With the above model in mind, we interpret Podkletnov’s famous "weak gravitation shielding experiment” as the obvious result of QV manipulation with the aid of E.M. fields, produced by a spinning superconductor. In effect, it seems that the fields induced by the superconductor and/or the coils used for levitation, did increase local ZPR, probably by uploading photons from E.M. fields to QV. At that point, according to eq. (4), the higher ZPR should have reduced gravity, which was effectively observed by Podkletnov 4 and later also by Li 5 and several others.

This means that, it was not the superconductor itself that affected gravity, but the resulting E.M. fields. Probably, a flow of photons from spacetime to QV takes place if strong E.M. fields interact mutually, e.g. by making one field rotate inside another as in 4. The resulting “friction” between both fields could provide the necessary energy to upload photons from spacetime fields to QV, thus increasing local ZPR and reducing gravity according to eq. (4).

This principle suggests further that ZPR is not uniform in the universe, but that there could be many local phenomena that increased or decreased vacuum energy, making therefore decrease or increase respectively local gravity. The universe can be in this sense understood at least as a giant gravity device via QV. The expansion of the universe could be so, at least in part, interpreted as the result of ZPR repulsion on matter. Emerging ZPR in intergalactic space could explain intergalactic voids as well as global dispersion of the universe.

To alter ZPR, we could use any kind of device or system, able to create a photon flow from QV to spacetime and/or vice-versa. It seems at this stage easier to weaken gravity by making interfere spinning intense E.M. fields mutually or flooding tiny spaces with large amounts of photons 11, than to increase gravity by contrary means.

Anyhow, to increase gravity, it is necessary to extract photons from QV. May be black holes, neutron stars and other dense objects do produce or absorb some radiation of this kind. By compressing supercold matter (Bose-Einstein condensate), instead of obtaining fusion processes as in a conventional hydrogen bomb, we already suggested in 12 that it should be able to create superdense matter. Arranging this matter in devices, it should be able to download photons from QV in order to increase local gravity. A spacecraft equipped with a combination of several of the above-mentioned technologies, should be able to navigate without the need of any propulsion, at least in the proximities of celestial objects.

All the above-mentioned are methods dedicated to alter locally the Universal Gravitation Constant “G”. But the right component of eq. (4), consisting of “mass attraction”, is the phenomenon that, in principle, induces vacuum reaction (left component). This means that, apart from vacuum reaction, masses attract mutually by some sort of “gravitational field” or “spacetime geometry” as predicted respectively by quantum field theories and general relativity. Therefore, another way to alter gravity, would be manipulating such fields or geometries - a theme that is out of the scope of this paper.

The novelty of eq. (4) is that it demonstrates that gravity is not really subjected to any kind of constant, but that it is the result of the balance between gravitational attraction and vacuum repulsion on spacetime objects subjected to ZPR. Nature has probably provided this apparently complex system to allow a more stable universe, not subjected to unbiased and/or infinite field intensities and/or accelerations 1. A universe without QV component would probably be a very chaotic place if it had ever existed at all.