@georgetakei@universeodon.com @ecsd@commons.whatiwanttoknow.org Really, the claim that lead, and uranium-238 emerge from supernovas is itself faith-based. It's different from religion because nobody's threatening us if we don't believe it, but we truly don't know where those elements come from. No model of nuclear fusion that I know of can proceed past iron. Iron doesn't produce a net positive energy when fusing, so there's no more fusion reaction to fight against the crushing gravity. That's as far as it gets. At that point, our mathematical models hit undefinable asymptotes, as the energy density of the collapsing star goes to infinity.

I'm pretty sure that a neutron star can form through simple Newtonian laws of gravity, where the only thing keeping the star from collapsing further is the Pauli exclusion principle. There are also white and brown dwarves, which are basically balls of iron. But a mathematical model for the creation of uranium in the massive chaotic energy blast of a supernova just doesn't exist. As far as I know all they can say is "Uh, 238 protons just randomly happen to smack into each other, and just happen to be ejected away from the explosion, and just happen to drag 238 electrons along with them. Along with every other value of N protons. I guess."

I suppose some people might have a working model for a heavy metal forming in a supernova, but it's faith-based for me. I just don't care where lead or uranium 238 came from. Supernova's my best guess for uranium, but why would I have to know for sure?