George Gamow

Major contributions

• Showed in 1928 that alpha decay occurs by quantum tunnelling of the alpha particle through the potential barrier of the nucleus, explaining the enormous range of half-lives observed (see Alpha Decay and Quantum Tunnelling); Ronald Gurney and Edward Condon reached the same explanation independently
• Introduced the Gamow factor, the tunnelling probability that also governs nuclear fusion rates in stars, leading to the Gamow peak and window used in stellar astrophysics (see Nuclear Fusion)
• Proposed with Ralph Alpher that light elements were synthesised in the hot early universe (the 1948 “alpha–beta–gamma” paper), a cornerstone of the Big Bang theory
• With Edward Teller, formulated selection rules for beta decay (Gamow–Teller transitions, 1936), and studied late stellar evolution including red giants
• In 1954 proposed that groups of three nucleotides encode amino acids, an early information-theoretic approach to the genetic code; his specific “diamond code” was wrong but the triplet idea proved correct

Named concepts

Career

Gamow was born in Odessa and studied at the University of Leningrad, where he worked with Alexander Friedmann before the latter's death in 1925. He spent time in Göttingen, Copenhagen (with Niels Bohr, see Niels Bohr) and Cambridge in the late 1920s and early 1930s. In 1933, after attending the Solvay Conference in Brussels, he did not return to the Soviet Union; he emigrated to the United States in 1934 and became a professor at George Washington University, where he remained until 1956 and then moved to the University of Colorado Boulder.

His 1948 work with his doctoral student Ralph Alpher proposed that neutron capture in the hot early universe built up the elements; the paper appeared in Physical Review on 1 April 1948 with Hans Bethe's name added as a middle author, a joke on the Greek letters alpha, beta and gamma. The mechanism did not work beyond helium and lithium, as there are no stable nuclei with mass number 5 or 8, and heavier elements are now known to form in stars (see Stellar Nucleosynthesis). However, Alpher and Robert Herman showed in the same year that the model implied a relic radiation, then estimated at about 5 K, anticipating the cosmic microwave background.

Key publications

• Gamow, G. (1928). “Zur Quantentheorie des Atomkernes.” Zeitschrift für Physik, 51, 204–212.
• Alpher, R.A., Bethe, H., Gamow, G. (1948). “The Origin of Chemical Elements.” Physical Review, 73, 803–804.
• Gamow, G. (1970). My World Line: An Informal Autobiography. Viking Press.

Nobel Prize

George Gamow never received a Nobel Prize. The 1978 Nobel Prize in Physics for the discovery of the cosmic microwave background went to Arno Penzias and Robert Wilson (with Pyotr Kapitsa for separate work), by which time Gamow had died (1968; the prize is not awarded posthumously). Ralph Alpher and Robert Herman, who made the background-radiation prediction, were not honoured by the prize, a frequently noted omission in the history of cosmology.

Historical context

Gamow's hot Big Bang picture competed with the steady-state theory of Hoyle, Bondi and Gold until the 1965 discovery of the background radiation (see Big Bang Theory). The name “big bang” was coined by Fred Hoyle in a 1949 BBC radio talk describing the rival theory. The credit for the radiation prediction was slow to reach Alpher and Herman, and Penzias and Wilson's discovery paper did not cite their work, a point that historians of science continue to discuss. Gamow is also the source of the well-known story that Einstein called the cosmological constant his “biggest blunder”; the account appears in his 1970 autobiography and is secondhand (see Cosmological Constant). His popular books, such as One Two Three... Infinity (1947), introduced many readers to modern physics; he received UNESCO's Kalinga Prize for popularisation of science in 1956.