2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/202564The influence of static gravitational field on frequency, wave-length and velocity of photons and on the energy levels of atoms and nuclei is considered in the most elementary way. The interconnection between these phenomena is stressed.LaTeX, 9 pages, no figures, the end of section 5 is modifiedHigh Energy Physics - PhenomenologyGeneral Relativity and Quantum CosmologyPhysics Educationtext