A Cloaked Apple, and an Illustration Nobody Asked For
A cloaked apple that looks like a banana sounds like something invented for a pitch meeting. It is not. It is the Defense Intelligence Agency’s own illustrative example, sitting inside a six-page slice of a 2010 report that a Freedom of Information Act (FOIA) request eventually pried loose.
A Request, and What Came Back
John Greenewald, who runs The Black Vault, filed the FOIA request with the DIA on March 23, 2022. The agency’s response letter is dated July 24, 2024, and reached him by email the following day, after which the document went up on The Black Vault’s archive for download. What arrived was six pages titled “Metamaterials In Cloaking Applications,” part of DIA’s “Technology Forecast” series, originally classified SECRET, a level meaning its disclosure was judged capable of causing serious damage to national security, back in 2010. Nothing in the letter explains the more than two years between the request and the release, and no reason is given for that particular timeline.
What the Report Actually Says
The document surveys transformation optics, the practice of engineering metamaterials, materials built to bend light and other waves in ways ordinary materials don’t, so that light travels around an object rather than reflecting off it. It singles out a 2010 presentation by Professor C.T. Chan of the Hong Kong University of Science and Technology at the META’10 conference in Cairo. Chan’s work went past simple concealment: the same technique, the report notes, could make one object appear to be something else entirely. Its example is the cloaked apple rendered to look like a banana. That is stated as research content the DIA was tracking, not as a device the agency built or tested itself.
The Hardware
The report credits Professor Chao Li’s group at the Chinese Academy of Sciences with turning Chan’s theory into a proof-of-concept: a transmission-line simulator, a scaled physical model used to test electromagnetic behavior, operating at 51 MHz across a 10% bandwidth. It also lists parallel work at Duke University, UC Berkeley, the Universitat Autònoma de Barcelona, and the University of Utah, with no frequencies, funding figures, or names attached to any of them. It reads as an inventory of who was working on the problem, not a ranking of which effort mattered most.
What This Establishes, and What It Doesn’t
Read on its own terms, the document confirms that by 2010, illusion-based metamaterial cloaking was a genuine and internationally active research field with working demonstrations, not a paper exercise. It also confirms the limits of that work at the time: the Chinese proof-of-concept ran in a narrow radio-frequency band, not across visible light, and nothing described here approaches general-purpose invisibility. That is as far as the six released pages take a reader. They contain no explicit statement of how DIA itself rated the field’s maturity or what, if anything, it flagged as a concern. The survey describes what other researchers had built. It does not say what the agency concluded from that.
The Withheld Pages
DIA’s release letter cites three FOIA exemptions for the material it kept back. Exemption 1 covers information properly classified under Executive Order 13526, unsurprising given the report’s original SECRET marking. Exemption 3 applies only when a specific statute authorizes withholding a category of information, and the letter does not name which statute it relied on. Exemption 6 protects personal privacy, though whose personal information would appear in a technical forecast about metamaterials is not indicated anywhere in the pages released. These are facts about the redaction. They say nothing about what sits underneath it.
The Silence on Intent
Nowhere in the released text does the DIA say why it commissioned this survey, what it concluded about where the field was headed, or what use, operational or otherwise, it anticipated for cloaking or illusion technology. A document called a “Technology Forecast” implies some forward-looking judgment. None appears in the unredacted pages. It may sit in the sections withheld, or the forecasting function may simply have been the cataloging itself, gathering scattered international research into one place for whoever needed to know it existed. Both readings fit everything that has been released. Nothing in the record says which one is right.