In 2015, around the time the survey was winding down, Wright heard about a peculiar object that another astronomer, Tabetha Boyajian, was investigating. The object, which came to be known as Tabby’s Star, had been discovered using the exoplanet-hunting Kepler space telescope; it appeared to be surrounded by a swarm of material that caused its light to dim at irregular intervals—another possible Dyson sphere. Wright was among several astronomers interviewed for an article about Tabby’s Star, in The Atlantic. “Aliens should always be the very last hypothesis you consider,” he said, “but this looked like something you would expect an alien civilization to build.” The media coverage caused a sensation: Tabby’s Star became the subject of jokes on “Saturday Night Live” and “The Late Show with Stephen Colbert.” With Boyajian and another astronomer, Andrew Siemion, as co-investigators, Wright led an effort to scan the star for radio signals. The search found nothing there, either. (The entity’s flickering is now believed to stem from clouds of dust or a swarm of surrounding comets.)
One natural objection to the search for Dyson spheres is that it presupposes an endlessly consumptive technological teleology. To imagine that alien societies would construct such structures seems to assume that energy collection is those societies’ most important goal. Why couldn’t an intelligent civilization strive to use less energy, not more? Focussing on the sun may be similarly short-sighted; perhaps extraterrestrial power plants tap into some spectacular aspect of reality we have yet to discover.
“Energy use is the observable manifestation of technology, so it’s a very useful parameter,” Wright explained, leaning back in his chair and smiling. “My analogy is the sizes of mammals or plants. There’s no natural evolutionary tendency for all things to get bigger. Nonetheless, we have giraffes and sequoias and blue whales. Some of them are large, and those are the ones we will find.”
In April, 2018, a draft of a nasa appropriations bill appeared in the House of Representatives containing an unexpected provision: it mandated that the agency spend ten million dollars over the next two years to “search for technosignatures, such as radio transmissions.” The paragraph had been inserted by Lamar Smith, the Republican congressman who, from 2013 until earlier this year, chaired the House Science Committee. Smith, who is notorious among scientists for his climate denialism, has long been a fervent supporter of astronomical research. In 2017, he announced that he planned to retire; researchers at the seti Institute considered the language to be a parting gift. To figure out how the money might best be spent, nasa, which had no extant seti program, convened a conference of experts in Houston. Wright co-edited its final report, to which he wrote the introduction.
Michael New, nasa’s deputy associate administrator for research—he is in charge of insuring the quality of the agency’s scientific portfolio—joined the researchers at the conference. He had been struck, he told them, that the term “technosignatures,” which had been used by Smith and others, hadn’t set off “antibodies” at the agency. The word, coined by the seti pioneer Jill Tarter in 2006, is based on the term biosignatures, which refers to evidence—liquid water, atmospheric oxygen—that hints at the existence of living organisms on a planet’s surface. Technosignatures, by extension, suggest the presence of tool use or technology. An electromagnetic message, an artificial megastructure, or an alien monolith would be a technosignature. So would the low-tech damming of a planet’s waterways by a beaver-like species, if it could produce a measurable change detectable from far away. By artfully removing extraterrestrials, their communicative motives, and even their intelligence from the equation, the term makes seti more flexible.
The ten million dollars set aside for seti disappeared during the budgeting process. Still, the mere possibility of money had an effect. Since seti had lost its appropriation, in the early nineties, proposals related to it had rarely been entertained by nasa, and only a small number had been funded. This year, though, the agency offered to hear “observational, theoretical, and archival proposals focused upon the detection of technosignatures,” as part of its Exoplanet Research Program.
American astronomy is a highly organized discipline, with a structured approach to funding. Around every ten years, in a process known as the Astronomy and Astrophysics Decadal Survey, astronomers write papers arguing for new telescopes or robotic missions; they submit their papers to the National Academy of Sciences, where they are reviewed by committees in specialized subfields and then passed on to a central commission of luminaries that, in turn, tells nasa and the National Science Foundation what it should fund. “Astro2010,” the last Decadal Survey report, was two hundred and ninety pages long and made no substantive mention of seti. Only a single paper promoting the field, written by Tarter, appeared during the lead-up to it. Earlier this year, Wright and his collaborators—including the planetary scientist Jean-Luc Margot, the astrobiologists Julia DeMarines and Jacob Haqq-Misra, and the computational social scientist Anamaria Berea—submitted nine papers on a wide variety of seti topics. Wright was lead author on four of them. One, which argued that seti needed a trained workforce capable of attacking the problem from all sides, was co-signed by a hundred and twenty-six astrophysicists.
“If the [Decadal] tells nasa, ‘This is something you should fund,’ then nasa has to fund it,” Wright told me. Such resources would be transformative. “If you don’t have federal money to support students, you don’t formalize the knowledge. You don’t have a curriculum,” he said. Right now, “everyone that works on [seti] is a hobbyist.”
Neither governmental backing nor scholarly approval, of course, can change seti’s incalculably small odds of success. The conceptual limitations that have dogged it in the past may be an insurmountable product of the fact that we are the particular species we happen to be. Linda Billings, a communications researcher specializing in the rhetoric employed by scientists and proponents of space exploration, worked as a consultant on seti-related projects for NASA from 1988 to 1992. In her view, they have often been reluctant to address the fundamental question of whether human technology is likely to bear a resemblance to technology developed elsewhere. A seti skeptic, Billings told me that “the scientific rationale the seti community offers is not sound—it depends on a growing pile of assumptions.” Kathryn Denning, an anthropologist at York University, in Toronto, who studies the social and ethical aspects of space, is similarly doubtful about whether human researchers can anticipate how aliens would use technology. Still, she said, “I think the more nuanced thinkers on the seti front are leaving behind the question of alien motivations and alien sociology as much as they can, and just thinking in terms of astrophysical signatures and the capabilities of their instruments.” She told me that seti has stimulated new developments in astronomy and instrumentation. And many people argue that the extraordinary significance of an actual detection might make the modest amounts set aside for seti seem reasonable, despite the inherent uncertainty of the research. (The ten-year, hundred-million-dollar allocation that was considered in the early nineties equates to roughly four cents per person per year.)
On a sunny afternoon a few weeks after the seti Institute’s awards ceremony, I met Wright on the Caltech campus, in Pasadena. He was attending a technosignatures workshop, which included experts in machine learning, sociology, dolphin communication, planetary science, and astrophysics. It was the meeting’s final day, and the attendees were dividing up the work of writing its final report, claiming sections (“Recognizing and Minimizing Human Biases”; “Lessons from Computational Biology”; “Probes and Relics in the Solar System”) for themselves. Earlier, they had pored over a textbook of ancient, untranslated human languages.
On a bench outside the ultramodern Keck Institute for Space Studies, Wright told me about his favorite sci-fi television show (the space opera “Babylon 5”) and the novels of Arthur C. Clarke (“His aliens are really alien”). He walked me through his plans for a new seti center at Penn State, for which he’d secured three and a half million dollars in pledged funding. The center, Wright hopes, will be an academic home for the discipline, removed from the whims of the federal budget and private philanthropists, where students can be trained in the latest research. To date, he said, only seven doctoral candidates had ever completed a Ph.D. in seti subjects. Now at least five more astronomers—from Berkeley, U.C.L.A., U.C. San Diego, and Penn State—are scheduled to receive one.
In his book “Cosmos,” from 1980, the astronomer and science popularizer Carl Sagan offered a spiritual vision of contact with extraterrestrials. An epistle from space, written by an older and wiser society, could be detected by our radio telescopes; the aliens might then invite us to join a galactic federation of enlightened peers who communicate in a universal tongue. Sagan thought that translating such a message would be straightforward: “We will share scientific and mathematical insights with any other civilization,” he predicted. Wright, by contrast, wonders if humanity’s mathematical practices, such as our attachment to prime numbers, might prove to be idiosyncratic. The Caltech workshop had often focussed on these sorts of “anthropic” assumptions. No one knows whether, if aliens exist, it will be possible to cross the conceptual gulfs dividing our minds from theirs. The universe may turn out to be more creative than our fantasies. Or it may be, as Wright hopes, that a more structured process of imagination can be a means of transcending our limited ideas.
“We’re looking for technology like our own, and so we presume the engineers of that technology will share our principles,” he said. “We’re looking for kindred spirits that will find interesting what we’ve found interesting.” Contemplating this problem, he regarded the Caltech campus from beneath the shade of a tree.