When a massive star collapses at the end of its life, it unleashes one of the most violent explosions in the universe. But here's what makes supernovae genuinely strange: almost all the energy released vanishes. Of the total energy liberated in a core-collapse supernova, roughly 99 percent escapes as neutrinos, ghostly particles that barely interact with matter at all. The visible light and kinetic energy of the expanding debris that astronomers can actually observe and photograph account for just 1 percent of the total output. This counterintuitive split has shaped how astrophysicists understand stellar death and the mechanisms powering these cosmic catastrophes. The invisible neutrino flood carries away most of the gravitational potential energy released when a stellar core compresses to neutron-star density. Understanding where that energy goes has been central to supernova physics for decades.