And one more: in a supernova, especially a core collapse supernova, huge quantities of new nuclei are synthesized, very quickly, in the nuclear reactions triggered by the flood of neutrons. While this theory achieved relative success, it was discovered to be lacking in some important respects.
Gradually it became clear that hydrogen and helium are much more abundant than any of the other elements. As a main sequence star ages, the core temperature will rise, resulting in a steadily increasing contribution from its CNO cycle.
In the cores of lower-mass main-sequence stars such as the Sunthe dominant energy production process is the proton—proton chain reaction.
To do that you need stars, which means waiting around for at least billion years. This alternative theory was called a steady state theory and fell out of favor when the cosmic microwave background radiation was detected.
In the 's and 60's the predominant theory regarding the formation of the chemical elements in the Universe was due to the work of G.