Big Bang nucleosynthesis is the process by which the light elements, chiefly hydrogen, helium and small amounts of lithium, were formed from protons and neutrons during the first few minutes after the Big Bang, while the universe was still hot and dense enough to fuse nuclei. The predicted abundances of these primordial elements, especially the roughly 25 percent helium fraction by mass, closely match what is observed in the oldest, least processed matter in the universe, making the theory one of the strongest pieces of evidence for the Big Bang model. Nearly all heavier elements were produced later, inside stars and in stellar explosions, rather than during this early period.
Facts
Concept Domain Formulated YearThe Alpher-Bethe-Gamow paper formalizing the theory was published in 1948, following Gamow early-1940s realization that explosive cosmic expansion could drive the needed nuclear reactions. Proposed ByGeorge Gamow and Ralph Alpher 1 Connections
Sources
1. Wikipedia (space and spaceflight articles)
Wikimedia FoundationWikipedia, Big Bang nucleosynthesis, History sectionQuote, Wikipedia, Big Bang nucleosynthesis, History section
Early in the 1940s Gamow realized that very high temperatures and pressures needed for nuclear reactions implied an explosion followed by expansion. Calculations by his student Ralph Alpher, published in the famous Alpher-Bethe-Gamow paper, outlined an early theory of light-element production in the early universe.
Big Bang nucleosynthesis (Wikipedia)
Wikipedia, Big Bang nucleosynthesis, lead paragraph
In physical cosmology, Big Bang nucleosynthesis (also known as primordial nucleosynthesis, and abbreviated as BBN) is a model for the production of light nuclei (including, but not limited to, 2H, 3He, 4He, and 7Li) during the first ~20 minutes of the evolution of the universe.
In Group: Big Bang Cosmology and Measurements, Lead sentence
In physical cosmology, Big Bang nucleosynthesis (also known as primordial nucleosynthesis, and abbreviated as BBN) is a model for the production of light nuclei (including, but not limited to, 2H, 3He, 4He, and 7Li) during the first ~20 minutes of the evolution of the universe.
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