The cosmos harbors many mysteries, but few capture our imagination as completely as black holes, regions of spacetime where gravity so dominates that nothing, not even light, can escape once it crosses a critical boundary. They represent the ultimate triumph of gravity over every known counter-force. When matter is compressed into an extremely small volume, general relativity predicts spacetime curvature so severe that it creates what looks, to outside observers, like a “hole” in the fabric of reality. (The geometric picture is subtler, but the metaphor is serviceable.)