SETI

SETI is the Search for Extra-terrestrial Intelligence, a research program devoted to detecting signs of civilization beyond Earth. In the novel, it is more than Crowe’s workplace: its long, mostly unanswered search supplies the methods and cautions that shape humanity’s first attempt to communicate with the Yrr. When an intelligent presence is no longer merely hypothetical but appears to be in the ocean, SETI’s central problem changes from where to listen to how to recognize a mind unlike one’s own.

Origins and institutional history

The novel traces SETI’s research to the early 1990s, when NASA funded a targeted search for extraterrestrial life among nearby stars. The launch was timed to coincide with the five-hundredth anniversary of Columbus’s arrival in the New World. At Arecibo Observatory in Puerto Rico, the world’s largest radio telescope began a new observation program. Private sponsorship later enabled other projects around the globe, while Project Phoenix became the best-known of them.

That history places SETI between public scientific infrastructure and private support. NASA’s funding initiated the targeted search described in the novel; subsequent sponsorship helped the work extend beyond one observatory. Arecibo is both a physical center of observation and the source of an important precedent: a message deliberately sent toward a distant stellar destination. SETI’s efforts therefore include listening for signals that might arrive from elsewhere and considering what humanity itself has already transmitted.

The program’s working scale is vast but not unlimited. Phoenix directs its attention to a thousand stars similar to the Sun, each more than three billion years old. Crowe describes the search as constrained by a range of about two hundred light-years. In the mid-1990s, SETI analyzed sixty billion signals and reduced them to thirty-seven that could not be matched to a natural phenomenon. The results did not establish that any of those signals came from an extraterrestrial civilization; their importance lay in remaining unexplained, among a near-unimaginable volume of observations.

Project Phoenix and Crowe

Crowe is introduced to Leon Anawak as a scientist who listens to space for signs that someone else is there. Her plain account of the search begins with a question—whether anybody is out there—and an admission that she has never received an answer. That history makes her neither a triumphant discoverer nor a detached skeptic. She remains committed to the possibility of other civilizations while living with the evidence of silence and uncertainty.

Her comparison with Anawak’s whale research makes the scale of the novel’s later problem visible. Both occupations involve interpreting signals produced by beings whose communications may not be readily intelligible to humans, but SETI’s targets are distant stars, whereas Anawak studies whales he can at least confirm are present. Their exchange establishes a meaningful difference between looking for evidence of life and interpreting the behavior of a known animal. Later, when the Yrr become the object of investigation, neither task is sufficient by itself: existence, communication, and understanding must be treated as separate questions.

Crowe’s expertise is why she is recruited for the Greenland Sea mission. Judith Li identifies the need for someone who spends her time thinking about communication with nonhuman life-forms, and Anawak recommends Crowe as well qualified. By the time Crowe joins the team, SETI’s work at Arecibo has been shut down for lack of funding. The interruption is a sharp reversal: the specialist called on to help make contact has been forced to stop the long-running search that formed her professional life. Yet the methods and questions developed through SETI remain useful in the crisis.

From listening in space to signaling underwater

Crowe argues that the ocean changes the technical problem. Space permits large packets of information to travel as microwaves, without cables; underwater, water absorbs short-wave energy, while long-wave transmission would require enormous antennae. Light can carry information only over comparatively short underwater distances. Sound is the viable medium, but echoes and interference can cause a message to overlap with itself and become unintelligible.

The team’s proposed answer draws on marine mammals. Anawak explains that dolphins use song to overcome the difficulties created by echoes and interference; the team adapts that principle in developing a special modem. SETI’s interstellar expertise does not simply transfer intact to an underwater environment. Instead, the communication plan combines Crowe’s knowledge of prior attempts with a technique modeled on animals already communicating in the medium where the Yrr are believed to live.

The choice of mathematics supplies the message’s proposed common ground. Crowe treats mathematics as a language grounded in the physical laws that any intelligence subject to the same conditions would encounter. Her account recalls SETI’s 1974 transmission toward a globular cluster in the constellation of Hercules. It contained 1,679 characters encoded as binary pulses. Because 1,679 is the product of the two prime numbers 23 and 73, the message’s dimensions could help a recipient infer how to arrange it: 73 columns of 23 characters.

Once arranged as black-and-white blocks, those pulses form an image. The message begins with numbers and the decimal system, then gives atomic numbers for water, carbon, oxygen, nitrogen, and phosphorus. It continues with information about terrestrial biochemistry, including DNA bases, sugars, and the double helix, before depicting the human form in connection with DNA and evolution. A diagram of the solar system and information about Arecibo Observatory complete the transmission. Since human units of measurement would not be self-explanatory to an alien recipient, the wavelength itself is used to indicate average human height.

The signal also illustrates the limits of intention. It was expected to take twenty-six thousand years to reach its destination, making a reply and return journey a fifty-two-thousand-year prospect. Meanwhile, Earth had been sending radio waves into space for decades, including ordinary radio traffic and communications from intelligence agencies. Crowe’s point is that humanity had already made its technological presence detectable; a formal invitation was not required to announce that a technological civilization existed.

A staged test of intelligence

For the underwater exchange, the team adapts SETI’s logic to a much shorter and more urgent encounter. The first message is deliberately straightforward: two mathematical problems. A correct reply could establish that a signal had been received, that its sender existed, and that it could manipulate numbers. Crowe presents this as the beginning of a staged inquiry, not as proof that the sender thinks or experiences the world as humans do.

The stages distinguish detectable presence from dialogue and dialogue from conscious response. First, Crowe wants to determine whether anything is there. Next, the team must establish whether communication is possible. Only after that can it investigate whether the Yrr are responding consciously, rather than displaying intelligence without awareness. Even evidence of consciousness would not show that the Yrr share human values. Crowe warns against assuming that intelligence entails familiar ethics, motives, or concepts of personhood.

That distinction extends SETI’s search beyond signal detection. The program’s speculative concern with machine civilizations—intelligences that might continue developing after their creators had disappeared—helps Crowe challenge the automatic equation of skilled behavior with consciousness. She invokes the example of the chess computer Deep Blue defeating Garry Kasparov in 1997: victory demonstrated a capacity to perform, but did not settle whether the computer was aware of what it had done. Likewise, building cities or laying underwater cables cannot, by itself, answer every question about consciousness. The novel uses SETI’s caution to resist treating either technical ability or unfamiliarity as a complete account of mind.

Contact and the limits of the search

The Yrr eventually answer the team’s mathematical exercises correctly. Murray Shankar presents the results as a perfect score, evidence that the recipient has heard and processed the questions. The answer is not a straightforward translation of the Yrr’s ordinary language: Crowe says the team still cannot make sense of the earlier Scratch signals. Instead, repeated and rearranged numerical answers form a second code. Recognizing that pattern leads Crowe to read the sequence as a black-and-white pixel image, using an approach associated with the image-bearing messages familiar from SETI and the film Contact.

The reply marks an achievement, but not the end of interpretation. The team has evidence of a response and of mathematical competence; it still has to ask what the image means and what kind of awareness produced it. This is the novel’s decisive transformation of SETI’s original question. The search that began by listening for a possible greeting among billions of signals becomes an encounter in which a reply is real, nearby, and still radically difficult to understand. SETI matters not because it guarantees comprehension, but because it offers a disciplined way to separate what has been detected from what remains unknown.