2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/91761Various origins of linear and nonlinear Schrodinger equations are discussed in connection with diffusion, hydrodynamics, and fractal structure. The treatment is mainly expository, emphasizing the quantum potential, with a few new observations.34 pages, Latex, references and comments addedQuantum Physicstext