2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/210054We discuss two space-time models: one is expanding, the other is static. They are both derived from Schwarzschild's exterior solution. But they differ in the implementation of the parallelism at a distance and the choice of their master frame of reference.16 pagesGeneral Relativity and Quantum Cosmologytext