2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/100656The quantum nature of a black hole is revealed using the simplest terms that one learns in undergraduate and beginning graduate courses. The exposition demonstrates -- vividly -- the importance and power of the quantum oscillator in contemporary research in theoretical physics.13 pages, no figs. v2: minor typos corrected. conclusions unchangedGeneral Relativity and Quantum CosmologyAstrophysicsQuantum Physicstext