1998ApJ...509L...1B

The energy released in the synthesis of cosmic ⁴He from hydrogen is almost exactly equal to the energy contained in the cosmic microwave background radiation. This result strongly suggests that the ⁴He was produced by hydrogen burning in stars and not in the early stages of a big bang. In addition, we show that there are good arguments for believing that the other light isotopes, D, ³He, ⁶Li, ⁷Li, ⁹Be, ¹⁰B, and ¹¹B, were also synthesized in processes involving stars. By combining these results with the earlier, much more detailed work of Burbidge et al. and of Cameron, we can finally conclude that all of the chemical elements were synthesized from hydrogen in stars over a time of about 10¹¹ yr.