> Oh sure, we can wave our hands at it and invoke the mass-energy relation from GR, but this doesn’t “pop out” of the Standard Model in any sense. Mass-energy

> Oh sure, we can wave our hands at it and invoke the mass-energy relation from GR, but this doesn’t “pop out” of the Standard Model in any sense. Mass-energy equivalence, a.k.a. E=mc^2, is special relativity. It's fundamentally linked with our understanding of electromagnetism. Physics students generally learn about special relativity before they get to quantum mechanics. This is undergraduate physics level material.