Georges Henri Joseph Édouard Lemaître RAS Associate was a Jesuit trained Belgian Catholic priest, mathematician, astronomer, and professor of physics at the Catholic University of Louvain.He was the first to identify that the recession of nearby galaxies can be explained by a theory of an expanding universe, which was observationally confirmed soon afterwards by Edwin Hubble. He was the first to derive what is now known as Hubble's law, or the Hubble–Lemaître law, and made the first estimation of what is now called the Hubble constant, which he published in 1927, two years before Hubble's article. Lemaître also proposed what later became known as the "Big Bang theory" of the origin of the universe, initially calling it the "hypothesis of the primeval atom".
