DIA, 2010-2011: dois estudos do AAWSAP avaliam a antigravidade e a “massa negativa” e concluem que nada disso está ao alcance da tecnologia

UNCLASSIFIED//[FOR OFFICIAL USE ONLY, struck through] Defense Intelligence Reference Document Acquisition Threat Support 30 March 2010 ICOD: 1 December 2009 DIA-08-1003-018 Antigravity for Aerospace Applications

Antigravity for Aerospace Applications Prepared by: Acquisition Support Division (DWO-3) Defense Warning Office Directorate for Analysis Defense Intelligence Agency Author: AAP Person 58 Administrative Note COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. This product is one in a series of advanced technology reports produced in FY 2009 under the Defense Intelligence Agency, Defense Warning Office's Advanced Aerospace Weapon System Applications (AAWSA) Program. Comments or questions pertaining to this document should be addressed to [AAP Person 1], AAWSA Program Manager, Defense Intelligence Agency, ATTN: CLAR/DWO-3, Bldg 6000, Washington, DC 20340-5100.

Antigravity for Aerospace Applications Foreword Antigravity effects can be implemented by manipulating spacetime. This paper reviews several different theoretical approaches for exploring the possibility of controlling gravity by generating forces that counteract, or otherwise modify, gravity for the purpose of aerospace propulsion. Einstein's General Theory of Relativity is the theoretical framework guiding this study. The paper also reviews other antigravity approaches via the interaction of quantum theory with gravitation. And it explores the question of which method or technique is best suited for aerospace applications and evaluates the make-or-break issues that limit them.

I. Introduction Gravity is the bane of aerospace transportation. The force of the Earth's gravitational field acts to pull all objects, whether in motion or at rest, downward towards the Earth's surface. Because aerospace transportation involves the motion of vehicles through the atmosphere and/or into space, propulsion engineers are always faced with the requirement that aerospace vehicles will have to carry enough propellant and associated tankage in order to provide enough propulsive thrust to overcome the downward pull of gravity and achieve rectilinear motion. Energy has to be expended by a propulsion system to overcome the force of gravity in addition to providing for rectilinear motion, and the majority of propulsive energy is dedicated to overcome gravity. The aerospace propulsion engineer is faced with two choices for the control of gravity in this regard: passive control and active control. Modern aerospace propulsion technology, which is based on accumulated scientific knowledge since recorded history, can only achieve the passive control of gravity whereby a given propulsion device must develop a thrust that will passively counteract the Earth's gravitational pull, lift a vehicle off the surface, and propel it through the air or into space. Newton's laws of motion and gravity require that the fuel fraction of any aerospace vehicle can never be less than that given by a simple function of the ratio of the vehicle's maximum speed to the speed of its rocket plume, jet, fan, or propeller wake. For example, this limit implies that a single-stage rocket that accelerates to escape velocity must be composed of more than 93 percent fuel. That is because a rocket must accelerate its working fluid from rest (relative to the rocket) up to its exhaust speed. Thus, exhaust speeds for aircraft and chemical rockets are limited by material science, chemical reaction rates, and engineering factors to only a few thousand meters per second. To date, there is no technology that can achieve the active control of gravity. If one could eliminate or otherwise control the Earth's gravity field, then one has the ability to dramatically reduce the amount of propellant, its tankage, and the overall structural size and mass of an aircraft or rocket because there will no longer be any need for these to overcome the pull of Earth's gravity while transporting a payload across the globe or into space. Instead, aerospace vehicles will only need to have the propellant mass and infrastructure necessary to change their kinetic energy from rest to a final velocity necessary to achieve atmospheric flight or space orbit. The Earth's gravitational well will no longer have any impact on aircraft, launch vehicle, or spaceflight dynamics if one were to achieve active gravity control. Aerospace vehicles would merely "levitate" in air and their propulsion systems would be optimized for change-in-velocity missions. However, it is possible to envision a form of active gravity control propulsion that would not require a change in kinetic energy. One of the primary concepts for the goal of affecting gravity is "antigravity," which is a colloquial expression that specifically means the negation or repulsion of the force of gravity. A more general term that encompasses this notion and other possibilities is "gravity control." If antigravity exists, it can be exploited to counteract or nullify the gravitational pull, or attraction, of a planetary (or stellar) body that acts upon a much smaller body. Einstein's General Theory of Relativity gives a prescription for a variety of different antigravity generators. Even Newton's law of gravity offers several different classical prescriptions. Newton's law of gravity can be used to simply nullify the gravity field of one body acting on another body by using a clever arrangement of masses. The theoretical possibility of antigravity also appears in quantum gravity theories, cosmological vacuum or dark energy, and quantum field theory. This report reviews all of these topics. The report will also review the topics of gravity control that include the production of antigravity (self-lifting) forces induced by quantum vacuum zero-point energy and by nonretarded quantum interatomic dispersion forces in a curved spacetime (that is, in a background gravitational field). The reader should bear in mind that many of these concepts are nowhere near having any form of practicable engineering implementation. However, the report will provide theoretical estimates to guide the way toward technological implementation of antigravity.

V. Conclusion: The Way Forward This report has reviewed and analyzed a number of antigravity concepts that are found within Newtonian gravity theory, General Relativity Theory, semi-classical quantum gravity theory, quantum field theory, and nonretarded quantum interatomic dispersion force theory. One found that plausible mechanisms exist within Newtonian and general relativistic theories whereby one could embody a realistic device that produces a significant antigravity force. However, one discovered that there are daunting technical challenges that arise in each of the proposed embodiments. Mechanical embodiments that produce antigravity forces require kilometer-sized apparatus, astronomical-sized masses and densities, or extreme mass velocities and accelerations. There are other subtleties involved, such as the possibility of different forms of matter having a highly nonlinear gravitational permeability, which could dramatically mitigate such large-scale requirements (see item 1 below for further discussion). Negative energy has been produced in the lab in very small quantities. The technologies used for producing negative energy are nascent, and so it will be some time before it can be ascertained whether they are capable of producing the astronomical amounts of negative energy required to generate significant antigravity forces as discussed in Section III-C-2 (see item 2 below for further discussion). Antigravity forces produced by quantum electromagnetic vacuum ZPF or by nonretarded quantum interatomic dispersion forces in a curved spacetime (that is, gravitational field) are very feeble, but there are proposals based on other theoretical and empirical studies which suggest that these forces can be amplified to macroscopic level. However, there are a number of difficult technical challenges to overcome in order to achieve success. Going forward toward the demonstration of an antigravity generator will require the following steps to be taken: • Antigravity via Dipole Gravitational Field Generators: Presently, the technology does not exist to achieve the astronomical mass densities, extreme velocities or accelerations of mass motion, and the large device dimensions required to produce large enough antigravity forces for useful propulsion. The issues are: 1) dense materials, and 2) gravitational properties of matter. Forward (Reference 14) suggests investigating neutron-neutron interactions. One could cool a gas of thermal neutrons from a nuclear reactor to extremely low temperatures using magnetic confinement or magneto-grav itational traps, and concentrate them into a small region through the interaction of the trap's magnetic field with the magnetic moment of the neutrons. The Fermi energy[12] of the bound neutrons limits the neutron density to ~10^-3 kg/m³. However, the formation of putative tetraneutrons[13] or the existence of a superconductive-type phase space condensation will create bosons that do not have this limitation. It turns out that exotic quantum states of matter such as Bose-Einstein (BE) and Fermionic condensates[14] transcend the Fermi energy limit and thus possess highly unusual material properties. BE condensates were first created in 1995 and Fermionic condensates were first created in 2003, but both are still undergoing laboratory exploration. As for the gravitational properties of matter, one knows from electromagnetism that the permeability (µ) of magnetic materials such as iron is anomalously large and nonlinear, which allows for the construction of highly efficient electromagnetic field generators. The gravitational equivalent to the magnetic permeability is a property of matter that is still largely unexplored. A material possessing an anomalously large, very nonlinear gravitational permeability (η) would be useful in the construction of highly efficient, very small scale gravitational field generators. One would expect all materials to have an η that is different from η0 because the atoms comprising any material have quantum spin. Forward [12] In condensed matter physics, this is the energy of the highest occupied quantum state in a system of fermions (that is, spin-½ particles such as electrons, nucleons, or atoms) at zero absolute temperature. [13] A hypothetical stable cluster of four neutrons whereby recent empirical evidence suggests it exists. Readers should consult the technical literature for more information by using "tetraneutrons" as a search term. [14] BE or Fermionic condensates are a macroscopic collection of bosons (spin-1 particles such as nucleons or atoms) or fermions that collapse into the same quantum state when they form at near-zero absolute temperature. (Reference 14) reported that a rough estimate indicates there is a very small difference between η and η0. It is thus necessary to implement a coordinated theoretical program to determine the value of η for all known forms of matter and an experimental program to find materials that might possess anomalously large or nonlinear properties that can be used to intensify time-varying gravitational fields. Forward (Reference 14) also described an unsuccessful experimental attempt to find materials that have the property of converting time-varying electromagnetic fields into time-varying gravitational fields. This speculative property exploits the fact that the magnetic and inertial moments are combined in an atom via the usual quantum angular and spin momentum coupling. Other theoretical and experimental concepts incorporating the use of rotating superconductors are reviewed by Hathaway (Reference 69). Note in particular that Hathaway reviews the emerging experimental observations of Martin Tajmar in which an apparent frame-dragging effect is observed near super-cooled rotating rings as measured by ring laser gyros and accelerometers. At the time of this writing these effects were being reported but not yet independently confirmed. • Antigravity via Negative Energy: The assessment provided in Reference 70 concludes that small amounts of negative energy are already made in the lab, but one does not yet know there is access to larger amounts for extended periods of time over extended spatial distributions for the purpose of producing antigravity. In this regard, the following options for further exploration are proposed: - Squeezed quantum vacuum generators (see Appendix A): A dedicated research program to develop the two negative energy generator concepts described in Reference 70 will need to be established in order to evolve state-of-the-art quantum optics technology towards producing higher magnitudes of negative energy as well as special techniques required to separate out any positive energy fluxes that accompany the negative energy fluxes. Specifically, the Rabeau et al. (Reference 71, 72) and Ries et al. (Reference 73) experimental programs should be followed as a template toward this goal. Quantum optics technology via high power fiber lasers, resonators, amplifier stages, beam conditioning stages, and so forth are rapidly advancing. So research should be conducted in parallel to invent additional ways to produce negative energy via innovative quantum optics. - Casimir effect: Even though the standard electromagnetic Casimir effect is feeble, and thus not likely to contribute to an antigravity engineering program, there are still a number of other electromagnetic and non-electromagnetic Casimir effects described in Appendix A that require further study. These other Casimir effects have not been explored with an eye toward testing them in the lab, and so there could be important new information yet to be discovered. - Moving Mirrors (a.k.a. the dynamical Casimir effect; see Appendix A): Even though this concept is too feeble to produce any useful flux of negative energy, the observable effects due to the change in the boundary conditions (for example, moving mirrors/cavity walls) of quantum fields provide crucial information on the quantum vacuum at the macroscopic level. Theoretical and laboratory efforts are underway to understand the dissipative effects of vacuum fluctuations (Reference 74,75). This dissipation mechanism should induce irradiation of photons, a phenomenon also known as the dynamical Casimir effect. This can be understood both as the creation of particles under non- adiabatic changes in the boundary conditions of quantum fields, or as classical parametric amplification with the zero-point energy of a vacuum field mode as an input state. More recent developments include models for the super-radiant amplification of photons with particular emphasis on its dynamics and the optimization of the involved parameters. Experimental concepts being pursued will try to reveal directly the presence of a non-empty vacuum by using a specifically designed device to amplify the virtual vacuum photons and produce real electromagnetic radiation via the parametric amplification of the vacuum fluctuations in an electromagnetic cavity. The 'amplifier' is a boundary undergoing an oscillation, and hence radiates energy due to the dissipative action against the vacuum photons. This line of investigation could serve as a very useful probe to explore the possibility of generating large fluxes of negative energy. One expects that a laboratory demonstration of the dynamical Casimir effect will occur before 2012. - Dirac field states: As described in Section III-C-1, this involves either the superposition of two single particle electron states or the superposition of two multi-electron-positron states (Reference 41,42). This is still a nascent topic of study in quantum field theory. However, already a great deal of technology is dedicated to the manipulation and storage of electrons and positrons via solid state/condensed matter devices and particle accelerators. This research topic should be supported in order to establish how it could contribute to an experimental antigravity program. - Quantum coherence effects: Other types of quantum coherence effects not already identified or invented should be theoretically developed and explored for the possibility of finding new free-field or interacting field configurations that produce a significant magnitude of negative energy which could be produced by technological means. [Note that Reference 70 showed that static, radially-dependent electric or magnetic fields and gravitationally squeezed vacuum electromagnetic zero-point fluctuations (see items 1 and 3 in Section III-C-1 and Appendix A) are not useful forms of negative energy.] - Detecting Negative Energy in the Lab: Reference 70 identified proposals for observing negative energy in outer space and in the laboratory, but further work is needed to downscale astronomical techniques for use at the lab scale, and there is need to firm up our understanding of how lab detectors will respond to negative energy in situ if one is to exploit it for the production of antigravity forces. A first step in the latter direction was recently proposed by Marecki (Reference 76) who generalized the analysis of the output of balanced homodyne detectors (BHDs). The most important feature of these devices is their ability to quantify the quantum vacuum fluctuations of the electric field because the output of BHDs provides information on the one- and two-point functions of arbitrary states of quantum fields. Marecki computed the two-point function and the associated spectral density for the ground state of the quantum electric field in Casimir geometries, and predicts a position- and frequency-dependent pattern of BHD responses if a device of this type is placed inside a Casimir cavity. The proposed device allows for the direct detection of quantum vacuum fluctuations and provides a spatial mapping of the negative energy contained inside the cavity. This offers a potential new characterization of ground states in Casimir geometries, which would provide an understanding of the negative energy densities present in some regions in these geometries. - Trapping and Storing Negative Energy: Ford and Roman (Reference 20) have only superficially addressed this topic, and there is very little technical literature that addresses it fully. A theoretical program to develop the physics and technology of trapping and storing negative energy will need to be supported, and such a program should be guided by the use of laboratory detectors such as the one proposed in the previous section. However, it is the opinion of the author that free-space negative energy sources appear to be a more desirable option for producing antigravity than stored negative energy. • Antigravity via Quantum Vacuum Zero-Point Fluctuation Force: Calloni et al.'s experimental proposal reviewed in Section IV-A should be funded and performed by a high quality laboratory. • Antigravity via Nonretarded Quantum Interatomic Dispersion Force: Pinto's experimental proposal reviewed in Section IV-B should be theoretically evaluated prior to funding an experiment. This proposal does contain enough rigor and credibility that it warrants a further look.

UNCLASSIFIED//[FOR OFFICIAL USE ONLY, struck through] Defense Intelligence Reference Document Defense Futures 03 January 2011 ICOD: 30 August 2010 DIA-08-1101-023 Negative Mass Propulsion

Negative Mass Propulsion The Defense Intelligence Reference Document provides non-substantive but authoritative reference information related to intelligence topics or methodologies. Prepared by: Technology Warning Division (DWO-4) Defense Warning Office Directorate for Analysis Defense Intelligence Agency Author: AAP Person 72 Administrative Notes: (U) COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. This product is one in a series of advanced technology reports produced in FY 2010 under the Defense Intelligence Agency, Defense Warning Office's Advanced Aerospace Weapon System Applications (AAWSA) Program. Comments or questions pertaining to this document should be addressed to [AAP Person 1] AAWSA Program Manager, Defense Intelligence Agency, ATTN: JUIAF - DI/DWO-3, Bldg 6000, Washington, DC 20340-5100.

Negative Mass Propulsion Summary It is easy to prove that there are negative masses all around us, albeit hidden behind positive masses. But their use for propulsion by reducing the inertia of matter, for example in the limit of macroscopic bodies with zero rest mass, depends on a technical solution to free them from their imprisonment by positive masses. It appears that there are basically two ways this might be achieved: 1. By the application of strong electromagnetic or gravitational fields or by high particle energies; 2. By searching for places in the universe where nature has already done this separation, and from which the negative masses can be mined. The first of these two possibilities is for all practical means excluded, because if possible at all, it would depend on electromagnetic or gravitational fields with strengths beyond what is technically attainable, or on extremely large particle energies likewise not attainable. With regard to the 2nd possibility, it has been observed that nonbaryonic cold dark matter tends to accumulate near the center of galaxies, or places in the universe which have a large gravitational potential well. Because of the equivalence principle of general relativity, the attraction towards the center of a gravitational potential well, produced by a positive mass, is for negative masses the same as for positive masses. Large amounts of negative masses might have over billions of years been trapped in these gravitational potential wells. Now it just happens that the center of the moon is a potential well, not too deep that it cannot be reached by making a tunnel through the moon, not possible for the deeper potential well of the earth, where the temperature and pressure are too high. Making a tunnel through the moon, provided there is a good supply of negative mass, could revolutionize interstellar space flight. A sequence of thermonuclear shape charges would be required to make such a tunnel technically feasible.

1. Introduction If we extend the law of gravity to negative masses, but hold onto the equivalence of inertial and gravitational masses, we have to distinguish between the following four cases, if a test particle is placed near a gravitational field producing mass (Table 1): Table 1. Interactions [Case | Gravitational field producing mass | Mass of test particle | Motion of test particle] 1 + + attraction; 2 + − attraction; 3 − + repulsion; 4 − − repulsion. Under the principle of equivalence if a negative test mass particle would be placed in the gravitational field of earth, it would not fall upwards, as happens in science-fiction antigravity machines. A test particle, regardless of whether it has positive or negative mass, would there always fall down. It would fall upwards only if placed in the field of a large negative mass. A somewhat different situation arises if both masses, the field producing mass and the mass of the test particle, have the same absolute value but are permitted to have different signs. There we have to distinguish between the cases shown in Figure 1. [Figure 1. Forces: case 1 attraction; cases 2 and 3 selfacceleration; case 4 repulsion]

13. Conclusion The purpose of this study is the question as to whether negative mass might exist, and if negative mass propulsion is possible at all. It is unlikely to be possible in the fashion speculated by Forward [13] (but also see Winterberg [17]), where a negative mass is chasing a positive mass without the expenditure of any energy. Rather, it might perhaps be possible through the existence of an ultra-light form of matter with the tensile strength of ordinary matter on a macroscopic scale where positive matter is bound to negative matter, as happens with Dirac spinor particles on a microscopic scale. This is the speculative existence of macroscopic bodies approaching zero rest mass, of importance for space flight because such matter would greatly reduce its energy requirements.

Inserting r0 = 2x10^3 cm, R = 1.74x10^8 cm, εr ≈ 10^10 erg/cm^3, (Pmax/P0) = 5x10^4, one finds that E ~ 2x10^24 erg ~ 5x10^4 kiloton = 50 Megaton. It must be emphasized that this energy must be quite nonuniformly released along the tunnel shaft.