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This Defense Intelligence Reference Document (DIA-08-1003-018), dated 30 March 2010, was produced by the Defense Intelligence Agency as part of its FY 2009 Advanced Aerospace Weapon System Applications (AAWSA) Program. It reviews theoretical approaches to antigravity for aerospace propulsion, drawing on Newtonian physics, general relativity, cosmological dark energy and quantum vacuum effects. The report notes that no current technology can actively control gravity and that many concepts are far from practicable engineering.
“electromagnetic effects”13 pages
UNCLASSIFIED//F811. 8FFll!l*L 1!1!11! t!IIU:!Y However, this isn't the entire story because there are many interesting quantum field theoretic phenomenon that exist outside of that which arises in quantum corrections to Newtonian gravity. In what follows, the recent discovery of antigravity forces that arise within both QED vacuum fluctuation and nonretarded quantum interatomic dispersion force theories in curved spacetime are reviewed. ANTIGRAVITY VIA QUANTUM VACUUM ZERO-POINT FLUCTUATION FORCE Calloni et al. (Reference 61,62) explored the possibility of verifying the equivalence principle for the zero-point energy of quantum electrodynamics (QED). They used semi- classical quantum gravity theory to evaluate the net force produced by quantum vacuum zero-point fluctuations (ZPF) acting on a rigid Casimir cavity in a weak gravitational field. Their analysis assumed the rigid Casimir cavity to be a non-isolated system at rest in the Earth's gravitational field, which is modeled using the standard Schwarzschild spacetime metric geometry, so that they could evaluate the regularized (or renormalized) stress-energy tensor, (r,::: t,, , 11 of the quantized vacuum electromagnetic field between two plane-parallel ideal metallic plates lying in a horizontal plane. (T..'.:: ),..,, encodes the Casimir Effect which has a negative energy density and a negative pressure along the vertical (acceleration) axis between the plates. (See Appendix A for more information about the Casimir Effect.) Their results agreed with the equivalence principle because they showed that quantum vacuum ZPF (that is, virtual quanta) do gravitate because the energy of each ZPF mode is redshi~ed by the factor (-tt,J''' =[1-(2cM !c'r)]"' even though the modes remain unchanged. In other words, the electromagnetic vacuum state in a weak gravitational field is redshi~ed. This effect remains true for strong gravitational fields. The resulting antigravity force (Fc."c, .... ) derived by Calloni et al. is (Reference 62): F, , ~ rr'Ahg Ca,Gr<lv ] SOC d _l in Newtons (N), where A is the area of the plates and dis their separation. Equation (24) states that a Casimir device in a weak gravitational field will experience a tiny (24) push in the upwards direction (that is, the opposite direction with respect to the Earth's gravitational acceleration). This is consistent with the interpretation that the negative Casimir energy in a gravitational field behaves like a negative mass (Reference 63). Fc,,_c;,.," is actually the sum of two separate force terms: the first term arises from the Casimir energy encoded in (T,'.::' t, which is interpreted as the Newtonian repulsive force on an object with negative energy, and the second term arises from the pressure along the vertical (acceleration) axis which is interpreted as the mass contribution of the spatial part of the stress-energy tensor. To evaluate Fc."c,av for the case of any gravitating body of interest, one must replace gin Equation (24) with Equation (2). 11 The angular brackets denote the quantum (vacuum state) expectation value of the stress-energy tensor P''. Also note that stress-energy is synonymous w,th energy-momentum. 19 UNCLASSIFIED//FOAt OFFIQI.Ctk Wlii &••LY
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