DIA, 2010: estudo do AAWSAP projeta comunicações por ondas gravitacionais através da Terra e imagina vigilância e propulsão com elas

UNCLASSIFIED//[FOR OFFICIAL USE ONLY, struck through] Defense Intelligence Reference Document Acquisition Threat Support 6 April 2010 ICOD: 1 December 2009 DIA-08-1004-005 High-Frequency Gravitational Wave Communications

High-Frequency Gravitational Wave Communications Prepared by: Acquisition Support Division (DWO-3) Defense Warning Office Directorate for Analysis Defense Intelligence Agency Author: AAP Person 77 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.

High-Frequency Gravitational Wave Communications Summary • Fourteen laboratory high-frequency gravitational wave (HFGW) generators (or transmitters) have been proposed in the past 45 years in peer-reviewed journal articles. • The most promising laboratory HFGW generators are those that utilize very large numbers of sub-microscopic radiation elements. • The Piezoelectric Approach to HFGW generation is best for the proof-of-concept test and the proposed IR-excited Molecules Approach is best for an operational communications HFGW transmitter. • Ten different HFGW detectors (or receivers) have been proposed since 1978 and reported in peer-reviewed journal articles. • Several different HFGW receivers can be utilized for communication, but the proposed Li-Baker detector (plans & specification development in Appendix B) shows the most promise (underlying concept in Appendix C). The Li-effect, upon which the Li-Baker detector is based, is not so new that it is untested in the literature. At least nine peer-reviewed research publications concerning the theory have appeared following the initial peer-reviewed article by Li, Tang and Zhao (1992). • Because HFGW communications are carried on an extremely narrow beam directly through the Earth, there is a very low probability of interception. • Theoretical results confirm that the Li-Baker detector is photon-signal limited, not quantum-noise limited—that is, the Standard Quantum Limit is so low that a properly designed Li-Baker detector can have sufficient sensitivity to observe HFGWs of amplitude A ≈ 10^-32 m/m. • Utilizing the IR-excited Molecules HFGW generator approach and the Li-Baker detector, the theoretical information-transfer rate over 7,000 km of distance, beamed directly through the Earth, is about 1.9 x 10^6 bits per second. • A means of propagating a Frequency Time Standard may be one viable early low-bandwidth application for HFGW communications. • HFGW sources on the Earth, the Moon, and Mars may act as reference standards for interplanetary navigation, with the advantage that they cannot be shielded or shadowed by planetary masses. Plasma interference seen at planetary entry would be eliminated, and precise charting of Lagrangian points would be possible.

1.0 Introduction 1.1 INTRODUCTION Of the applications of high-frequency gravitational waves (HFGWs), communication appears to be the most important and most immediate. Gravitational waves have a very low cross section for absorption by normal matter, so high-frequency waves could, in principle, carry significant information content with effectively no absorption unlike electromagnetic (EM) waves. Multi-channel HFGW communications can be both point-to-point (for example, to deeply submerged submarines) and point-to-multipoint, like cell phones. HFGWs pass through all ordinary material things without attenuation and represent the ultimate wireless system. One could communicate directly through the Earth from Moscow in Russia to Caracas in Venezuela—without the need for fiber optic cables, microwave relays, or satellite transponders. Antennas, cables, and phone lines would be things of the past. A timing standard alone, provided by HFGW stations around the globe, could result in a multi-billion dollar savings in conventional telecom systems over ten years, according to the recent analysis of Harper and Stephenson (2007). The communication and navigation needs of future magneto hydrodynamic (MHD) aerospace vehicles, such as the MHD aerodyne (www.mhdprospects.com), which is high in electromagnetic interference, similar to plasma interference seen at reentry, would be another possible applications area for HFGW communications. 1.2 DEFINITION OF HIGH-FREQUENCY GRAVITATIONAL WAVES Visualize the luffing of a sail as a sailboat comes about or tacks. The waves in the sail's fabric are similar in many ways to gravitational waves (GWs), but instead of sailcloth fabric, gravitational waves move through a "fabric" of space. Einstein called this fabric the "space-time continuum" in his 1915 work known as General Relativity (GR). Although his theory is very sophisticated, the concept is relatively simple. This fabric is four-dimensional: it has the three usual dimensions of space-east-west, north-south, and up-down-plus the fourth dimension of time. Here is an example: we define a location on this "fabric" (Einstein, 1916) as 5th Street and Third Avenue on the fourth floor at 9 AM. No one can see this "fabric," just as no one can see wind, sound, or gravity. Nevertheless, those elements are real, and so is this "fabric." If one could generate ripples in this space-time fabric, many applications would become available. Much like radio waves can be used to transmit information through space, gravitational waves could be used to perform analogous functions. Gravitational waves are the subject of extensive current research, which so far has focused on low frequencies. High-frequency gravitational waves, as defined by physicists Douglass and Braginsky (1979), are gravitational waves having frequencies higher than 100 kHz. Low-frequency gravitational waves (LFGWs), such as those detectable by interferometric GW detectors (for example, the Laser Interferometer Gravitational Observatory, or LIGO) are not applicable to communications due to their very long wavelengths, often thousands of kilometers in length and, even more importantly, the inability to generate them effectively in the laboratory. Furthermore LFGW detectors cannot detect HFGWs (Shawhan, P. S., 2004).

4.0 Future Potential 4.1 DEVELOPMENTAL ROADMAP A development roadmap is suggested here for the application of High Frequency Gravitational Waves (HFGWs) in the field of communications. The development roadmap should be twofold: • Theoretical work should continue on HFGW transmitters (generators) and receivers (detectors). • Experimental devices should be built and tested in the laboratory and then transitioned over to a practical communications system. A suggested developmental roadmap schedule and phasing timeline is included as Figure 24. Theoretical research is always an ongoing enterprise, but it is especially important to encourage work in the development of experimental approaches aimed at demonstrating laboratory generation and sensing of gravitational waves for the next few years. This is the kind of academic work that is best done in a research university setting, at least for the next ten years or so, until laboratory experiments can verify laboratory generation. Without early confirmation the technology will not gain widespread acceptance and move forward. [Figure 24: timeline chart by decade (201X to 204X) with phases of experimental research, prototype development, device development, applications development, and first applications delivery, production and upgrades, separated by go/no-go milestones] Figure 24. HFGW Com Space Application Development Roadmap, Estimated Timeline The most benefit would come from a coordinated effort spread over a number of different universities. Wherever possible, pre-existing assets should be utilized to stretch funding as far as possible. For example, if synchrotron light is needed to verify the Gertsenshtein effect and the Li-effect, a survey of existing national synchrotron light facilities should be part of the funded effort to find an appropriate host facility. The funding activity—that is, the National Science Foundation—would have the overall responsibility to coordinate this activity in an ongoing manner, through proposal review, contract awards, and progress reviews, and the approach should be flexible enough to allow the redirection of funding should a particularly promising new technology or invention move to the forefront. Assuming that positive laboratory results can be achieved and peer reviewed in a 10 to 12 year timeframe, the next step would call for a period of prototype development, in which the device physics and engineering needed to support the technology could be matured. As prototypes show promise they could be transitioned to device development, the first time that industry would likely enter the field. Once the individual devices required to support GW communication technology—for example, GW generators and GW sensors—are in place, at that point it will be possible to begin full-scale development of systems applications. This is a conservative timeline, based on scaling from the development of previous technologies. If breakthroughs materialize, or if the pace of technological development quickens, progress may certainly occur more quickly than this. 4.2 HFGW COMMUNICATIONS PREDICTIONS TO 2050 In what follows, with an eye to the future, extrapolations are made concerning the development of a HFGW communications technology into the far future (for example, 2050 and beyond). It is difficult to predict even ten years in advance to the time when we expect to have the results of the proof-of-concept test (or "Bell-Watson" experiment) are available and the immediate applications to HFGW communications completed. Speculation beyond that time will be contingent upon advanced development of FBAR crystals, new materials within the toroidal waveguides, and so forth, or even entirely new approaches such as those proposed by G. Fontana, V. Rudenko, R. Chiao, et al. No doubt the Li-Baker detector performance can also be greatly improved with stronger magnetic fields, more intense Gaussian beams, and better baffles as well as new detector designs yet to be developed possibly based upon theories developed at Birmingham University, INFN Genoa and The National Astronomical Observatory of Japan. Optimum designs of communication channels, bands and modulation are also be anticipated. Many of these advanced concepts were discussed at the 3rd HFGW Workshop in Huntsville in February 2009. Nanotechnology advances will allow for the fabrication of smaller and smaller HFGW transceivers having millimeter dimensions and milliwatt power requirements by 2050 and "Radio ID" or rather "HFGW ID" nanochip tags may be ubiquitous. Gravitational wave transmissions would also have the advantage of being able to pierce the protective plasma shielding that may in the future be routinely used to protect the crew aboard manned vessels—that is, communications through artificial magnetospherics, a technological limit of RF communications. 4.3 INTERPLANETARY NAVIGATION AND GEOID MAPPING TO 2050 While there is no doubt that stellar tracking will remain the primary source of navigation for space missions in the foreseeable future, as introduced in Section 3.4.2, HFGW may also prove useful in conjunction with RF in providing a navigation aid for interplanetary missions (with no planetary shielding) by mapping geoids in interplanetary space via long baseline navigation. For instance, if there were one GW source on Earth, and one GW source on the Moon, such a pair of GW sources would provide relative beacons for missions to Mars that could serve multiple roles as navigation beacons, communication relays, and in conjunction with RF signals, map geoids via relative time difference of arrival signals. Very Long Baseline Navigation could be achieved by placing a source on Earth and one GW source on Mars for a baseline that would most often be very widely spread with respect to the outer planets, for outer planetary missions. See Figures 25-27 for a number of different navigation beacon pair options. [Figures 25 to 27: diagrams of a GW pair on Earth as used by a lunar mission; a GW pair on Earth and on the Moon as used by a mission to Mars; a GW pair on Earth and on Mars for an outer planetary reference pair] 4.4 OTHER POSSIBLE HFGW APPLICATIONS The most stunning advances in HFGW applications will probably not be in communications, but in the remotely HFGW-generated nuclear fusion, HFGW propulsion and HFGW surveillance. If an ultra-high-intensity HFGW flux impinges on a nucleus, it is possible that it could initiate nuclear fusion at a remote location, or mass disruption. Also it may be possible to create radioactive waste-free nuclear reactions and energy reactions (Fontana, G. and Baker, R. M L, Jr. 2007). As they suggest: "At high amplitudes, GR (Gravitational Radiation) is nonlinear, thus we might expect a departure from geometric optics. Fortunately, the problem has been already theoretically examined and the resulting effects are found to be advantageous. Nonlinearity improves the focusing process and h goes to one in finite time, producing a singularity "regardless" of the starting, non-focused amplitude of the impinging gravitational wave (Corkill and Stewart, 1983; Ferrari, 1988a; Ferrari 1988b; Ferrari, Pendenza and Veneziano, 1988; Veneziano, 1987; Szekeres, 1992). The effect of a Δh = 0.995 pulse of HFGWs on the couple formed by a deuterium nucleus and its electron is the reduction of their relative distance by a factor of 200. If this distance reduction is effective for a few picoseconds, then the two nuclei of a deuterium molecule can fuse and give an He atom plus energy, which is the usual nuclear-fusion process in a star. " HFGWs could theoretically be used for propulsion and control of the motion of objects such as missiles, missile warheads, spacecraft, and asteroids, and remote control of clouds of hazardous vapors. Gravitational field changes by one or more HFGW generators could urge a spacecraft in a given direction, causing a lower static gravitational field in front of a vehicle (it "falls" forward) and a higher one behind (providing a "push"). The concept is that the mass essentially "rolls" down a "hill" produced by the static g-field; that is, potential energy increase of a mass is provided by the energetic HFGWs. The magnitude of the static g-field is proportional to the square of the HFGW frequency (Landau and Lifshitz, 1975, section 108, page 349). Specifically: "Since it has definite energy, the gravitational wave is itself is the source of some additional gravitational field (static g-field). Like the energy producing it, this field is a second-order effect in the h_ik. But in the case of high-frequency gravitational waves the effect is significantly strengthened: the fact that the pseudotensor tik is quadratic in the derivatives of the h_ik introduces the large factor)...-2. In such a case we may say that the wave itself produces the background field (static g-field) on which it propagates. This [static g] field is conveniently treated by carrying out the averaging described above over regions of four-space with dimensions large compared to A. Such an averaging smooths out the short-wave "ripple" and leaves the slowly varying background metric (static g-field)." (Brackets and underline added for clarity and emphasis.) Such an application must also await the future development of very high-intensity HFGW generators. A novel means of imaging or HFGW surveillance might be developed in future to establish a system to allow for observing activities and materials in three dimensions, within and below structures and within the Earth and its oceans. Gravitational waves, including HFGWs, pass through most material with little or no attenuation; but although they are not absorbed, their polarization (Li and Nan, 2009), phase velocity (causing refraction or bending of gravitational rays), backscatter, and/or other characteristics can be modified by a material object's texture and internal structure. For example, the change in polarization of a GW passing through a material object is discussed in Misner, Thorne, and Wheeler (1973): "In the real universe there are spacetime curvatures due not only to the energy of gravitational waves, but also more importantly to the material [objects and structures] content of the universe... its wavelength changes [based on gravitational red shift] and [the gravitational wave] backscatters off the curvature to some extent. If the wave is a pulse, then the backscatter will cause its shape and polarization.... " It is difficult to theoretically establish the actual magnitude of the changes, especially at very high frequencies (10^14 Hz and higher) and to quantify them prior to HFGW generation/detection laboratory experiments. 4.5 2050 AND BEYOND The phases of human space exploration may be divided into the following phases: • Epoch 1 - Interplanetary Exploration • Epoch 2 - Interstellar Exploration • Epoch 3 - Intergalactic Exploration • Epoch 4 - Universal Exploration Each phase will have its own challenges and opportunities, but one can certainly speculate that the human need for connectedness and communication knows no bounds. So any scope of expansion beyond Epoch 1 will have enormous challenges in the area of communication. The vast distances involved will require some form of communication that entails faster-than-light (FTL) propagation. While this is a highly speculative area, such schemes have been proposed for FTL HFGW. Both Fontana and Meholic (unpublished reports) have proposed models of the universe, such as the trispace model, in which subluminal or luminal gravitational waves may couple into a super-luminal "parallel universe" inside which FTL speeds are possible. Such as scheme would be required to communicate between star systems and galaxies if humankind is to maintain any type of cohesive civilization. Without communications we have a history of fractured civilization, and we slip into becoming our own worst enemy. Universal communication holds the lofty promise of universal peace.