In 1940, he was hired by the Department of Terrestrial Magnetism of the Carnegie Foundation, where he worked with Dr. Scott Forbush under contract for the U.S. Navy to develop ship degaussing techniques during World War II.

In 1948, he earned his Ph.D. in physics with a theory of nucleosynthesis called neutron capture, and from 1948 onward collaborated with Dr. Robert C. Herman, also at APL, on predictions of the cosmic microwave background radiation.

While attending GWU, Alpher met Louise Ellen Simons, who was majoring in psychology at night school and working as a day secretary with the State Department.

As the universe continued to expand and cool, additional nuclear particles would bind with these light nuclei, building up heavier elements such as helium, etc.

Alpher argued that the Big Bang would create hydrogen, helium and heavier elements in the correct proportions to explain their abundance in the early universe.

Alpher and Gamow's theory originally proposed that all atomic nuclei are produced by the successive capture of neutrons, one mass unit at a time.

It was eventually recognized that most of the heavy elements observed in the present universe are the result of stellar nucleosynthesis in stars, a theory largely developed by Hans Bethe, William Fowler and Subrahmanyan Chandrasekhar.

[1] However, Alpher's predictions concerning the cosmic background radiation were more or less forgotten until they were rediscovered by Robert Dicke and Yakov Zel'dovich in the early 1960s.

Gamow joked that "There was, however, a rumor that later, when the alpha, beta, gamma theory went temporarily on the rocks, Bethe seriously considered changing his name to Zacharias".

With the award of the 2005 National Medal of Science, Alpher's original work on nucleosynthesis and the cosmic microwave background radiation prediction was recognised.

Two Nobel Prizes in physics have been awarded for empirical work related to the cosmic background radiation — in 1978 to Arno Penzias and Robert Wilson and in 2006 to John Mather and George Smoot.

[2] Alpher and Herman (the latter, posthumously) published their own account of their work in cosmology in 2001, Genesis of the Big Bang (Oxford University Press).

The citation for the award reads "For his unprecedented work in the areas of nucleosynthesis, for the prediction that universe expansion leaves behind background radiation, and for providing the model for the Big Bang theory."

The medal was presented to his son, Dr. Victor S. Alpher, on July 27, 2007 by President George W. Bush, as his father could not travel to receive the award.

In 1955, both Alpher and Herman applied for positions at Iowa, where van Allen was now department chair, however, the salaries in academia were simply too low by comparison with industrial pay.

Alpher also continued to collaborate with Robert Herman, who had moved to the General Motors Research Laboratory, on problems in cosmology.