RAS Public Lecture: Gravitational lensing, or how to detect and me asure the warps of space-time

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Gravitational lensing, or how to detect and measure the warps of space-time
Prof David Valls-Gabaud
(Venue: Geological Society Lecture Theatre- no booking required) Gravitational lensing is an ubiquitous phenomenon which allows astronomers to detect exoplanets, dark matter in galaxies, weigh clusters of galaxies, and even constrain the topology of the universe. Contrary to a widespread -but wrong- consensus, Newton was not the first scientist to ponder on this effect, which is produced by the distortion of space-time, and is best described by Einstein's general relativity. This talk will review the surprising evolution in the concept of gravitational lensing over two centuries. Professor David Valls-Gabaud is Director of Research at CNRS and works at the Observatoire de Paris. Elected Overseas Fellow of Churchill College, University of Cambridge, in 2015, he was educated at the universities of Madrid, Paris and Cambridge. He has hold research positions in Toronto, Cambridge, Hawaii and Beijing, as well as visiting positions at the European Southern Observatory. He was also awarded a Senior International Professorship by the Chinese Academy of Sciences. His fields of expertise range from the cosmic microwave background to stellar populations through galaxy evolution and gravitational lensing. While his research activities are mostly focused on theoretical and modelling issues, he currently leads the MESSIER satellite project to map the low surface brightness sky at optical and UV wavelengths. A member of professional astronomical societies in France, UK, Spain, and USA, he is currently the secretary of commission C3 (History of Astronomy) of the International Astronomical Union, and vice-president of the Societe Astronomique de France (funded in 1887).