Documents / Official release
This Defense Intelligence Reference Document, dated 30 March 2010, was prepared by the Defense Intelligence Agency's Defense Warning Office under its Advanced Aerospace Weapon System Applications Program. It reviews quantum entanglement, nonlocality and EPR experiments, and asks whether nonlocal quantum effects could carry observer-to-observer signals faster than light. The paper describes proposed experiments and an example of real-time Earth control of a Mars rover. It concludes that there is no compelling answer yet and that experimental tests are needed.
From the source: Release of 2026-09-18 Incident: 3/30/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD reviews quantum entanglement and nonlocality with a focus on whether those phenomena might be usable as a means of faster-than-light communication between observers, especially for real-time space operations over interplanetary distances. The report surveys the relevant quantum experiments and no-signal theorems, then examines proposed communication schemes based mainly on momentum-entangled photons, including scenarios involving superluminal and retro-causal signaling. However, it repeatedly acknowledges that the central question remains unresolved experimentally, and it gives substantial attention to the coherence-versus-entanglement tradeoff and other features of standard quantum mechanics that may prevent usable signaling even if non-local correlations are experimentally validated. Overall, the document is an exploratory analysis of whether quantum nonlocality could conceivably support a practical communications application rather than a demonstration of prospective utility.
UNCLASSIFIED/ /FOR OFFl&IAk W&li 8NL¥ a) Pump Figure 4. "Unfolding" the Ghost Interference Experiment The authors point out that there is a simple way of thinking about momentum entanglement measurements involving entangled photons. It can be shown from Snell's Law and conservation of momentum in the crystal that if one photon has a small momentum that causes it to be slightly deflected to the right of the pump beam by an angle 0, then the twin entangled photon will be deflected to the left by the same angle 0, a situation reminiscent of reflection from a mirror. This allows the experiment to be "unfolded" by replacing the effective reflection by a straight-through path, as shown in Figure 4. The point of the unfolding is that the entangled photons behave exactly as would be the case if the direction of the deflected photon was reversed, so that it originated at the detection point D1, passed through one or two slits at C and D, and produced a one or two slit interference pattern at X2 detected by D2. Why is the coincidence needed? First, it should be clear from Figure 2 that detector D2 detects not only the entangled twins of the photons that pass through the slit openings, but also the entangled twins of the much larger number of photons that are stopped by the opaque parts of the slits. Therefore, without coincidences, no interference pattern could possibly be observed at X2, Moreover, one can see from Figure 4b that detector D1 behind the slits receives light in a very localized region, and if it were moved vertically in the diagram, the interference pattern at D2 would be shifted, with maxima becoming minima and vice versa. Without coincidences requiring a particular location for the detection at D1, the D2 distribution would have to average over all possible D1 positions, washing out the two-slit interference pattern. Therefore, because of the geometry used, the Ghost Interference experiment required a coincidence to observe a two-slit interference pattern like the one shown in Figure 3a. UNCLASSIFIED/ /POil orr1e1Jct U91! er~t I 8
Not linked to a story yet.
Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 32 pages are in the text index: search them above, or from the library's search.