explosive expansion roughly 13.8 billion years ago. What’s less known, but just as remarkable, is that the scientist who first proposed the idea was not only an accomplished physicist, but also a Catholic priest: Georges Lemaître. His work didn’t just revolutionize cosmology - it also challenged the false idea that science and faith must be at odds. In fact, Lemaître’s life and legacy offer a compelling case that scientific inquiry and religious belief can coexist, and that the two can even enrich each other.

The theory that changed everything

Before the Big Bang theory gained traction, many scientists believed in a “steady state” universe; essentially, one that had no beginning and no end. It was static, eternal, and unchanging. This view was comfortable and clean: a cosmos that simply was, without the messy implications of a starting point.

But in 1927, Georges Lemaître, then a relatively unknown Belgian priest and physicist, proposed something radically different. Drawing on Einstein’s general theory of relativity and recent astronomical data, Lemaître suggested that the universe is expanding and that it must have originated from a single, incredibly dense point. He called it the “primeval atom,” what we now call the Big Bang.

His idea was initially met with skepticism, including from Einstein himself. But Lemaître was undeterred. He wasn’t pushing a religious agenda; he was following the evidence. When Edwin Hubble's observations in 1929 confirmed that galaxies are indeed moving away from each other, Lemaître’s theory gained weight. Over time, it became the cornerstone of modern cosmology.

A priest in a lab coat

Georges Lemaître wasn’t a fringe figure trying to inject theology into science. He earned a Ph.D. in physics from MIT, was a member of the Pontifical Academy of Sciences, and held academic positions in both religious and scientific institutions. He moved fluently between the pulpit and the lab, not as a divided man, but as someone who believed truth could be pursued through both scripture and science.

Importantly, Lemaître made a conscious effort to keep his science and his theology in separate lanes. He opposed efforts to use the Big Bang as a proof for the existence of God. When Pope Pius XII once hinted at such an interpretation, Lemaître advised caution. He believed that conflating scientific theories with religious doctrine was a mistake - that science should stand on empirical evidence, not theological endorsement.



This is what made him extraordinary: he didn’t need science to justify his faith, nor faith to legitimize his science. Each had its place, and both were paths to understanding the universe.

Faith and science: False enemies

There’s a popular narrative that science and religion are locked in a centuries-long battle. It’s a story that sells, but it’s not accurate. Sure, history has its share of conflicts: Galileo’s trial, Darwin’s reception, etc. However, these are the exceptions, not rules. The deeper story is more complex and more hopeful.

Science asks "how." Faith asks "why." Science explores mechanisms; faith seeks meaning. The friction comes when one tries to do the other’s job. Problems arise when religion tries to make testable claims about the physical world, or when science declares philosophical or metaphysical truths about purpose or morality.

But at their best, science and faith can complement each other. Science gives us tools to understand the universe; faith gives us reasons to care about it. Science can split the atom; faith can question whether we should. The two can form a fuller picture of reality; one of not competing, but of collaborating.

Lemaître embodied this. His faith didn’t hinder his scientific work; it inspired it. He saw the study of the cosmos as a way to glorify creation;not to prove doctrine, but to understand the vast, unfolding story of the universe.

Why this still matters

In an age of polarization and mistrust, the false war between science and faith is a battle no one wins. When people are told they must choose between being rational and being spiritual, many disengage from one or both. That’s not progress. It’s paralysis.

Lemaître’s legacy pushes back. He reminds us that truth doesn’t come in compartments. The same mind that can question the mysteries of dark matter can also ponder the meaning of love, justice, or existence. Science and faith don’t have to be separate continents. They're more like two lenses - each sharpening the view, each incomplete without the other.



Conclusion

The Big Bang theory didn’t just change how we think about the universe’s origin. It also challenged how we think about the relationship between science and faith. Georges Lemaître, the Catholic priest who launched one of modern science’s greatest revolutions, embodied the truth that one does not need to pick a side. His life and work demonstrate that the pursuit of scientific truth and the commitment to spiritual belief cannot only coexist - they can, indeed, drive each other forward. The universe is vast, mysterious, and still unfolding. There's room in it for both microscope and prayer; for formula and faith.