Dennis Sciama | |
|---|---|
 | |
| Born | Dennis William Siahou Sciama (1926-11-18)18 November 1926 Manchester,Lancashire, England |
| Died | 18 December 1999 (aged 73) Oxford, England |
| Alma mater | Trinity College, Cambridge[6] |
| Known for | Rees–Sciama effect |
| Spouse | |
| Children | 2 |
| Awards |
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| Scientific career | |
| Fields | Gravitation |
| Institutions | |
| Thesis | On the origin of inertia (1952) |
| Doctoral advisor | Paul Dirac[2] |
| Doctoral students | |
Dennis William Siahou Sciama,FRS (/ʃiˈæmə/; 18 November 1926 – 18 December 1999)[7][8] was an Englishphysicist who, through his own work and that of his students, played a major role in developing British physics after the Second World War.[9][10] He was the PhD supervisor to many famous physicists and astrophysicists, includingJohn D. Barrow,David Deutsch,George F. R. Ellis,Stephen Hawking,Adrian Melott andMartin Rees, among others; he is considered one of the fathers of moderncosmology.[11][12][13][14]
Sciama was born inManchester,England, the son of Nelly Ades and Abraham Sciama.[15] He was ofSyrian-Jewish ancestry — his father born inManchester and his mother born in Egypt, but both traced their roots back toAleppo,Syria.[16]
Sciama earned his PhD in 1953 at theUniversity of Cambridge supervised byPaul Dirac,[2] with a dissertation onMach's principle andinertia. His work later influenced the formulation of scalar-tensor theories of gravity.
Sciama taught atCornell University,King's College London,Harvard University and theUniversity of Texas at Austin, but spent most of hiscareer at theUniversity of Cambridge (1950s and 1960s) and theUniversity of Oxford as a SeniorResearch Fellow inAll Souls College, Oxford (1970s and early 1980s). In 1983, he moved from Oxford toTrieste, becoming Professor of Astrophysics at theInternational School for Advanced Studies (SISSA), and a consultant with theInternational Centre for Theoretical Physics. He also taught at theScuola Normale Superiore ofPisa.
From 1972 to 1973 he was theDonegall Lecturer in Mathematics atTrinity College Dublin.[17]
During the 1990s, he divided his time between Trieste (with a residence in nearbyVenice) and his main residence atOxford, where he was a visiting professor until the end of his life.
Sciama made connections among some topics inastronomy andastrophysics. He wrote onradio astronomy,X-ray astronomy,quasars, the anisotropies of thecosmic microwave radiation, the interstellar and intergalactic medium, astroparticle physics and the nature ofdark matter. Most significant was his work ingeneral relativity, with and withoutquantum theory, andblack holes.[18] He helped revitalize the classical relativistic extension to general relativity known asEinstein-Cartan gravity.
Early in his career, he supportedFred Hoyle'ssteady state cosmology, and interacted with Hoyle,Hermann Bondi, andThomas Gold. When evidence against the steady state theory, e.g., thecosmic microwave radiation, mounted in the 1960s, Sciama abandoned it and worked on theBig Bang cosmology; he was perhaps the only prominent Steady-State supporter to switch sides (Hoyle continued to work on modifications of steady-state for the rest of his life, while Bondi and Gold moved away from cosmology during the 1960s).
During his last years, Sciama became interested in the issue of dark matter ingalaxies. Among other aspects, he pursued a theory of dark matter that consists of a heavy neutrino, certainly disfavored in his realization, but still possible in a more complicated scenario.
Several leadingastrophysicists andcosmologists of the modern era completed their doctorates under Sciama's supervision, notably:
Sciama also strongly influencedRoger Penrose, who dedicated hisThe Road to Reality to Sciama's memory. The 1960s group he led in Cambridge (which included Ellis, Hawking,[20] Rees, and Carter), has proved of lasting influence.
Sciama was elected aFellow of the Royal Society (FRS) in 1983.[7] He was also an honorary member of theAmerican Academy of Arts and Sciences, theAmerican Philosophical Society and the Academia Lincei of Rome. He served as president of the International Society of General Relativity and Gravitation, 1980–84.
His work at SISSA and the University of Oxford led to the creation of a lecture series in his honour, theDennis Sciama Memorial Lectures.[21] In 2009, the Institute of Cosmology and Gravitation at theUniversity of Portsmouth elected to name their new building, and their supercomputer in 2011, in his honour.[22]
Sciama has been portrayed in a number of biographical projects about his most famous student, Stephen Hawking. In the 2004 BBC TV movieHawking, Sciama was played byJohn Sessions. In the 2014 filmThe Theory of Everything, Sciama was played byDavid Thewlis; physicistAdrian Melott strongly criticized the portrayal of Sciama in the film.[23]
Sciama was of Jewish-Syrian descent and an avowed atheist.[24] In 1959, Sciama married Lidia Dina, a social anthropologist, who survived him, along with their two daughters.[7]
