The following is a guest post by Dr. Elizabeth Fernandez, who is both a friend and colleague of Dr. Salviander. Dr. Fernandez is a Catholic, an astrophysicist, and a freelance journalist. She is interested how science affects society, interfaith dialog, and the overlap of science with ethics, philosophy, and religion. Dr. Fernandez’s participation in interfaith dialog has included radio and television appearances, and organizing panel discussions, lectures, and field trips. You can follow her on Twitter at @sparkdialog.

Is it possible to be devoted to religion, yet come up with cutting edge science? Georges Lemaître thought so.

Lemaître. Probably the greatest scientist you’ve never heard of. He hung out with the likes of Hoyle, Eddington, and Einstein. And he came up with one of the most controversial ideas of modern cosmology, an idea that fundamentally changed how we looked at the universe.

Oh, yeah. And he was a Catholic priest.

Georges Lemaître always had two passions in life: science and religion. He knew he wanted to be a priest when he was 10 years old. While he served in WWI with the Belgian army, he read the Bible alongside physics textbooks while huddled in the trenches. He earned two bachelor’s degrees — one in math, and one in philosophy. He attended graduate school at the same time he was in the seminary, and is one of those rare, very dedicated people who earned not one but two PhDs — one in math and one in physics. He was one of the first people to suggest that computers could be used to solve complex problems, and was one of the inventors of the Fast Fourier Transform, an often-used tool in mathematics and computing.

At the time Lemaître started his research, around the beginning of the 1920s, the preferred view of the universe was Albert Einstein’s static universe. In this universe, galaxies hang in a fixed constellation with respect to one another, unmoving through the eons. Of course, physics tells us that gravity should draw all of these galaxies towards one another, and, if you wait long enough, everything would come together in a catastrophic collapse. In order to keep this from occurring, Einstein added a “cosmological constant” to counteract gravity: some mysterious outward force that would exactly balance the inward pull of gravity. This universe has no beginning; in fact, it’s ageless — quite possibly always existing in the same configuration we see today.

But Lemaître had a different idea. Since 1912, another astronomer named Vesto Slipher noticed in his observations that many galaxies were receding from Earth quite quickly. This didn’t quite fit into the concept of a static universe. Some scientists thought this was just a fluke, and others thought of it as one of the great cosmological puzzles of the time. It was Lemaître who figured it out. After delving into relativity, he came up with a new model of the universe – a model where space itself was expanding. This expanding space had the ability to whisk galaxies along with it, which explained the recessional velocities measured by Slipher. It was revolutionary. According to Lemaître’s model, the universe could change.

A changing universe… it was an incredible idea, but most scientists didn’t pay much attention. Einstein, even though he respected Lemaître greatly, didn’t believe his hypothesis, saying to Lemaître, Vos calculs sont corrects, mais votre physique est abominable. (“Your calculations are correct, but your physics is abominable.”) Lemaître’s own PhD advisor, Arthur Eddington, left Lemaître’s paper sitting on his desk, either unread or forgotten.

But Lemaître did not stop there. Three years later, he proposed an even more radical idea. He extrapolated the motions of the expanding galaxies backwards, predicting that at some time in the far distant past, all matter was compressed to one single point, what Lemaître called the “primeval atom.” Not only was the universe evolving, but it had a beginning.

Just as when Copernicus proposed that the earth went around the sun rather than the other way around, Lemaître’s idea was not met with accolades. Eddington didn’t like the idea of the primeval atom. Einstein thought it was unphysical. Lemaître’s own friend, astrophysicist Fred Hoyle, was a big opponent of the theory, explaining its shortcomings on public radio.

But, contrary to what most physicists of the day believed, Lemaître ended up being right. A couple of years after Lemaître made his prediction about the expansion of the universe, Edwin Hubble observationally confirmed Slipher’s discovery that galaxies are in fact moving away from one another. (Hubble is commonly credited for discovering the expanding universe because of these observations, even though Lemaître made his prediction years earlier. Oddly enough, when Hubble first observed these galaxies moving away from Earth, he vehemently stated these motions had nothing to do with an expanding universe, but rather should somehow fit into the static universe model.) And shortly before Lemaître died, he heard the final confirmation of his primeval atom hypothesis when astrophysicists, Arno Penzias and Robert Woodrow Wilson, announced their discovery of the cosmic microwave background — the leftover radiation from the fireball of the universe’s creation. Now, Lemaître’s theory is so well known that it’s a household name — the big bang theory.

I wonder what many people would think if they knew one of the most well known scientific theories of our day was developed by a Catholic priest. Today, there is considerable debate if science and religion are compatible. Lemaître faced some of this controversy, but it did not distract him. To put it simply, he was in search for the truth: a truth that could be accessed through science, but also through religion. In the words of Lemaître:

Man’s highest activity is searching for the truth. It is the factor which distinguishes us from animals, and our specific activity is to grasp the truth in all its forms.

Once you realize that the Bible does not purport to be a textbook of science, the old controversy between religion and science vanishes . . . The doctrine of the Trinity is much more abstruse than anything in relativity or quantum mechanics; but, being necessary for salvation, the doctrine is stated in the Bible. If the theory of relativity had also been necessary for salvation, it would have been revealed to Saint Paul or to Moses . . . As a matter of fact neither Saint Paul nor Moses had the slightest idea of relativity.

The universe is an amazing, complex place. Georges Lemaître, in his quest for the truth, saw past the prevailing theories of the day to discover something fascinating and beautiful, a universe with a beginning, with galaxies constantly in motion, a universe that is, in the words of Lemaître, the “ashes and smoke of bright but very rapid fireworks”.