2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47301This century has seen a dramatic increase in observational possibilities of the physics of the universe. Several of the very recent new developments with emphasis on the particle physics aspect and in particular Gamma-Gamma interactions are briefly discussed in this talk.14 pages, invited talk at the Gamma-Gamma conference ``Photon '97'', Egmond aan Zee, The Netherlands, May 1997High Energy Physics - Phenomenologytext