2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/88008To generate a propulsive force without propellant and external couplings, it has been shown that two confined macroscopic and time-varying charge density waves well separated in space are needed. Here, some physical conditions will be proposed to support and maintain these particular collective modes of charge distributions.4 pagesGeneral PhysicsClassical Physicstext