2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/168561A class of time independent and physically meaningful Hamiltonians leads to evolution of observable quantities whose Ehrenfest times are arbitrarily large. This fact contradicts the popular claim that the true chaos is in quantum mechanics excluded by first principles.completely rewritten; another physical example but with the same mathematicsQuantum Physicstext