Almost four centuries after Newton's discovery, we are able now to unravel the gravity-enigma.
Gravity IS NOT a separate fundamental interaction in Nature.
Gravitational factor G is just another expression of the remaining dynamical (and/or) electrodynamic physical quantities, as shown below:
G = F * r2 * m-2. (Newton's law of gravity; note that Gu = 1040 GNewton)
G = f * a = f2 * c = f3 * r . (Unified-Physics dynamical definition of gravity)
G = f2 * H2 = k2 * E2 = (d/dt)2H2 = Laplacian E2. (Unified-Physics electrodynamical definition of gravity)
(For more details, compare Figures 3 and 5 form Part 4 of my articles "Consequences of the Unification in Physics".)