Ralph Alpher

Ralph Alpher was an American physicist whose work with George Gamow and Robert Herman developed the theory of primordial element formation and predicted the universe’s relic radiation.

Big Bang nucleosynthesis: The formation of light atomic nuclei during the universe’s first minutes. Alpher’s 1948 calculations with Gamow described how early-universe nuclear reactions could produce light elements.
Neutron capture: A nuclear reaction in which an atomic nucleus absorbs a neutron. Alpher’s early nucleosynthesis model built heavier nuclei by successive neutron captures.
George Gamow: A theoretical physicist who promoted the hot Big Bang and worked with Alpher on primordial nucleosynthesis. Gamow recruited Alpher and helped shape the research program they pursued together.
George Washington University: A private research university in Washington, D.C., founded in 1821. Alpher studied physics there and completed his doctoral work under Gamow.
Cosmic microwave background: Relic electromagnetic radiation from the hot early universe, now observed as a nearly uniform microwave glow. Alpher and Herman predicted this radiation’s present temperature, decades before its detection.
Primordial nucleosynthesis: The production of light nuclei in the hot, dense universe during its first several minutes. This is the physical process Alpher sought to explain quantitatively.
Robert Herman: An American physicist who collaborated with Alpher on predicting the universe’s relic radiation. Herman and Alpher estimated the radiation’s surviving temperature as the universe expanded.
Manhattan Project: The United States-led wartime program that developed the first nuclear weapons. Alpher worked on wartime nuclear research before turning to cosmological nuclear processes.
Alpher–Bethe–Gamow paper: A 1948 paper by Alpher, Bethe, and Gamow proposing that elements formed through neutron capture in the early universe. The paper made Alpher’s nucleosynthesis calculations widely known and gave rise to the famous pun in its author list.
Cosmic expansion: The increase over time of distances between unbound regions of the universe. Expansion cooled the early universe and limited the time available for nuclear reactions in Alpher’s model.

Linked from 8 pages