Are black holes really the universe’s ultimate enigma, or is there something even stranger out there? Enter gravastars—the “evil twin” of black holes and a cosmic riddle that could redefine our understanding of reality.

Imagine a cosmic soap bubble: a thin, unbreakable shell forged in the furnace of a collapsing star, trapping pure energy in a core so dense it becomes a kind of “super-dense nothingness.” Gravastars are as massive as black holes, as cold as the edge of the universe, and just as invisible—yet they might be the key to answering some of physics’ biggest questions.

From their violent births in supernovae to their potential as the source of mysterious gravitational echoes, gravastars challenge everything we think we know. Are they real celestial objects or elegant mathematical speculation? Watch as Kurzgesagt delves into the science and theory behind these mind-bending entities, explaining why they might offer a solution to black holes’ most frustrating problems—like breaking physics.