Alpher, Ralph Asher (1921–2007)

US physicist and cosmologist, he carried out the first quantitative work on nucleosynthesis and in 1948 was the first to predict the existence of primordial background radiation, which is now regarded as one of the major pieces of evidence for the validity of the Big Bang model of the universe.

Alpher was born in Washington, DC, and educated there as a night-school student. Later he carried out research at Johns Hopkins University and, 1955–86, at the Central Electric Research Laboratory. He was a professor of physics and astronomy at Union College, Schenectady, New York, 1987–2004.

In 1948 Alpher and cosmologist George Gamow published the results of their work on nucleosynthesis in the early universe. They included the name of physicist Hans Bethe as a co-author of this paper, so that their new theory became popularly known as the alpha-beta-gamma theory.