2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148178We prove the title.34 pages, RevTeX v. 2.0 or 2.1, 3 Postscript figures appended, June, 1992. (Updated version, July 30, 1992: differs from original by modifications in references.)High Energy Physics - TheoryGeneral Relativity and Quantum CosmologyHigh Energy Physics - PhenomenologyGott Time Machines Cannot Exist in an Open (2+1)-Dimensional Universe With Timelike Total Momentumtext