Maxwell evidently conceived of “empty space” as actually being an “ether” of overlaid positive and negative charge. The charge density of each distribution was the same, and thus the net density was nominally zero. In selected volumes, however, the positive and negative distributions are pulled apart into distinct volumes of “displacement charge”. Since the displaced charges are of opposite sign, they are attracted by an electric force, which Faraday (and Maxwell) modeled as “lines of force” or electric field lines. It requires work to displace the positive and negative charges into distinct regions, and this work equals the energy in the nonzero electric field.
In gravitomagnetic theory (GMT) every sub-lightspeed particle has two primordial components: a Maxwell displacement charge and a similar displacement mass. The energy of the mass is negative, since in theory mass is imaginary, and mass squared is a negative real value. It is suggested that a stable particle results when the total (positive) electric field energy and the total (negative) gravitational field energy sum to zero. In other words, the total work required to form a particle is zero.
Let us calculate the parameters of a stable electron, which consists axiomatically of a spherical shell of charge and a concentric spherical shall of mass. The work to assemble the shell of charge is
Wq=q2/4πε0rq > 0.
And that expended to assemble the shell of mass is
Wm=-Gm2/rm < 0 (since m is theoretically imaginary).
Wq and Wm sum to zero if
rm=-4πε0rqGm2/q2.
Using the classical electron radius, rq=2.82e-15 meters, we find that
rm=6.79e-58 meters.
This is practically a point mass. But it is of course not precisely a point mass, since the gravitational field energy of a point mass would be infinitely negative.