From hikers lying on their backs in a field looking up at a star-studded sky to scientists with PhDs in astrophysics looking through sophisticated telescopes, people seek to answer the burning question, “How did this all begin?”

The “Big Bang Theory” is popular, because most everyone loves something that begins with an “explosive moment.”

But there is indeed science behind this theory, and it was introduced by a Belgian Catholic priest

Father Georges Lemaître was also an astronomer and cosmologist who studied Albert Einstein’s theory of relativity and observed some of the conditions of the early cosmos in the 1920s to 30s. He theorized that the redshift of galaxies could be caused by the expansion of the universe and there must have been an initial moment of creation at the beginning.

Through decades it was known as either the “primeval atom” or the “cosmic egg.”  According to Father Lemaître,  around 13.7 billion years ago, all matter in the universe was concentrated into a single, infinitesimally tiny point. He theorized the universe began to expand rapidly through a hot and huge explosion and is still expanding today. The Big Bang Theory was also believed as the reason why space and time were created.

Although the idea was guided by Einstein’s theory of relativity, he dismissed Father Lemaître’s work in 1927. He was impressed with Father Lemaître’s findings but was not swayed, saying “Vos calculs sont corrects, mais votre physique est abominable,” which in English means, “your calculations are correct, but your physics is abominable!”

Father Lemaître’s initial discovery has become what was eventually known as Hubble’s law. Many scientists before Einstein theorized the cosmos was made up entirely of the Milky Way galaxy. But in the 1920s Edwin Hubble refuted it as he observed nebulae that were too distant to be part of our galaxy and were in fact, galaxies of their own.

Hubble further proved that other galaxies are moving away from our galaxy at a speed directly proportionate to their distance from us – making the “Hubble’s Law.” This was consistent with the idea of the “Big Bang Theory” that if the universe is currently expanding, then it was smaller, denser and more uniform in the past.

After meeting at several conferences, Father Lemaître and Einstein talked about their points of agreement in their theories and eventually became friends.

Another piece of evidence that supports “The Big Bang Theory” is the existence of cosmic background radiation – the oldest radiation in our universe. This is not only contained in all matter but also all the energy in the universe.

And when the universe expanded, the high energy electromagnetic radiation cooled down and stretched over time. This cosmic background radiation gives a peek into the early universe when electrons and protons were combining to form hydrogen atoms.

But Father Lemaître argued that his theory was not meant to explain the beginnings of the universe in a theological sense but from a physical one.

“But (the Christian researcher) knows that not one thing in all creation has been done without God, but he knows also that God nowhere takes the place of his creatures. Omnipresent divine activity is everywhere, essentially hidden. It never had to be a question of reducing the supreme being to the rank of a scientific hypothesis,” Father Lemaître said.

The Catholic Church embraced Father Lemaître’s theory as proof that the birth of the universe was the work of God, the creator and mover of all. In the early 1950s, when the Big Bang Theory gained prominence in the scientific community, Pope Pius XII publicly favored the theory and stated: “It would seem that present-day science, with one sweep back across the centuries, has succeeded in bearing witness to the august instant of the primordial Fiat Lux (Let there be light), when along with matter, there burst forth from nothing a sea of light and radiation, and the elements split and churned and formed into millions of galaxies. Thus, with that concreteness which is characteristic of physical proofs, science has confirmed the contingency of the universe and also the well-founded deduction as to the epoch when the world came forth from the hands of the creator. Hence, creation took place. We say ‘Therefore, there is a creator. Therefore, God exists!’ ”