The tides are caused by electrostatic rings of force which form concentric circles around the line joining two planetary bodies. This causes a constriction effect which squeezes sideways on the planets such that if they were composed entirely of fluid, they would become elongated into ellipsoids. These rings of force constitute double helix alignments of linearly polarized electron-positron dipoles. As in the case of all dipole fields, the tidal force obeys an inverse cube law.