cold fission
@aeva it is until it does, then it's not,

@aeva oh god i forgot about bismuth

*edit, explaining the bismuth thing* people thought it was stable until some people figured out it's not, the half life is just a billion times longer than age of universe, https://en.wikipedia.org/wiki/Isotopes_of_bismuth

(i don't do this i just hung around the wrong people)

Isotopes of bismuth - Wikipedia