2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55847A new force on the magnetic dipole, which exists in the presence of both electric and magnetic fields, is described. Its origin due to the `hidden momentum', implications and possible experimental tests are discussed.6 pages, latex. A shorter version of this article, but with two figures, appeared in Nature, vol. 387, 558-559 (5 June 1997)High Energy Physics - TheoryQuantum Physicstext