he unclassified 1965 paper “Communication with Extraterrestrial Intelligence” by Lambros D. Callimahos, presented during a panel at the IEEE Conference on Military Electronics, outlines a detailed roadmap for interstellar communication, indicating that scientific groundwork for extraterrestrial contact has already been deeply considered by the U.S. intelligence community.
A New Scientific Orthodoxy
At the outset, Callimahos declares a striking premise:
“We are not alone in the universe.”
This assertion, framed as a given rather than a theory, positions the document outside speculative fiction and firmly within operational preparation.
The author quotes astronomical estimates suggesting that up to one billion civilizations could have emerged within the known universe. Dr. Frank D. Drake, among others, is cited to support this figure, and the focus then turns to an immediate practical question: If intelligent life is so probable-
“Where is everybody?”
The implication is not whether intelligent extraterrestrial life exists, but how we might reach or be reached by it.
Strategic Listening and the Hydrogen Frequency
The document centers on Project Ozma, a real scientific effort to detect extraterrestrial signals. Its focal point was the frequency 1420.405752 MHz-the radiation signature of neutral hydrogen.
According to Callimahos, this choice was intentional. Hydrogen permeates the galaxy and any species capable of understanding radio theory would likely recognize it as a universal reference point.
The author posits that advanced civilizations might be broadcasting from afar using this or similar frequencies, possibly with technologies superior to ours-masers, lasers, or hypothetical “rasers.” There is even speculation about modulation via neutrinos, a method humans have not yet mastered.
Geometric Messages and the Anatomy of First Contact
In describing how first contact might unfold, Callimahos outlines attention-getting sequences based on mathematical logic: natural numbers, primes, and geometric constructs such as the Pythagorean Theorem.
A “raster message” is included in the document-a hypothetical binary transmission that, when arranged correctly, forms visual symbols.
“The erect, two-legged beings illustrated are obviously bisexual and mammalian…”
Callimahos interprets these images to suggest the beings’ chemical composition, planetary origin, physical appearance, and technological capability-including that they have already visited Earth.
He describes a series of dots forming images of humanoid figures, planets, atoms, and numeric sequences-all meant to minimize ambiguity and optimize intelligibility across species.
Learning to Speak in “Venerean”
The heart of the document is an elaborate constructed message-a staged series of transmissions from a hypothetical extraterrestrial source.
Across 30 transmissions, the message begins with an enumeration of symbolic characters. These are gradually developed into statements of mathematical truths, followed by definitions of constants such as π and e. Later, more complex ideas are introduced, including logical statements and algebraic relationships.
Callimahos calls this “inverse cryptography”: not the concealment of meaning, but the deliberate crafting of intelligible, universal structure.
He writes:
“The object of the exercise is getting ideas across to another party, whose thinking processes may be entirely different from our own.”
The symbol set is shown, decoded, and laid out over several pages with deliberate pacing-each segment building on the last. These are not idle constructions; they are, in the analyst’s view, potential templates for real communication.
From Theory to Challenge
By the end of the document, Callimahos proposes testing the reader’s understanding by challenging them to transmit two of the most notorious unsolved problems in mathematics:
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Fermat’s Last Theorem
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Goldbach’s Conjecture
The solutions-encoded in the constructed alien symbolic language-are included on a final page. The invitation is clear: the reader, presumed to be a cryptologist, must prepare to converse across the cosmos.
More pointedly, the analyst warns that intellectual contact may carry consequences. Referencing Russian astronomer Iosif Shklovsky, he identifies five potential fatal crises for any civilization-ranging from self-destruction to cognitive overspecialization.
The Cryptologist’s Burden
“If ‘they’ but know the seventh digit of the ‘fine structure constant,’ they are ages ahead of us.”
With this line, Callimahos collapses the gap between mathematics and strategy, between alien communication and national security.
The cryptologist, he writes, must not get excited.
He must instead prepare to decode what could be the most consequential message in human history.
This isn’t science fiction. It’s an operational framework.
And it was published-unclassified-by the CIA.