After World War II he began to establish Cambridge as a centre for radio astronomy, opting for radio interferometers rather than parabolic receivers. With A. Hewish he developed the technique of aperture synthesis and commenced a series of surveys of radio sources that were published as the Cambridge catalogues, the best known of which is the Third Cambridge Catalogue (objects in it are preceded by the designation 3C). The large number of faint radio sources discovered helped discredit the steady-state theory. Ryle shared the 1974 Nobel Prize in Physics for his work on aperture synthesis.