The Big Bang versus the Steady State: Gamow, Hoyle and Ryle, rivals in cosmology

Abstract This account of the controversy concerning the Big Bang and Steady State theories contrasts the different approaches to science of George Gamow, Fred Hoyle and Martin Ryle. Einstein’s general relativity offered theoretical physicists an indispensable tool kit for making mathematical models of the Universe. Georges Lemaître made an astonishing impact in 1927 with his proposal that the expanding Universe started from a decaying super-radioactive primeval atom. Gamow refined Lemaître’s model by proposing that primordial nucleosynthesis in the early expanding Universe had formed the chemical elements. Hoyle, who by contrast had discovered the conditions under which stellar nucleosynthesis could occur via the evolution and explosion of massive stars, publicly dismissed Gamow’s cosmology as an unnecessary speculation. Hoyle, Hermann Bondi and Thomas Gold proposed the alternative steady state theory in 1948. In 1950 Ryle constructed the first radio telescope with the sensitivity to discriminate between the rival models of the Universe. Steady state cosmology survived Ryle’s first surveys of cosmic radio sources because Ryle’s data was inadequate. However results from the much improved Third and Fourth Cambridge Surveys demonstrated that our Universe had evolved. The Ryle-Hoyle debates became intensely passionate and personal. In 1965 the discovery of the cosmic microwave background radiation settled the argument in favour of the Lemaître Big Bang evolving Universe.