Lamoreux [2].  Milonni et al. [3] showed furthermore that Casimir-plates are being pushed together by the ‘unbalanced ZPE radiation pressure’. It seems that this effect derives from the partial shielding of the interior region of the plates from the background ZP fluctuations of the vacuum EM (electromagnetic) field, suggesting again the real existence of a QV and, in addi tion, of vacuum radiation.  Further, B. Haisch, A. Rueda, and H.E. Puthoff deduced for the first time that the “inertia of matter could be interpreted at least in part as a reaction force originati ng in interactions between the EM ZPF and the elementary charged constituents (quarks and electrons) of matter” [4]. They also accepted that “extensions to include the ZPFs of other fundamental interactions may be necessary for a complete theory of inertia”, which suggests in a wider extent that, in ad dition to Newton’s equation of motion (F=m a), there could be other parameters suitable to being redefined as ZPE-functions [4].  In recent publications [5], [6], H. E. Puthoff and B. Haisch, and A. Rueda calculated respectively the “mass-density equivalent of the vacuum ZPF fields” (10⁹⁷ kg/m³) and the “maximum energy density, space-time can sustain” (10¹¹⁵ J m-³s^-1). The present paper combines Planck values and the mass-density equivalent of the vacuum ZPF fields with gravity, providing a yet unknown equation, which demonstrates that G is a function of vacuum energy and that this energy weakens “mass attraction”.  Furthermore, new equations for inertia are given and ‘electrogravity’ in ‘weak gravity shieldi ng experiments’ is explained as the result of ZPE-manipulation through EM devices. 1. “G” as a Function of QV-ZPF Mass-Density Equivalent. Newton’s law of gravitation: 2 2 1 d m m G F =   , (1) contains the “natural” constant (G), with almost constant value of 6.673x10^-11 m³kg^-1s^-2.  By trying to reveal the meaning of units of G (m³kg^-1s^-2), we found that they can be best represented by the inverse of  “mass-density” (kg/m³) multiplied by the inverse of  “square time”. In this sense, G can be expressed by the following equation: 2 1 1 t G ƒÂ = , (2) where:    ƒÂ = mass-density (kg/m³), and: t = “a certain time” (s). The following step was to assign concrete values to ƒÂ and t, in order to get the most exact value of G possible. Since G is a “universal constant”, the most likely is that both, ƒÂ and t, are themselves constants, so that a medium corresponding to these values had to be found, that is constant in space and time of the whole universe. The only medium that fulfills this condition results to be QV, since it is per definition the most universal medium possible. In addition, the value of ƒÂ had already been calculated by [5] as the “mass-density equivalent of the vacuum ZPE fields” (10⁹⁷ kg/m³). In this sense, finding t in equation (2): 2 / 1 1 1 = G t ƒÂ   , (3) 2