All static forces are conservative. An electrical dielectric of contains forces of opposite charge which only reduces the strength of the static electrical force.
There is no opposite polarity for gravity so the static gravitational force cannot be reduced. Static forces diverge, changing them, effects the entire universe and requires enormous energies. Ref the previous discussion, A magnetic mono pole would diverge and would require enormous energies to produce. No possible with any technology but it is possible that a few may be left over from the formation the universe. All magnetic forces are di-polar, curl, and have a limited range. They do not effect the energy of the universe, and they are not conserved. The magentic, gravitomagnetic ,and nuclear spin orbit forces are not conserved. They come and go as need to conserve the momentum of a system when the original static force fields cannot. >From my book. "The arguments based ontime and distances are not valid. Forthe sake of argument let's first assume that forces propagate instantaneously. The resulting forces are equal andopposite. The movement of local matter,in such a system, immediately affects the distant regions of the universe. No additional forces, other than the originalexchange forces, are required. Thesestatic fields would, conserve momentum through their own actions. In the real universe forces do not propagateinstantaneously. It takes time for thegravitational field of matter to establish itself throughout space. Moving matter immediately experiences theforce of the established gravitational field of distant matter. The fields of moving matter require a finiteamount of time to propagate outward. Fora period of time, distant matter will continue to be attracted to the movedmatter's old position. During thisperiod, the original static forces are not capable of conserving the system’s momentum. Additional forces are required. Michael Faraday discovered that a movingelectrical charge induces a magnetic field. A magnetic field is produced by the dynamic movement of an electricalcharge. Its magnitude is proportional tothe charge's speed. When a movingelectron passes through a changing electrical field, a second magnetic field isproduced. The magnitude of this secondfield is proportional to the rate of change of the external electricalfield. A local force is produced by theinteraction of these two magnetic fields. The action of this local electro-magnetic forcebalances the momentum of the moving electrical charges. " Frank
