2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34655Two popular attempts to understand the quantum physics of gravitation are critically assessed. The talk on which this paper is based was intended for a general particle-physics audience.19 pages. Talk given in the meeting "What comes beyond the standard model?", Portoroz, Eslovenia, 12-17 July 2003General Relativity and Quantum CosmologyHigh Energy Physics - Theorytext