In physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than H-1, the normal, light hydrogen, during the early phases of the universe, shortly after the Big Bang.

It is believed to be responsible for the formation of hydrogen (H-1 or simply H), its isotope deuterium (H-2 or D), the helium isotopes He-3 and He-4, and the lithium isotope Li-7.

Big Bang nucleosynthesis begins about one minute after the Big Bang, when the universe has cooled enough to form stable protons and neutrons, after baryogenesis.

From simple thermodynamical arguments, one can calculate the fraction of protons and neutrons based on the temperature at this point.

This fraction is in favour of protons, because the higher mass of the neutron results in a spontaneous decay of neutrons to protons with a half-life of about 15 minutes..

For more information about the topic Big Bang nucleosynthesis, read the full article at Wikipedia.org, or see the following related articles:

Shape of the Universe — The shape of the Universe is a subject of investigation within physical cosmology. Cosmologists and astronomers describe the geometry of the Universe ...  > read more

Nucleosynthesis — Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). The primordial preexisting nucleons ...  > read more

Galaxy formation and evolution — The formation of galaxies is still one of the most active research areas in astrophysics; and, to some extent, this is also true for galaxy ...  > read more

Physical cosmology — Physical cosmology, as a branch of astrophysics, is the study of the large-scale structure of the universe and is concerned with fundamental ...  > read more

Related Stories

Big Bang Theory Saved (October 27, 2006) — An apparent discrepancy in the Big Bang theory of the universe's evolution has been reconciled by astrophysicists examining the movement of gases in stars. Professor John Lattanzio from Monash's ...  > read more

Dilaton Could Affect Abundance Of Dark Matter Particles (October 2, 2007) — The amount of dark matter left over from the early universe may be less than previously believed. The 'relic abundance' of stable dark matter particles such as the neutralino may be reduced as ...  > read more

Did 'Dark Matter' Create The First Stars? (March 20, 2006) — Dark matter may have played a major role in creating stars at the very beginnings of the universe. If that is the case, however, the dark matter must consist of particles called "sterile neutrinos". ...  > read more

Scientists Crack Open Stellar Evolution (October 31, 2006) — Using 3-D models run on some of the fastest computers in the world, laboratory physicists have created a mathematical code that cracks a mystery surrounding stellar ...  > read more

Scientists Find Faint Objects With Hubble That May Have Ended The Universe's 'Dark Ages' (January 10, 2003) — Researchers using NASA's Hubble Space Telescope reported they are seeing the conclusion of the cosmic epoch called the "Dark Ages," a time about a billion years after the big bang when ...  > read more

Search ScienceDaily

First Stars In The Universe