2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/86885In recent years Quantum Superstrings and Quantum Gravity approaches have come to rely on non differenciable spacetime manifolds. These throw up a noncommutative spacetime geometry and we consider the origin of mass and a related modification of the Dirac equation in this context. This also throws some light on gravitation itself.8 pages, based on two papers accepted for publication in Int.J.Mod.Phys.EGeneral Physicstext