We live, undeniably, in an era of catastrophe. The planet is growing hotter by the year; species are disappearing at unprecedented rates. The impact of our human lives is now so deeply scored into the surface of the Earth that some scientists argue that we’ve fundamentally altered the geological record—what we call the Anthropocene.
Every epoch needs a beginning. Which year best marks the start of the Anthropocene is the subject of ongoing geological inquiry, but the current leading contender is 1950—a nice round number that approximates the beginning of the nuclear era. A few years earlier, atomic weapons tests sent a flurry of radionuclides settling onto the ground—a clear marker of our species’ outsized presence on the planet.
That summer, officials gathered in Los Alamos, New Mexico, for the latest atomic detonation. One day, a handful of scientists walked together to the mess hall for lunch. By the random chance of casual conversation, here the nuclear story intersects with another modern scientific pursuit: the search for extraterrestrial intelligence. A UFO had purportedly been spotted, which had made the news, and the scientists began to joke about flying saucers and little green men. Eventually, the conversation turned into a rapid-fire, playful debate: Was there anything that could travel faster than light?
The men sat down to eat. The conversation drifted. Then one of the scientists—a physicist named Enrico Fermi, who has been described as an “archetypal genius”—posed a question: “But where is everybody?”
His fellow physicists understood the question at once. The universe is vast and ancient; mathematically, life must exist out there. Yet no little green men had ever arrived. Indeed, they’d failed to even call. In the years since that Los Alamos lunch, this contradiction has become known as Fermi’s Paradox. The lack of contact has earned its own name, too: the Great Silence.
The first attempt to listen for Earth’s interstellar neighbors came in 1899, in an era when it was widely presumed that our solar system must be inhabited by other beings. The famed engineer Nikola Tesla realized that a radio might be able to capture messages sent from Mars. Tesla’s radio, set atop Pike’s Peak, in central Colorado, caught a set of faint pulses that he interpreted, mistakenly, as code. Over the next few decades, radio technology advanced until radio telescopes could peer far beyond the solar system. In 1960 an astrophysicist named Frank Drake picked up Tesla’s old mission. He pointed a satellite dish in West Virginia toward Tau Ceti, a star so far away that its light takes twelve years to reach our atmosphere. After a half hour of catching nothing but the noise of local radio signals and vague interstellar hissing, Drake turned his attention to another star. Then another, and another, with no promising results.
With his misinterpreted pulses, Tesla came as close as anyone to finding life beyond Earth. But in the years since, this search for extraterrestrial intelligence has been formalized into an acronym and given a locus—the SETI Institute, a nonprofit that was founded in 1984 and now oversees the only instruments on Earth designed to search for interstellar civilizations. Housed at the institute’s Hat Creek Radio Observatory—which is tucked into a quiet mountain valley in Northern California, a four-hour drive from San Francisco and forty miles from the nearest incorporated community—these satellites have been scanning the skies since 2007, picking up the many crackling noises of the universe, but no clear sign of life.
The observatory is open to the public on Thursday and Friday mornings, though one shouldn’t expect a slick museum-style visitors’ center, or even much in the way of amenities. A sign posted at the end of a long driveway requests cell phones be powered down so as not to interfere with the search. A few small billboards that explain the design of the satellites and a timeline of the project are scattered across the grounds. Inside the observatory’s headquarters—stucco exterior, office park drab—an old television plays a fuzzy documentary that recounts the institute’s history; a collection of posters provides more details on the science. A few researchers sit hunkered beyond the glass of a long window, amid vast walls of circuitry.
The day I visited, tucked just beyond the doorway, in the corner of the lobby, was a wooden post topped with a wooden box that holds, among other objects, a pencil, a domino, a small lump of coal, a few inches of barbed wire, and a Covid test. The collection has been curated by the philosopher Jonathon Keats, an artist-in-residence at the institute who, given the meaningless hiss of static that pours into the satellites here, and given the rather discouraging state of the world these days, sees in these objects a way to help our species avoid extinction.
welcome to the library of the great silence, a placard on the post reads, a terrestrial center for interstellar research on planetary futures.
Jonathon Keats cannot remember when he first learned about Fermi’s Paradox, but it’s a concept that fits the scale of his inquisitive career. Keats is an experimental philosopher and a conceptual artist who has written books that range from fabulist fiction to a biography of Buckminster Fuller. His work aims to strip away the intimidating formalism of academic philosophy so that everyone can engage in deep inquiry about life’s big questions. He sees humor as a tool, though to a skeptic his projects can sound like trippy jokes. In his first public work, Keats sat in a chair in a gallery for twenty-four hours and sold his resulting thoughts. The price depended on the buyer: They had to pay him a single minute’s proportion of their annual salary. In another early project, Keats copyrighted his mind, claiming its shape was, in essence, a sculpture he’d produced.
Keats looked to the cosmos, too, for inspiration. In 2003, the Arecibo Observatory in Puerto Rico received an unusual signal, one that some observers supposed might have an intelligent source. “It was dismissed, ultimately, because it didn’t seem to be sufficiently scientific or mathematical in terms of what was being sent,” Keats says. He found this logic questionable. Why would aliens send something so drab as a textbook? “They’re probably saying something that’s really profound and universal—which would be art.” So Keats developed several different algorithms that assigned colors and shapes to the transmissions’ wavelengths and amplitudes. Passed through these algorithms, the signals were converted into canvasses of colored circles that resembled abstract art.
Lately, Keats’s work has become, if no less speculative, then more somber and staid, focused on the crises we face as a species. He’s working with the Desert Laboratory at the University of Arizona to find ways to preserve culinary traditions in regions that will be ravaged by climate change; with the nonprofit Earth Law Center, he’s developed earnest proposals for how we might incorporate the desires of other species into democratic governance. Fermi’s Paradox offers a shorthand for why such work is needed: The Great Silence can be interpreted as a confirmation of our coming doom.
When Fermi first posed his question, the physicist offered a series of off-the-cuff estimates, defending his sense that we should have heard from extraterrestrial beings. There were a finite set of variables to consider: How many planets in this galaxy can support life? How often does life appear on these planets? How long does it take for life to develop “high technology”? Frank Drake later formalized these questions into an algebraic formula for n, the total number of alien civilizations in this galaxy with whom humans might make contact. The last variable in Drake’s list is codified as l: how long the average civilization with the ability to communicate beyond its planet might persist. Fermi considered apocalypse among the likelier answers to the conundrum—that before anyone built technology capable of crossing galaxies, there was a good chance they’d wipe themselves out. This makes sense, given his task there in Los Alamos. The kind of society powerful enough to reach the stars is the kind of society powerful enough to bomb its own planet into oblivion.
The Great Silence, and this dark implication in particular, came to Keats’s mind in 2020, during an artist residency in the Italian village of Fontecchio. Keats was offered studio space in a deconsecrated Catholic church set amid a region that had been rocked a decade earlier by an earthquake. The seismic violence exposed the older architecture beneath the Catholic ornamentation: This same site had once been a temple dedicated to Jupiter, king of the Roman gods.
Keats spent days sweeping out the dust, contemplating the space. “The church captured my imagination as an unintentional monument to societal transition,” he later wrote in an essay. Here, “a thousand-year succession of cultures and belief systems had been accidentally preserved in the architecture, now exposed all at once by the ravages of time. If I were asked by visitors from another planet to recommend places that reveal facets of human nature, I might guide them to this site.”
With those visitors in mind, Keats asked locals to contribute objects that reflected moments of transition for civilizations here on Earth. Many were collected out of the quake-shattered ruins of Fontecchio. Keats assembled the collection and displayed it inside the church: Thus the first branch of Keats’s Library of the Great Silence took shape.
If l, the average lifespan of intelligent civilizations, is somewhere close to zero, that implies the existence of a bottleneck—some “Great Filter” that snuffs out progress before any given lifeform can sing out to the stars. Maybe the filter is the rareness of the spark that imbues inert matter with life—which, so far as we know, has only happened once, here on Earth. Or the filter may be one of the many unlikely feats that preceded the emergence of intelligence on this planet. Our species’ success depended on the development of photosynthesis, of nucleated cells, of multicellular lifeforms; we’ve benefitted, more recently, from the emergence of language and tools. The fact that our earthly predecessors leaped past each of these hurdles may just be a long run of blind luck, an accomplishment unmatched anywhere else in the universe.
That’s the rosy version, at any rate. The darker possibility is that the Great Filter lies not behind us, but looms ahead, in the form of some event that ends our species’ technological advance. This grim likelihood is the impetus for Keats’s library, though he intends the project as a hopeful countermove. If we face the chance that civilizations across the universe “might do themselves in more often than not,” as Keats put it to me, then we might be able to contemplate the possible causes of our own demise, and thereby avert them.
This project retains some of Keats’s old whimsicality. He launched the library determinedly asserting that the collection was meant not just for humans, but for other forms of interstellar life as well. That conceit led Keats to Hat Creek, a site where, he says, “we have shown the greatest curiosity toward beings elsewhere in the universe.” It’s a potential tourist destination for aliens, a place they would be likely to seek out.
Keats also had to consider an inherent challenge: “Most of the occasions for the troubles of the world are grammatical,” he likes to say, quoting Montaigne—and if our grammar gets tangled as we translate between human languages, what might happen in our attempt to speak to beings from other worlds? When NASA launched its Golden Record into space in 1977, the agency worked around this problem by including greetings in a wide variety of languages, alongside music and images. Keats came up with a different approach: He decided to jettison language entirely. Instead, he embraced the logic of mathematics, and the Venn diagram in particular.
Inside the box that holds the Hat Creek collection, a raised strip of wood delineates several interlocking chambers. By arranging the objects within the chambers, visitors—human or otherwise—are meant to consider their connections and relationships. After he settled on this approach, Keats decided that even if he dropped the conceit—if he stopped considering little green men altogether—he’d nonetheless found a fruitful method. There is power in abandoning language and contemplating the artifacts of our past in and of themselves, he says.
When Keats announced the opening of the library in the spring of 2022, I was already thinking about apocalypse. How could I not? A global pandemic was finally waning, but a heat wave was rising to take its place. The US government was still sorting out its response to a violent insurrection; the Supreme Court was overturning decades of jurisprudence. Something seemed to be approaching an ending—to this American experiment, at the very least. So I was drawn by the idea of seeking some kind of answer.
I arrived in Hat Creek late on a Thursday morning in July. I stood alone in the heat, reading the posters. Then I stepped inside the stucco building and opened Keats’s glass box. To begin my own small bout of research into planetary futures, I selected two objects at random and placed them within the chambers: a lump of coal and a battery. Energy, I thought. Then I thought about how this was a rather lame thought.
Next I picked up a tin of anchovies and a bone-shaped plastic dog toy, two objects that seemed divergent enough to force me into some kind of clarity. And—well, both had something to do with animals? My next thought seemed more promising: the fact that canning was a life-extending development, while molding plastic into the shape of a bone was, on its face, rather pointless. Does the dog care? Here was form over function, and form for the sake of a consumer being sold a domesticated approximation of a pet’s feral habits. Strange world.
Did this epiphany have any practical merit? I doubted it. After my long drive, I was underwhelmed and exhausted. Perhaps I had failed to shake off the constraints of language. Perhaps I should’ve taken some kind of mind-altering substance to get warmed up. I felt far from any insight that could steer the human race away from doom.
The inevitable downfall of civilization is not the only way to explain the Great Silence. Some astronomers believe we just haven’t looked far enough. The small sliver of the universe that our telescopes and satellites have scanned these past sixty years is the equivalent of one swimming pool of water within the world’s oceans, as one academic paper notes. If you find no dolphins in that pool, do you conclude that dolphins don’t exist?
Other explanations for the silence are more whimsical, not unlike the beginnings of the sci-fi epics I loved to read as a child: Perhaps our solar system has been quarantined for our own good, as some researchers suggest, so that we can develop into true social maturity without outside influence. (“It might turn out that the Great Silence is like that of a child’s nursery,” as one scientist wrote in the Royal Astronomical Society’s quarterly journal, “wherein adults speak softly, lest they disturb the infant’s extravagant and colourful time of dreaming.”) Or perhaps we’ve been deemed a danger, and no one else wants us to know of their existence. The so-called “zoo hypothesis,” meanwhile, offers a middle road: This planet could be an interstellar zoo, with aliens watching from afar and wondering what these zany creatures will do next. My drive north from San Francisco had included a long haul through the Central Valley, a once-fecund wetland whose wildlife had been wiped away in favor of industrial farms, and then a climb up into fire-scarred hills—a living diorama of self-destructive behavior.
As it turns out, most of the staff at Hat Creek during my visit were summer interns, some fresh out of high school. It didn’t seem like the Library of the Great Silence had been a central piece of their intellectual experience. They’d hardly considered it at all. One of the interns told me he’d been bewildered at first by the Venn diagram, then decided the whole project was funny. When I explained what had brought me to Hat Creek, the student seemed confused. “Why would a certain technological level cause our society to collapse?” he asked.
Alex Pollak, the lab’s operations director, told me he sees the library as a curiosity, something that can allow visitors to start considering the kinds of deep questions that underlie SETI research. When I asked about the silence, Pollak suggested it might be a matter of technological advancement. In the 1960s, human radio signals were far louder than they are today. “Our amplifiers, our receivers were so insensitive,” he said, “so you needed a lot of power.” Now, with more precise receivers, our radio signals have grown quieter. If anything is watching from out there, tuned in to their own radios, it’s as if we’re dwindling into nothingness, despite our ever-intensifying presence on this rock. Eventually, Pollak noted, our communication may shift away from radio signals entirely, to lasers and fiber-optic cables, erasing our presence from any distant radio search.
If Pollak’s team successfully finds alien intelligence, the discovery itself would be a transformation—arguably the greatest in human history. When I asked what he thought might happen if the search succeeded, Pollak wasn’t sure that most people here in the United States would believe it. Here he revealed that he, like Keats, is concerned with the state of human societies. When the internet first emerged, he explained, it was seen as a hopeful technology, one that might drive civilization toward a utopian future; now, it’s given us digital echo chambers that tend to ignore and distort the urgent truths of science. Far more breakthroughs will be necessary before our species can travel beyond our solar system, “so there is still a lot to come,” he said. “I hope we will survive our technology. But, time will tell.”
There is nothing particularly novel about believing you live in the end times. Christ preached that some great change would swallow the world within a generation of his birth. Despite the planet’s persistence, doomsday predictions have recurred throughout the millennia—and, according to several scholars, have reached a blaring crescendo in our modern world. Perhaps this is just a result of an onslaught of information. “Only a catastrophe gets our attention,” says Alfonse Stompanato, the professor of popular culture in Don DeLillo’s White Noise. “We want them, we need them, we depend on them.”
Literary critic Frank Kermode offered another explanation for these consistent dreams of apocalypse: The sense that an ending is looming gives order to otherwise inscrutable lives. We’re born into the middle of things, plopped into a world that’s already rushing forward and continues to rush even as our cognizance dims. To believe that the world will soon change completely and irrevocably is to take this messy blur of time and force it into a clearer shape. But a corollary conclusion is that an obsession with apocalypse is really just a form of narcissism. To be alive amid the crumbling of civilization makes one a player in history’s most important chapter. It can all make the apocalypse seem alluring; as the writer Geoff Dyer points out, zombie movies feature a certain idyllic quality—at least before the zombies appear—conjuring a world free of traffic jams and grocery-store lines. What is the apocalypse but a larger version of what I was after on my trip to Hat Creek—a chance to sit amid the stillness, finally free of life’s great crush?
As technology has progressed, it’s become possible to search not just for radio signals, but for atmospheric changes on distant planets—subtler hints of the presence of life. Here on Earth, for example, until microbes developed the skill of photosynthesis, there was virtually no oxygen in the skies. By identifying such “biosignatures,” astrophysicists can expand their search, looking not just for intelligent life, but any form of life at all. If scientists do confirm the presence of microbial life on another planet, I’d like to believe it would be a joyful occasion—an expansion of the boundaries of wondrousness. Space would no longer be a vast void, sterile and empty. Unfortunately, given the logic of the Great Filter, the presence of alien microbes would be a terrifying fact.
Most scientists presume that life has emerged either only once, just here on Earth, or many times over. (Twice is a statistically improbable frequency.) One microbe on Mars, then, suggests the cosmos must be smeared in life; and the fact that none of this life has evolved into a star-traveling society would imply that the Great Filter is not life’s emergence, but some later challenge. The more complex the life we find, the worse the news becomes: It sets an ever-later date for the filter. The presence of a multicellular being would prove that it’s not so hard to become multicellular. Beings that communicate like animals would prove that communication, too, is rather easily achieved. Each step of advancement makes it likelier that everywhere across the universe, many creatures have advanced that far—but no further. “I hope that our Mars probes discover nothing,” the philosopher Nick Bostrom wrote in an essay. “Dead rocks and lifeless sands would lift my spirit.”
It’s far preferable to find some distant society that’s advanced beyond our level. Lately, scientists have found a shortcut for this search—an extension of the idea of biosignatures, analyzing alien atmospheres not just for signs of life but for signs of technology. Earth offers analogs: chlorofluorocarbons are industrial byproducts that became infamous in the 1980s after it was discovered that they were ripping holes in the ozone layer. If other planets feature chlorofluorocarbons, these should be perceptible by the James Webb Telescope, which began sending back imagery last year. One recent paper pointed out that a planet running an industrial system of agriculture in the human style, expanded to feed a population of 30 billion, would so thoroughly change the amount of nitrogen in the atmosphere that its abundance, too, would be observable with the right technology.
This new consideration of “technosignatures” marks a leap forward for SETI; after years of neglect, NASA recently began funding research in this sub-field. As scientists have developed the technique, they’ve inevitably pondered the reverse search: If aliens are seeking us, what would they see? Our own technosignatures would be just faintly visible to distant observers using their own version of the Webb Telescope. It’s a rather gloomy prospect that as we search for interstellar intelligence, what we most want to see are places even more tarnished than Earth.
After Pollak and I finished talking, I noticed that a shelf in the lobby contained a row of toys, a collection of famous aliens: Yoda and E.T.; Marvin the Martian of Looney Tunes fame, his black face contained within his Roman helmet. These, it struck me, were another form of library, an archive of our attempts to imagine life beyond these stars. The wildest dream of a creature on the shelf was Star Wars’ Jabba the Hutt, a portly worm with a human face. The rest were closer cousins, four-limbed and upright, distinguishable as inhuman only by their small bodies or their pallid, hairless skin.
The notion of a Great Filter implies that there is a hierarchy: Intelligence, in whatever form, is desirable. Thus human beings—not yet able to cross the cosmos, maybe, but able at least to dream that we will—are considered the most advanced of the species sharing this planet. We are, in this view, the best model for what we’re seeking. Indigenous thinkers have critiqued this as a narrow way of imagining things. “Where do you acknowledge that no society is wholly intelligent or that there is no objective way to judge that one society is more ‘advanced’ than another?” a group of scholars, including several Indigenous scholars, wrote in an open letter addressed to SETI researchers. “How will you determine who is living versus what is not? Can you recognize that on that one simple issue, ‘Who is alive?’ Indigenous people on this planet generally (though not completely) disagree with object-oriented scientists?”
The Indigenous experience is instructive in other ways, too. In 1992, the five-hundredth year after Christopher Columbus stumbled onto a Caribbean island, replicas of his three ships sailed just beyond Cape Canaveral, Florida, as a backdrop for the space shuttle Endeavor’s launch on its maiden voyage. Later that year, on Columbus Day, NASA embarked on its first SETI project. The federal government seemed to miss the ugliness of this metaphor. So much disease and violence followed in the wake of Columbus’s arrival that “we’ve already survived an apocalypse,” as the Ohkay Owingeh Pueblo writer Rebecca Roanhorse told the New York Times in 2020. If this is the model for our search through the skies, some scholars wonder if our attempts to contact distant civilizations are even morally defensible.
This leads to one more answer to Fermi’s Paradox—a way for l to be short without it meaning that intelligence is self-defeating. Perhaps the civilizations that survive are those that never bother to reach beyond their skies. This has become known as the “sustainability solution” to Fermi’s Paradox. Consider it an implicit warning. There are plenty of examples on Earth of societies that grew so fast they wiped themselves out. If we haven’t heard from aliens, perhaps it is because this is the kind of growth trajectory that kills you. To survive on Earth, we might have to pay more attention to living here, rather than seeking to expand and escape.
Visitors to Keats’s library are invited to contribute their own artifacts to it, and it seemed almost negligent to leave Hat Creek without adding something of my own. But I’d forgotten to consider this when I’d packed for my excursion. Besides my clothes and toiletries, all I had was the dirty wrapper from a chicken sandwich and an empty plastic water bottle—fitting artifacts of the Anthropocene, perhaps, but I was reluctant to use the library as a trash can. So I left nothing. I got in my car and drove away.
When I told Keats about my struggle to find meaning at the library, he wasn’t surprised. Over time, he’d realized that, for all its poetic resonance, Hat Creek had serious shortcomings. Keats now thinks engaging with the library shouldn’t be a one-off experience, or something undertaken alone, which makes Hat Creek—so remote that it allows only brief engagement from wanderers like me—a difficult place from which to launch a campaign to save the planet.
To remedy this, he indicated that the library was expanding into new locations. Some will be more narrowly focused: One new branch will contain only fossils, for example, offering an opportunity to contemplate how Earth’s nonhuman species have innovated through the years. He was also hoping to create spaces that were less libraries than laboratories, that included not just Venn diagrams but devices that promoted more elaborate arrangements of the collected objects.
He did his best to explain the idea. He’d been attempting to find a way to encourage more generosity, he said, which he saw as essential to the future of civilization; one obstacle, he’d decided, was the psychological principle of loss aversion, in which the pain of losing something is far more powerful than the pleasure of its gain. So he’d been running various forms of ancient currency through his words-free laboratory, a process that had inspired an evolving concept for a new kind of coin. A built-in optical illusion, for example, might encourage spenders to feel like the money’s value diminished as it was given away. I can’t say that I understood this new coin well enough to explain it, but it clarified that this library was not a clever joke about aliens and not an art project. It was an earnest proposal, born of earnest concern for the world.
Keats told me that if I wanted to experience the true power of this project, I needed to build my own branch of the library and invite people to contribute. He’d send me the templates, he said. But it was hard for me to imagine walking up to my friends and neighbors and asking for their detritus so we could think together about how societies fail.
In a recent presentation for the SETI Institute, Keats noted that this kind of collaboration has been too often absent from other attempts to reach out to alien life. He criticized NASA’s Golden Record, for example, which aimed to tell the story of Earth—it was akin to the “barroom bore,” he said, who only wants to talk about himself. His library, by contrast, was built to facilitate conversation.
But conversation implies the end of the silence, and with it would go the apocalyptic gloom: The presence of fellow survivors somewhere out in the universe would suggest that there is no Great Filter. So the little green men that Keats invited to his library would, upon arrival, render its purpose moot. If there is silence in this library, it is drawn from the fact that amid the endless cosmos, our small little racket remains the only message we’ve got to decode. Perhaps one day we’ll hear a message from the skies that will change our trajectory. For now, though, more important than shipping the story of Earth out into the universe is deciphering its meaning for ourselves.