Today’s Google Doodle celebrates the 124th birthday of the man who was the first to theorise that the universe is constantly expanding. In 1927, Georges Lemaitre — a lecturer at Catholic University of Leuven — propounded the precursor to the Big Bang theory in his published paper titled “A homogenous Universe of constant mass and growing radius accounting for the radial velocity of extragalactic nebulae.”

Lemaitre’s thesis was based on, and borrowed from Einstein’s Theory of General Relativity but when he shared his ideas with the latter, Einstein was least impressed. The German –born theoretical physicist is known to have reported back saying, “Your calculations are correct, but your physics is atrocious.”

Soon enough, however, Lemaitre’s theory was backed up by Edwin Hubble’s observations. In fact, Lemaitre had, in his paper, successfully calculated the numerical value that describes the rate of expansion of universe, what we now refer to as the Hubble constant.

Born on 17 July, 1894 in Belgium, Lemaitre served as a Belgian artillery officer during World War I. He later went on to study physics and obtained a doctorate for the same in 1920. Next, he began studying astronomy and surprisingly, was ordained a Catholic priest. His role as a priest and a scientist rarely intersected. In 1951, Pope Pius XII publically announced that the Big Bang theory offered scientific proof of Christian religious belief regarding the origin of life, to which Lemaitre responded negatively. For Lemaitre, science and religion were two mutually exclusive arenas that did not enjoy the privilege of coexistence.

Lemaitre is known to be a student at University of Cambridge, Harvard and Massachusetts Institute of Technology (MIT). In 1934, he was honoured with the highest scientific accolade of Belgium—the Francqui prize. He was also awarded with the Eddington Medal, in 1953, by the Royal Astronomical Society for investigations of outstanding merit in theoretical astrophysics.

Today, Google celebrates the extraordinary life of Georges Lemaitre by creating a doodle of him in the midst of an ever-expanding mass of galaxies and light, just as he first theorised.