The Belgian cleric and professor of physics Abbé Georges Lemaître (1894–1966) was a remarkable contributor to the development of the theory of the expanding universe, in the heady years following two great revolutions in fundamental physics: Einstein's general theory of relativity, and quantum mechanics. Not until the 21st century was the impact of his 1927 paper on the expansion of the universe fully recognised. My most highly cited paper on Lemaître (217 KB) was published in 2017, to mark the fiftieth anniversary of his death. In it I recount how Lemaître arrived at his theory of a Fireworks Universe that commenced with a Big Bang.

The expanding universe of Georges Lemaître, by Simon Mitton. Astronomy and Geophysics, vol. 58 (April 2012), 2.28–2.31.


Here is a general level presentation about Georges Lemaître the great pioneer who discovered the expansion of the universe in 1927. Lemaître was the greatest cosmologist of them all in the 1930s. Today he is recognised as "Father of the Big Bang" by the International Astronomical Union. His influence is addressed in my book Heart of Darkness - Unraveling the Mysteries of the Invisible Universe

Georges Lemaître: Life, Science and Legacy Presentation given at an Ordinary Meeting of the Royal Astronomical Society on 11 November 2016

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Simon Mitton gives an exciting presentation for amateur astronomy societies on the Fireworks Universe of Georges Lemaître, and the early history of exploding models of the universe. Other cosmologists featuring in this talk are Alexander Friedman, Vesto Slipher, Edwin Hubble, Arthur Eddington, Fred Hoyle, Tommy Gold, Hermann Bondi, and Allan Sandage. The final part of the talk shows how dark matter and dark energy feature in modern concordance cosmology. This topic is also addressed in my book published by Princeton University Press, Heart of Darkness - Unraveling the Mysteries of the Invisible Universe

Georges Lemaitre: The Fireworks Universe

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Here is a short presentation titled Cambridge Scientific Minds. Includes William Gilbert, William Harvey, Isaac Newton, Arthur Eddington, and Fred Hoyle. It is used as an introduction to a tour of the Whipple Museum of the History of Science

Cambridge Scientific Minds

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Here is something completely different, an interesting enquiry of the impact of the cosmology of Bishop Robert Grosseteste (1175-1253), also Plato, Aristotle, Hipparchus of Niceae, Ptolemy of Alexandria, and Nicolaus Copernicus. Scholars are elevating Grosseteste as a major natural philosopher in the thirteenth century. Bishop Grosseteste University in Lincoln, UK is named after him.

Geometry and cosmology in Antiquity and the Middle Ages

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Read here (doc, 54 KB)


Simon Mitton's presentation at the Hay-on-Wye Festival in 2011 which was a sell-out. Hay Festival 2011

The books are Ptolemy's Almagest (140 AD), Copernicus' De Revolutionibus (1543), Galileo's Sidereus Nuncius - the Starry Message (1610) and Dialogo (1636), and Newton's Principia Mathematica (1687). These are the great books that moved the study of the heavens from capricious Greek gods and their myths to the truth of mathematics and physics.

Five Books that changed our view of the universe

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Here's Simon Mitton's presentation on Fred Hoyle given in 2011. It's a lively account of a lively life! Hoyle was an extremely accomplished nuclear astrophysicist who established that we are all made of stardust.

Fred Hoyle A life in science: 1915 - 2001

View here (pdf, 12.2 MB)