Triple-Alpha Process: Helium Burning & the Hoyle State

Inside a star's helium-burning core, carbon is forged from nothing but helium — but not in one step. This simulation renders a patch of stellar plasma as real 3D α particles: watch two collide into fleeting, unbound beryllium-8, and watch a third α particle occasionally strike that beryllium within its femtosecond lifetime, capturing through the resonant Hoyle state of carbon-12 that Fred Hoyle predicted in 1954 from the mere fact that carbon exists. Adjust core temperature and plasma density to see the reaction's brutal T-dependence, and toggle the Hoyle resonance off to see why, without it, stars could barely make carbon at all.