Figure 1: This is a static view of two series atoms or dipoles.

Figure 2: Here we see how they might rotate in-phase.
At apogee, on the left end, we see the electrons are closer together and the charges are more dense. The left end is more negative. The right end of the ellipses is more positive. There are more protons than electrons. The ends of the ellipses have opposite charge. They are dipoles.

Figure 3: Note the pulses when they align in-series. They may also occasionally align momentarily by Brownian motion without the rotation, which is all that is required for gravity.
Static charges can not produce gravity.

When they align momentarily, there is a pulse of series force between the charges. The pulse lasts longer at apogee. Impulse times duration equals force. The charges are closer together when they are at apogee. It is this very short electrical impulse which produces gravity and inertia. The extreme shortness of the pulses explains the weakness of gravity compared to the continuous force between charges.

The dipoles are rotating at 6E15 hertz. This is 6 petahertz. We should be able to make machines to operate at this frequency, in 10-15 years according to Moore's law, to verify this hypothesis.

The attracting electrons and protons are moving in opposite directions. They pass each other at 6E15 hertz squared. If we say the dipoles align for 1/20 of a degree or 1/7200 of a revolution, then we have,
1/(7200)2 * 1/(6.576E15)2 = 1/(2.242E39),
This is the ratio of gravitational to electrostatic Coulomb forces. Gravity is so much weaker than electrostatic force because of the short duration of the in-line interaction of the pulses of force between the in-phase series dipoles.