You assume that my answer “supernovas” is the only answer.
Evidently I should have been more explicit: One source of Au is supernovas.
Evidently I should have been more explicit: One source of Au is supernovas.
I'm going to (politely) disagree with you there: “Conventional” astrophysics only recognized supernova building of the elements (above the Fe and Ni isotopes) and stellar fusion->collapsing star->layered “burning” for isotopes past the 3-alpha carbon “bottleneck”. And each step of that stellar fusion and collapse adds millions (billions ?) of years to each lifetime of each isotope that is created. Making it less and less and less likely that the elements were actually formed that way.
On a one-by-one basis, the "conventional theory" is correct: It works in the mathematics, it works at the individual atomic level of each individual binding energy and each individual decay rate and fusion cross-section, it works in the laboratory as each individual particle accelerator results as a new isotopes are deposited on the collectors one by one. And all of those steps are (by themselves) correct: we can establish that atoms (isotopes) are built up that way. I've made atoms that way myself. I've burned atoms that way myself.
But.
There must be some other process where by all of the isotopes and atoms we know by measurement are present on earth have been built. Created. Formed. Fused up. Or fused up and eventually fissioned back down.
We just cannot build enough isotopes in the "conventional wisdom" way, then transport those finished gold atoms across space between the stars fast enough to get enough of them here inside earth's crust to make a single ounce of gold. Much less a single Holy Grail. 8<)