Physics and Cosmology

This article considers the role of physics in transforming cosmology into a research field which relies heavily on fundamental physical knowledge. It begins with an overview of astrophysics and the state of physical cosmology prior to the introduction of relativity, followed by a discussion of Albert Einstein’s application of his new theory of gravitation to cosmology. It then examines the development of a theory about the possibility of an expanding universe, citing the work of such scientists as Edwin Hubble, Alexander Friedmann, Georges Lemaître, and George Gamow; the emergence of the field of nuclear archaeology to account for the origins of the early universe; and the controversy sparked by the steady-state theory. It also describes the discovery of a cosmic microwave background of the kind that Alpher and Herman had predicted in 1948 before concluding with a review of modern cosmological hypotheses such as the idea of ‘multiverse’.