Who Is Georges Lemaître? Big Bang Theory Physicist and Priest Honored by Google Doodle

Georges Henri Joseph Édouard Lemaître was a priest, physicist and astronomer whose controversial "cosmic egg" theory became the most prominent concept in cosmology—the Big Bang theory.

Now, on the scientist's 124th birthday, Google has honored him with a Doodle. But who is Georges Lemaître and what were his most important ideas?

Today's #GoogleDoodle celebrates Georges Lemaître, a Belgian astronomer and professor of physics who proposed what became known as the Big Bang theory. 🌌 → https://t.co/QMsS5eQEWV pic.twitter.com/JbfUPHJf5f

— Google UK (@GoogleUK) July 17, 2018

Lemaître was born in Charleroi, Belgium, in 1894. His original career as a civil engineer was interrupted by World War I and the future astrophysicist ended up serving in the Belgian army. When the war ended, Lemaître switched to math and physics, before joining the Catholic priesthood in 1923.

He went on to become a professor of astrophysics at the Catholic University of Leuven in Belgium. In 1927 he published a French-language article that proposed the universe was expanding. Building on Albert Einstein's theory of general relativity, the work made little impact on the field until it was translated into English in 1931. An abbreviated version appeared in the Monthly Notices of the Royal Astronomical Society.

This idea of an expanding universe led the physicist towards the concept of a "cosmic egg" that exploded in the first moment of the universe. Also known as the "Primeval atom," Lemaître thought this single point expanded into the incomprehensibly vast universe of today.

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An artist's impression of the Big Bang. Getty Images

Although he faced derision from some, the priest's ideas were becoming more mainstream. Other scientists had also grown skeptical of the idea the universe was static.

American astronomer Edwin Hubble was also investigating the notion of an expanding universe around the same time as Lemaître. In 1929, Hubble went one step further and found observational evidence that the universe was expanding.

Scientists including George Gamow built on Lemaître's ideas. What began as a "cosmic egg" hatched into what is still the most prominent theory of cosmology—the Big Bang theory. The observation of cosmic background radiation bolstered the notion even further in 1965.

Lemaître died in Leuven, Belgium, in 1966 at the age of 71. During his lifetime he won several awards recognizing his contributions to science, including the inaugural Eddington Award bestowed by the Royal Astronomical Society.

Outside of astronomy, his love of algebra and arithmetics fuelled a passion for computer science which was growing toward the end of his life.

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Lemaître also devoted himself to his Catholic faith, which he considered a separate lens through which to view the universe.

According to the Neil DeGrasse-Tyson-edited book Cosmic Horizons: Astronomy at the Cutting Edge, the priest once said: "As far as I can see, such a theory remains entirely outside any metaphysical or religious question. It leaves the materialist free to deny any transcendental Being… For the believer, it removes any attempt at familiarity with God… It is consonant with Isaiah speaking of the hidden God, hidden even in the beginning of the universe."