British radio astronomer who carried out pioneering surveys of the radio sky in the 1950s and 1960s. Ryle was awarded the 1974 Nobel Prize for Physics (the first astronomer to be so honoured). He was knighted in 1966 and appointed Astronomer Royal (1972–82).
The son of a physician, Ryle was educated at Oxford University and spent World War II at the Telecommunications Research Establishment in Malvern, working on the development of radar and related projects. In 1945 he joined the staff of the Cavendish Laboratory, Cambridge, as a lecturer in physics. With interest growing in radio astronomy, Ryle used mostly war-surplus equipment to build a radio telescope to investigate the radio sky. His first survey, begun in 1950, noted some fifty radio sources. However, his third survey, dating from 1959, lists the positions and strengths of nearly five hundred sources. Although it has been supplemented by more penetrating surveys it still remains the standard catalogue for the most easily detected sources in the northern hemisphere. The surveys were carried out on an 180-acre site outside Cambridge that, in 1957, became the Mullard Radio Observatory with Ryle as director. Two years later Ryle became Cambridge's first professor of radio astronomy.
The Cambridge surveys played an important role in the cosmological debates of the period. Ryle was one of the first to realize that the distribution of radio sources throughout the universe favoured the big-bang theory as opposed to steady-state cosmology.
Subjects: Astronomy and Astrophysics.