2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33823We use Padoa's principle of independence of primitive symbols in axiomatic systems in order to discuss the mathematical role of time and space-time in some classical physical theories. We show that time is eliminable in Newtonian mechanics and that space-time is also dispensable in Hamiltonian mechanics, Maxwell's electromagnetic theory, the Dirac electron, classical gauge fields, and general relativity.LaTeX, 12 pages, no figures. This is a new versionGeneral Relativity and Quantum Cosmologytext