| Activity | Education:
Bradfield College Berkshire; Christ Church Oxford, gained first class honours in physics (1939)
Career:
Lecturer in Physics (1948); Director of the MRAO (1957-1982); Professor of Radio Astronomy (1959-1982); Astronomer Royal (1972), first to hold tyhe post after it was separated from the office of Director of the Royal Observatory. President of Commission 40 (Radio Astronomy) of the International Astronomical Union (1964-1967).
Recruited by his examiner at Oxford, J A Ratcliffe, to join the ionospher research group at the Cavendish Laboratory in Cambridge. Followed Ratcliffe into the scientific war effort, later joining the Telecommunications Research Establishment (TRE) to work on the problem of air defence, later being given the leadership of one of the groups working on radio counter-measures and deception. Returned to the CAvendish Laboratory in 1945, Ryle shifted his research interest to a new phenomenon that had come to his attention through a secret war-time report, suggesting that some jamming of anti-aircraft radar wa potentially associated with radio emissions from the sun. In his investigations of the sun as a radio emitter, Ryle came up with a solution to a difficulty posed by the equipment then available. Together with D D Vonberg, he adapted tradar equipment, using two aerials that could be moved apart, and connecting them to the same receiver by cable. In effect Ryle created a radio anaogue of the Michelson interferometer, and with the forerunner of a series of increasingly sophisticated radio interferometers with which he and his Cambridge colleagues would make their surveys of the distribution of radio sources coming from the sky. By 1957 these instruments required the relocation of the radio observtory to a site outside the centre of Cambridge at Lord's Bridge. This was named the Mullard Radio Astronomy Observatory (MRAO) in acknowledgement of a grant from the electronics company Mullard Ltd. Her esucceeding generations of instruments were built which used the 'aperture synthesis' technique. By 1972 they included the One-Mile Tlescope and the Five-Kilometre Telescope, whose eight parabolic reflefctors arranged along a five-kilometre baseline became a familiar landmark in the creation of a succesion fo Cambridge Catalogues of Radio Souorce, with Ryle principallty involved inthe Second (2C), published in 1955, and the Third (C3), published in 1959.
Following the early work on sunspots, Ryle and his research team moved progressibely towards the 'radiostars' outside the solar system. by the mid 1950s their number counts revealed a large excess of faint sources, suggenting that there had been many mor esources inthe distant past. In a paper published by the Royal Society in July 1955, Rykle and P A G Scheuer presented an interpretation of these findings that flew in the face of the steady state theory, according to which the universe had the same overall appearance at all cosmic episodes. There ensued controversy, both with proponents of the steady state theory, in particular Cambridge astronomer Fred Hoyle, and with radio astronomers in Sydney, whose surveys of the southern sky did not bear out the Cambridge results. Subsequent analysis fo the Cambridge survey and the discovery in 1965 of cosmic microwave background radiation by A A Penzias and R W Wilson substantiated the claim of an evloveing universe. In 1974 Ryle and his Cambridge colleague Antony Hewish were jointly awarded the Nobel prize for physics'. The citation explicitly described the development of aperture synthesis as Ryle's major contribution.
With the advent of the oil crisis in the early 1970s Ryle became increasingly preoccupied with the problem of long-term energy supply, emerging as both a public critic of nuclear power and a passionate advocate of alternative evergy sources. The latter pursuit involved him in a research and development programme to construct against nuclear weapons, supporting the Campaign for Nuclear Disarmament and allied organisations, and to speak out on a range of current affairs issues.
Medals and prizes:
Nobel Prize (Physics) 1974
Memberships:
Foreign Member of the Soviet Academy of Sciences (1871) and the Deutsche Akademie der Naturforscher Leopoldina (1974; Foreign Associateship of the National Academy of Sciences, USA (1975); Gold Medal of he Royal Astronomical Society (1964); the Holweck Prize of the Societe Francaise de Physique (1965); the Popov Medal of the Soviet Academy of Sciences (1971).
Honours:
Kt 1966 |