Big bang nucleosynthesis what happened in the first few minutes after the big bang usually astronomers work on time scales of thousands to billions of years for objects in the sky to develop and change.
Big bang nucleosynthesis gamow, alpher and herman proposed the hot big bang as a means to produce all of the elements however, the lack of stable nuclei with atomic weights of 5 or 8 limited the big bang to producing hydrogen and helium. 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.
I will then discuss the consequences of the big bang b nucleosynthesis on modern physics: the cosmology”, and the review article “big bang nucleosynthesis and physics beyond the temperature of the kind of particle studied.
This reaction is exothermic with an energy difference of 22 mev, but since photons are a billion times more numerous than protons, the reaction does not proceed until the temperature of the universe falls to 1 billion k or kt = 01 mev, about 100 seconds after the big bang. Big bang nucleosynthesis predicts a primordial abundance of about 25% helium-4 by mass, irrespective of the initial conditions of the universe. For a movie of big bang nucleosynthesis, click here for more info roughly three minutes after big bang, temperature of universe rapidly cooled from its phenomenal 10 32 kelvin to approximately 10 9 kelvin, allowing nucleosynthesis, or the production of light elements, to occur.
Big bang nucleosynthesis main article: big bang nucleosynthesis big bang nucleosynthesis  occurred within the first three minutes of the beginning of the universe and is responsible for much of the abundance of 1 h ( protium ), 2 h (d, deuterium ), 3 he ( helium-3 ), and 4 he ( helium-4 . Theory of big bang nucleosynthesis the relative abundances of the lightest elements (hydrogen, deuterium, helium-3 and helium-4, and some lithium and beryllium) provide a strong test of the hypothesis that the. Roughly three minutes after the big bang itself, the temperature of the universe rapidly cooled from its phenomenal 10^32 kelvin to approximately 10^9 kelvin at this temperature, nucleosynthesis, or the production of light elements, could take place.
The conditions during big bang nucleosynthesis were just perfect to create about 25% helium, 75% hydrogen, and much less than 1% of everything else but don't just take our word for it, lets prove it. Had the results been in conflict, it would point to 1) errors in the data, 2) an incomplete understanding of the process of big bang nucleosynthesis, 3) a misunderstanding of the mechanisms that produce fluctuations in the microwave background radiation, or 4) a more fundamental problem with the big bang theory.