George Lemaître Is The Forgotten Astronomer — And Priest — Behind The Big Bang Theor

The only non-controversial thing to say about the combination of science and religion is that it's controversial. But if you look at Georges Lemaître, you can see that the two don't have to be sworn enemies. Never heard of him? Many people haven't, but a certain guy named Albert Einstein was a big fan.

Georges Lemaître, born in Charleroi, Belgium in 1894, was a busy man in the early 20th century. After he was awarded a Belgian War Cross as an army officer in World War I, he earned degrees in math and philosophy at the Catholic University of Leuven. Soon after that, he was ordained as a priest. Ever the scientist, he was given permission to study at prestigious Harvard Observatory while, at the same time, earning his Ph.D in physics from MIT. How's that for a résumé?

In 1927, Lemaître cooked up the revolutionary theory that still impacts how we view our universe today. His article entitled "A Homogeneous Universe of Constant Mass and Increasing Radius accounting for the Radial Velocity of Extra Galactic Nebulae" stated that the universe is expanding. After this groundbreaking paper was published, Lemaître realized he may have missed something. If the universe is always expanding, when and how did all that begin? Boom, baby — literally. He planted the seeds for the Big Bang Theory in a May 9, 1931 letter to Nature.

The idea he hatched in that letter would late make its way into a collection of essays written by Lemaître. In it, he calls the beginning of the universe "now without yesterday," more popularly known as "the day without yesterday." After a few more scientists pitched in to beef up the idea, it became the Big Bang Theory.

At this point, you're probably scratching your head wondering how this guy's name isn't common knowledge. The only explanation is that there was simply a rain cloud hovering over Lemaître's head. Sheer bad luck. Let us explain...

That groundbreaking 1927 paper that stated the universe is continuously expanding? Though it was undoubtedly Nobel Prize-worthy, astronomy was not yet considered a part of physics, which made this astronomer's work ineligible for the award.

Okay, so he didn't win the Nobel. But maybe he at least got some credit? Nah, you can find that in Edwin Hubble's name. Though Lemaître did all the math, Hubble got the credit for providing the observational basis for the things Lemaître crunched numbers on. The things we owe to Lemaître include what's now known as Hubble's Law and Hubble's Constant, as well as the idea that the universe is expanding.

Surely the Big Bang thing was a big deal at the time, right? Yes and no; it was met with a lot of criticism because, well, science and religion tend to butt heads. The scientific community was hesitant to go with an origin story that came from a priest. In 1952, Pope Pious XII proclaimed Lemaître's work was proof of a creator. Lemaître didn't agree with this interpretation, arguing with the Pope to pipe it down. But perhaps it was too little, too late for the scientific community of the time.

At least Einstein knew there was something to this guy. After Lemaître described his theories in January 1933 at the California Institute of Technology in Pasadena, Einstein declared, "This is the most beautiful and satisfactory explanation of creation to which I ever listened."