Martin Rees

Martin John Rees was born on June 23, 1942.⁠[1]

He has recalled being born in York and brought up on the Welsh borders as an only child; his parents, both teachers, started a progressive boarding school in south Shropshire in 1948, which he attended until he was 13, after which he was sent to Shrewsbury School.⁠[2]

He read mathematics at Trinity College, Cambridge, and later said he realized he preferred synthetic thinking and seriously considered economics; in 1964 he became a research student, getting into Dennis Sciama’s group because another candidate dropped out, just after quasars had been discovered.⁠[3]

In 1966 he predicted in Nature that an object moving relativistically in suitable directions may appear to a distant observer to move transversely much faster than light; a few years later such superluminal motion was found in radio galaxies and quasars using very long baseline interferometry.⁠[4]

He received his PhD in 1967 and was on the staff of Cambridge’s Institute of Theoretical Astronomy from 1967 to 1972, with spells at Caltech and the Institute for Advanced Study in PrincetonPrinceton UniversityPrinceton University is a private university and Ivy League member in Princeton, New Jersey. Chartered on October 22, 1746 as the College of New Jersey, it moved to Princeton in 1756 and adopted its present name in 1896. Undergraduate education leads to A.B. and B.S.E. degrees and emphasizes small-group discussion, independent research and residential college life. Graduate education spans the humanities, social sciences, natural sciences and engineering. As of October 2026, Christopher L. Eisgruber was president. Its 2026–27 operating budget was $3.407 billion, including $342 million for undergraduate aid.Open the full entry.⁠[1]

He recalled getting to know Fred Hoyle when he received his PhD in 1967; Hoyle offered him a postdoctoral job at his new institute, though Sciama remained the more important scientific mentor.⁠[2]

In 1968 he and Dennis Sciama were the first to predict that fluctuations in the microwave background arise from the uneven distribution of matter in the universe; with Simon White he was also first to identify the central role of dark matter in forming large-scale structure.⁠[5]

After a short period at the University of Sussex he was appointed Plumian Professor of Astronomy at only 31, by which time he had published over 50 papers.⁠[6]

In 1973 he became a fellow of King’s College and Plumian Professor of Astronomy and Experimental Philosophy at Cambridge, holding the chair until 1991, and served for ten years as director of Cambridge’s Institute of Astronomy.⁠[7]

He chaired the European Space Agency’s Scientific Advisory Committee when it decided to collaborate with NASANASAThe National Aeronautics and Space Administration (NASA) is the U.S. federal agency responsible for the civilian space program, aeronautics research and space science. Established by law in 1958 and headquartered in Washington, D.C., it has run programs including Mercury, the Apollo Moon landings, the Space Shuttle, the International Space Station and Artemis.Open the full entry on Ulysses and the Hubble Space Telescope.⁠[8]

In 1992 he became a Royal Society Research Professor and President of the Royal Astronomical Society.⁠[8]

He was knighted in 1992 and appointed to the Order of Merit in 2007.⁠[1]

In 1995 he was appointed the 15th Astronomer Royal.⁠[6]

Gravity’s Fatal Attraction, written with Mitchell Begelman, was published by Freeman in December 1995; Before the Beginning appeared in January 1997; and Just Six Numbers was published in the UK in October 1999.⁠[9]

Just Six Numbers argues that the universe can be characterised by six numbers, including the number of spatial dimensions, the ratio of the strength of gravity to that of electromagnetism and the cosmological constant.⁠[10]

He received the 2001 Gruber Cosmology Prize, whose citation said many of his ideas on radio sources, black holes, galaxy formation and gamma-ray bursts had been vindicated by later observations.⁠[8]

Heinemann published his 228-page Our Final Century in 2003 (in the US as Our Final Hour); the book argues that humankind has no more than a 50-50 chance of surviving another 100 years and discusses new technological risks such as bioterror and self-replicating nanomachines.⁠[11]

Diplomat and environmentalist Crispin Tickell, reviewing it, called the book easy and persuasive reading and a stimulus to thought but questioned the author’s pessimistic odds.⁠[12]

The Cambridge University Reporter of October 1, 2003, announced that the Queen had approved his appointment as Master of Trinity College in succession to Amartya Sen, who would retire on January 14, 2004.⁠[13]

In 2005 he entered the House of Lords, sitting as a crossbencher, and was made Baron Rees later that year.⁠[14]

He was President of the Royal Society from 2005 to 2010, its 60th president.⁠[15]

On January 27, 2005, the Royal Swedish Academy of Sciences announced that the 2005 Crafoord Prize in Astronomy would go to James E. Gunn, P. James E. Peebles and him for contributions towards understanding the large-scale structure of the universe, with the USD 500,000 prize shared equally.⁠[16]

In the Royal Society’s 350th anniversary year he delivered the 2010 BBCBBCThe BBC (British Broadcasting Corporation) is the United Kingdom’s public broadcaster. Its predecessor was the British Broadcasting Company, formed in 1922, and since 1927 it has been established under a Royal Charter. It provides television, radio, and online services in the UK, is funded mainly by the television licence fee, and broadcasts worldwide in multiple languages through BBC World Service.Open the full entry Reith Lectures, titled Scientific Horizons, as its president; the first lecture, The Scientific Citizen, aired on BBC Radio 4 on June 1, 2010, and called on scientists to help the public understand science.⁠[17]

On April 6, 2011, the John Templeton Foundation announced at the Royal Institution in London that he had won the 2011 Templeton Prize, worth £1,000,000; in a statement he said that even in a perspective of billions of years this century may be a defining moment.⁠[18]

In November 2012 the University of Cambridge described the proposed Centre for the Study of Existential Risk, formed through an alliance of philosopher Huw Price, Skype co-founder Jaan Tallinn and Rees, to study technologies such as biotechnology, nanotechnology, extreme climate change and artificial intelligence that might pose extinction-level risks.⁠[19]

On October 16, 2018, Princeton University Press published his 260-page On the Future: Prospects for Humanity; a review said it develops themes of his Reith Lectures and, while addressing risks such as nuclear weapons and climate change, is optimistic about technology overall.⁠[20]

Polity Press published his If Science Is to Save Us in 2022.⁠[21]

The book identifies three interlinked challenges of food and energy, the ethics of biotechnology and artificial intelligence, and argues that scientists should take part in public policy and that experts should be embedded in government at a high level.⁠[22]

On April 19, 2022, Harvard UniversityHarvard UniversityHarvard University is a private research university in Massachusetts, established by the Massachusetts Bay Colony legislature in 1636 and named in 1639 for early benefactor John Harvard. Its principal campuses are in Cambridge and the Allston and Longwood neighborhoods of Boston. It includes Harvard College, graduate and professional schools, and the Radcliffe Institute for Advanced Study. Two governing boards share oversight. Alan M. Garber was president as of October 2026, and the endowment stood at $56.9 billion at the end of fiscal 2025.Open the full entry Press’s Belknap Press published The End of Astronauts, written with science writer Donald Goldsmith, which argues that space exploration beyond low-Earth orbit should proceed with robots rather than astronauts.⁠[23]

He appeared on episode 305 of the Lex FridmanLex FridmanLex Fridman is a Soviet-born, US-raised computer scientist and podcast host who works as an MIT research scientist on human-AI interaction and autonomous driving. His Lex Fridman Podcast is known for hours-long conversations with guests including heads of state and technology leaders.Open the full entry Podcast, whose description calls him a cosmologist and astrophysicist at Cambridge University and co-founder of the Centre for the Study of Existential Risk; topics included dark matter, alien life, space exploration, future technology, Newton and Einstein, black holes and cosmological threats.⁠[24]

As of October 2026 he is a Fellow of Trinity College and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge and holds the honorary title of Astronomer Royal; he has written or co-written more than 500 research papers.⁠[7]

He is married to the anthropologist Caroline Humphrey.⁠[25]

Personal website: Public link: https://www.martinrees.uk/ (opens in a new window)⁠[24]

X: Public account: https://x.com/LordMartinRees (opens in a new window)⁠[15]

University of Cambridge: Official website: https://www.cam.ac.uk/ (opens in a new window)⁠[19]

Royal Society: Official website: https://royalsociety.org/ (opens in a new window)⁠[17]

Centre for the Study of Existential Risk: Official website: https://www.cser.ac.uk/ (opens in a new window)⁠[26]