Alpher-Bethe-Gamow theory
The Alpher-Bethe-Gamow theory ("αβγ theory") is the first theory of element formation in the early universe . It was published in 1948 by Ralph Alpher and George Gamow . The supervisor Gamow of the then PhD student Alpher took the liberty of joking and named the name of the actually uninvolved Hans Bethe as a co-author based on the Greek alphabet .
The theory describes the formation of the elements from a hot proton and neutron gas, which Alpher called Ylem ( ancient Greek ὑλῆ - hylê) (the term Ylem was already used by Aristotle to denote the primordial matter from which everything was created) . Due to the expansion of the universe, the density and temperature of this mixture of particles drop so far that the nucleons can unite to form stable atomic nuclei . The Alpher-Bethe-Gamow theory therefore forms the basis of today's theory of primordial nucleosynthesis .
While Alpher and Gamow postulated the origin of all elements from the Big Bang , we now know that only nuclei of the heavy isotopes of hydrogen ( deuterium and tritium ), as well as helium and traces of lithium and beryllium, could have formed in the early universe; all heavier elements were later created in stars and supernovae . The relative frequencies of the hydrogen and helium isotopes have already been correctly predicted by Alpher and Gamow.
literature
- Alpher, RA, Bethe, H., Gamow, G .: "The Origin of Chemical Elements", Physical Review 73, 803 (1948); doi : 10.1103 / PhysRev.73.803 .