2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/91649Assorted questions: Time as a parameter in Quantum Mechanics. No-Go theorems for a time operator. Localization, time and causality. Causality violation. Localization again. Lesson 1: Evading the troubles: Im E finite. Lights and shadows of a time operator:"Table-top Spacetime" quantum mechanics. Biphotons at Berkeley. Time operator build-up. Good news - bad news. Lesson 2: We need the resonances to tell one.Based on a talk given at the CFIF Workshop:" Time asymmetric quantum theory: The theory of resonances". Lisbon, July 2003Quantum Physicstext