2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36646The Wheeler-DeWitt equation for empty FRW minisuperspace universes of Hartle-Hawking factor ordering parameter Q=0 is mapped onto the dynamics of a unit mass classical oscillator. The latter is studied by the classical Ermakov invariant method. Angle quantities are presented in the same context8 pages, 4 figsGeneral Relativity and Quantum Cosmologytext