2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/137308The physical non-existence of gravitational waves (GW's) as a consequence of the non-existence in general relativity (GR) of physically privileged reference frames, and of the ``plasticity'' of relativistic notion of a coordinate system.5 pages, LaTeXGeneral Physicstext