What were the first few events that happened immediately after the Big Bang?

1 Answer
Nov 18, 2015

It was a very turbulent time.


  • At the big bang itself the universe is thought to have had zero size, and so to have been infinitely hot.But as the universe expanded, the temperature of the radiation decreased.
  • One second after the big bang, it would have fallen to about ten thousand million degrees.This is about a thousand times the temperature at the center of the sun. At this time the universe would have contained mostly photons,electrons,and neutrinos and their antiparticles, together with some protons and neutrons.
  • About one hundred seconds after the big bang, the temperature would have fallen to one thousand million degrees, the temperature inside the hottest stars. At this temperature protons and neutrons would no longer have sufficient energy to escape the attraction of the strong nuclear force, and would have started to combine together to produce the nuclei of atoms of deuterium (heavy hydrogen ), which contain one proton and one neutron.
  • Within only a few hours of the big bang, the production of helium and other elements would have stopped.And after that, for the next million years or so, the universe would have just continued expanding, without anything much happening .