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Father of the Big Bang at St Edmund’s

Ninety years ago this year, the priest and scientist Georges Lemaître (St Edmund’s 1923-24) proposed the theory of the ‘Expanding Universe’ – several years before Edwin Hubble popularised the theory as ‘Hubble’s Law’. Extrapolating from the idea he developed a further hypothesis, heavily criticised by the likes of Albert Einstein and mockingly called ‘Big Bang Theory’.

Lemaître at Eddies

Ten days after his ordination to priesthood in 1923, Lemaître arrived in Cambridge. He joined the residential community of young Catholic priests at St Edmund’s House, paying £100 in advance for 32 weeks of full board and lodging. He had won a substantial cash prize for a dissertation on general relativity, which funded his studies here. His companions included eight English priests preparing for teaching positions in Catholic schools, as well as four Jesuits from Missouri and New York. Intellectually he embarked on a demanding programme of study, including general relativity in association with Professor Arthur Eddington. Eddington later wrote in a reference: “I found M. Lemaître a brilliant student … of great mathematical ability. ... I hope he will do well at Harvard.”

Lemaître and the expanding universe

Lemaître spent his next two years at Harvard and MIT. By the time he returned to his old university at Louvain, he had a firm grasp of Edwin Hubble’s research on measuring the distances of remote galaxies, and Vesto Slipher’s work on measuring their velocities. He became the first scientist to propose the theory of an expanding universe, abandoning Einstein’s concept of a static universe entirely. He published this result in French in the summer of 1927. It was overlooked by other researchers, until Eddington arranged to have an English translation published. Einstein initially rejected the theory, calling Lemaître’s physics ‘atrocious’, not conceding until 1935, calling the theory ‘beautiful’.

Following this theory Lemaître proposed the ‘hypothesis of the primeval atom’ or the ‘Cosmic Egg’ exploding at the moment of creation. Lemaître believed the universe had always existed, in an extremely compact state, from which it suddenly exploded billions of years ago, as a ‘Fireworks Universe’. The idea, that one quantum could be the origin of all matter in the universe and that the expansion was accelerating, was mocked by colleagues, calling it the ‘Big Bang Theory’.

After the detection of fossil radiation from the ‘Big Bang’, in 1965, Lemaître’s reputation as a great scientist was confirmed.

Earlier Life

Georges Lemaître came from a devout Catholic family. He completed his secondary education in Brussels at Collège St-Michel, after which he enrolled at the Louvain. Here he studied engineering and philosophy, as well as taking an interest in the history of mathematics: he read Euclid in Greek, and worked through the Latin texts of Euler, Gauss and Jacobi. When he graduated with distinctions in mathematics and physics, he was having second thoughts about becoming an engineer: spiritually he was attracted to the priesthood.

He enlisted in the Belgian army at the outbreak of WWI, and spent four years on the Western Front, seeing very little action until late 1918. In his little free time he mastered physics at an advanced level and engaged with Einstein’s general theory of relativity. On return to Louvain in 1919, he continued to work on the implications of Einstein’s mathematical toolkit for studying the properties of the entire universe. He came to St Edmund’s directly after his ordination to priesthood and began his studies in Cambridge in Michaelmas 1923.

Lemaître’s rediscovery at Eddies

Life Fellow Simon Mitton (elected 1974), can be credited with reestablishing St Edmund’s link with its famous priest-scientist. ‘I came to Cambridge in 1968,’ Simon writes, ‘as a doctoral student working for Sir Martin Ryle on radio galaxies. I was prompted to leave nuclear physics at Oxford and move to Cambridge as the discovery of the cosmic microwave background, faint radiation from every part of the sky, a fossil relic of the fiery birth of our universe, had been made here recently. It was also the year that Jocelyn Bell at New Hall discovered pulsars out at Barton.’

Two competing models were in the air at the time: the Big Bang and the steady state models of the universe. Cambridge had passionate advocates for each: Ryle in the Cavendish Laboratory for the Big Bang, and the mathematician Fred Hoyle for a steady state. They argued furiously for about 15 years, but by 1968 Hoyle had lost the battle. Simon came to know the factions on both sides, ‘but I never heard anyone mention Lemaître. In fact, I had been a Fellow for 30 years when a colleague casually told me he must have lived at St Edmund’s House. None of us had thought of that!’ Since then, Simon has worked tirelessly to ensure our priest-scientist is remembered at Eddies.


Lemaître, although highly decorated by both the Roman Catholic Church and the world of science, was a humble man and not bitter that Hubble’s name became attached to his theory. In a small way, Lemaître stands for our College motto ‘by revelation and reason’, showing that science and religion are compatible.

The European Space Agemcy named an ATV-5 after him. Watch the video on YouTube

Today, the Reverend Monsignor Georges Lemaître is remembered at St Edmund’s with a prize in his name and a commemorative plaque in the Chapel.

Watch College Fellow Dr Rodney Holder's University of Cambridge lecture 'Georges Lemaître vs Fred Hoyle: Contrasting Characters in Science and Religion' on YouTube.