Documents / Report
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.
“The Advance”4 pages
UNCLASSIFIED//FIHl 8FFHil.t.k Wfili IH.k\f are not electromagnetic in nature; that is to say they are non-Maxwellian, and so the perfect-conductor boundary conditions do not apply to them. It turns out that complete manifolds exhibit what is called the topological Casimir effect for any non-Maxwellian fields. In order to define boundary conditions for other fields one replaces the conductor boundary conditions and Minkowski spacetime by a manifold of the form ~H x I (that is, a product space), where ~H is the real line defining the time dimension for this particular product space and I is a flat 3-dimensional manifold having any one of the following topologies: ~H 2 x 51, :H x T2, T3, :H x K2 , and so forth, ~H being the real line that defines any linear space dimension (for example, ~H = line, ~~ 2 = 2-dimensional plane), T 11 being then-torus, K2 the 2-dimensional Klein bottle, S1 the circle, and so forth. The case I = ~H 2 x 5 1 has the closest resemblance to the electromagnetic Casimir effect, the difference being that instead of imposing conductor boundary conditions, one imposes periodic boundary conditions on some of the space coordinates in the 3- dimensional manifold. When imposing this topological constraint on the field theoretic calculation of the topological Casimir effect (for linear massless fields), one finds that the generic expression for the energy density is also f'n: = -Ahc I d 4 , where A= ±d,( 1-i:2 /90), d1 is the number of degrees of freedom (for example, helicity states) per spatial point, the plus sign holds for boson fields (giving a negative energy density) and the negative sign for fermion fields (giving a positive energy density). If one were to admit spin structure in the manifolds described above and the field is spinorial, then there is another important subtlety that must be taken into account when evaluating r'.:i. However, this introduces an additional complexity involving the relationship between the spin structure and the global structure (that is, the configuration space or fiber bundle) of the field in question whereby the topology not only of the base manifold, but of the fiber bundle itself has an effect on T,.~:.·. In addition to this, there are (compactified) extra-space dimensional quantum field (that is, D- Brane or "brane world") analogs of the Casimir effect yet to be explored. But a detailed consideration of these is beyond the scope of this report and will be left for future investigation. As a final note, one points out that the methods used to obtain the electromagnetic 1'.'.'.~· between parallel plane conductors can also be used when the conductors are not parallel but are joined together along a line of intersection. If the conductors have curved surfaces instead, then one obtains results that are similar to the case of intersecting conductors. These geometries have also been evaluated for the case of dielectric media. These particular cases will not be considered further since there are technical subtleties involved that complicate the calculations and application of the different approaches. This topic will also be left for future investigation. DYNAMICAL CASIMIR EFFECT: MOVING MIRRORS Negative energy can be created by a single moving reflecting (conducting) surface (a.k.a. a moving mirror). A mirror moving with increasing acceleration generates a flux of negative energy that emanates from its surface and flows out into the space ahead of the mirror (Reference 37,90). See Figure 5 (below) for an illustration of this effect. This is essentially the simple case of an infinite plane conductor undergoing acceleration 32 UNCLASSIFIED/ ,'P'91t 9P'P'l@lit.ls l!l!il! 8111!¥
Not linked to a story yet.
Report, from the dia collection. The PDF is mirrored here; the original link is above. 44 pages are in the text index: search them above, or from the library's search.