by Bryan Walsh
There’s something of the move-fast-and-break-stuff ethos of Silicon Valley in the METI movement, a willingness to disregard risk if risk gets in the way of potential reward. That might be acceptable if the reward is a new search engine or social network. It is considerably less acceptable when innovation brings with it the possibility, however remote, of a world-ending threat, as we’ve already examined in the cases of biotechnology and artificial intelligence. This is the debate over anthropogenic existential risk, played over again. If an act carries even a minuscule risk of human extinction, shouldn’t we err on the side of safety, given the ultimate stakes at play? And if that’s the case, perhaps we should pause before sending an unknown alien civilization of unknown technological capability and unknown intentions Google Maps directions to our home planet?
Olle Häggström, a mathematician at Chalmers University of Technology in Sweden and the author of the existential risk book Here Be Dragons, thinks so. “There are optimists who say that good things can come out of establishing communications,” Häggström told me. “We could learn wonderful things from them. But an extraterrestrial civilization of very advanced technology might be a threat—and they might want to get rid of us before we become a threat to them. There are real evolutionary-style arguments pointing in that direction. Maybe we’d be better off observing exoplanets for ten or twenty years until we’re in a better position to assess the risk of communication. The risk is too great.”
I personally think Häggström is right. The potential benefits of active messaging don’t outweigh the risks that would come with it. To understand why, we should look at what first contact might actually be like.
There is, Seth Shostak of the SETI Institute assured me, a protocol in place in the event of the discovery of alien life. And contrary to Hollywood, there are no Men in Black ready to spirit away the evidence to Area 51 before it becomes public. SETI itself, like the mother science of astronomy from which it sprang, has a communitarian ethos, one where the contributions of amateurs are welcomed and openness is taken for granted. “There’s no policy of secrecy, because as soon as you find a signal that’s even the least bit interesting, people today would be tweeting it or sending emails to their relatives,” said Shostak. “You’d need to tell people anyway because you’d want someone else at another observatory to verify it. Otherwise you wouldn’t really believe yourself. There are too many things that could go wrong.”
Shostak experienced his own close call on June 24, 1997, when a blip came through from a star called YZ Cet, some 12 light-years away—practically next door by the vast distances of interstellar space.23 That day the SETI Institute was making use of a 140-foot radio telescope in Green Bank, while Shostak was monitoring the work back at the institute’s offices in California. To spend your scientific career searching for intelligent life is to spend much of it in a state of suspended disappointment. Every seeming signal indicating that an alien civilization might be out there has turned out to be a false alarm, often either the misheard background hum of the cosmos or the electronic chatter of humankind’s own satellites. But the search runs on hope, and in the early hours of that morning on June 24, Shostak found himself hoping.
It wasn’t meant to be. Even as Shostak was fielding a call from a curious New York Times reporter and pondering just how SETI might announce to the world that aliens in fact exist, further checking showed that the signal from YZ Cet wasn’t from YZ Cet at all. It turned out to be a telemetry signal from the Solar and Heliospheric Observatory, a joint U.S.-European satellite that studies the sun from space. The transmission had bounced around the radio telescope in West Virginia in a way that temporarily mimicked an alien source. Another null result; another false alarm. “A close call that wasn’t that close,” Shostak told me.
But had that signal been real—and confirmed by another observatory—Shostak would have notified the International Astronomical Union, as well as the United Nations and any other relevant research organizations. The discoverer is supposed to get the right of first public announcement—which would be the press conference to end all press conferences—but the data would be made available to anyone who wants it. (The exception would be the actual coordinates of the signal source, to prevent anyone from simply starting up an interstellar conversation on their own.) Then humanity, or some part of it, would have to decide whether to send a response—and what should be in it. Which would be a very, very interesting debate.
Unless one side of the conversation learns to break the laws of physics and travel faster than light, however, actual communication with a civilization via radio would likely unfold over centuries, if not longer. That’s how vast the distances are between the stars. We’d know that someone, or some thing was out there—but what would that knowledge actually mean to human beings?
Sagan believed that the discovery of extraterrestrial intelligence would be a great unifying force. Instead of seeing ourselves as fractious members of separate nation-states or sects or races, we would come together as shared citizens of this pale blue dot called Earth. “Just the knowledge that we’re not alone would be philosophically profound,” said Jacob Haqq-Misra, a research scientist at the Blue Marble Space Institute of Science and a member of the METI movement. “When people saw the images of Earth from space, it was relevant to inspiring modern environmentalism, to realize our planet isn’t an infinite resource. I like to think the discovery of intelligent life would have a similar effect where now we’re all Earthlings, because we know there’s an other.”
As Kathryn Denning noted, with affection, this cosmic optimism was part of the “pot-smoking hippie side of Sagan.” As an anthropologist, though, Denning is more pessimistic about how humans would handle contact. “Our evidence about humanity is that we’re profoundly xenophobic and really rather nasty,” she said. “We don’t like things that we don’t understand, which is almost a given in any contact scenario. The likelihood that we would have the upper hand is rather small. So I don’t really see how that would bring out the best in anybody.”
This is what makes the existence of aliens—and therefore attempts to actively contact them—an existential risk. Humans and aliens are likely to be separated not merely by gulfs of space but of time as well. If extraterrestrial civilizations have rates of development anything like human beings—meaning rapid technological growth following industrialization—a head start for the aliens of just a century could be enough to create a massive military gap, akin to the difference between a World War I–era army and the modern U.S. military. We Homo sapiens only developed the ability to send and receive space signals, and therefore be capable of making contact, less than a hundred years ago, but the universe has existed for about 140 million times longer. As the writer Steven Johnson pointed out in a 2017 story for the New York Times Magazine, “The odds that our message would reach a society that had been tinkering with radio for a shorter, or even similar period of time would be staggeringly long. Imagine another planet that deviates from our timetable by just a tenth of 1 percent: If they are more advanced than us, then they will have been using radio (and successor technologies) for 14 million years.”24
The chances of us making contact with an alien species technologically on par with us are incredibly small, less likely than randomly running into a high school acquaintance in a foreign airport. Since any alien civilization less advanced than human beings probably wouldn’t yet be capable of sending or receiving signals, it’s much more likely that our alien pen pals would have outpaced us. That would be doubly so if the extraterrestrials could somehow traverse interstellar space and visit us in person, a feat that is unimaginably beyond human capability.
In a 1979 book called Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, the author Robert Freitas created a scale that measured the imagined power differentials between alien societies and human beings. To Freitas, humanity in all its accomplishments compared to a species that could cross i
nterstellar space might be no more than a single amoeba against the entire United States. “Not only would such a civilization seem godlike to us,” Freitas wrote, “it would actually be God for any practical purpose that can be imagined.”25
Humans have some experience with what happens when two geographically separated civilizations at differing levels of technological development encounter each other. It is the European invasion of the Western Hemisphere, and it did not go well for the people who were already living here. Recent research estimates that the indigenous population of the Americas in the years before Columbus reached Hispaniola was as high as 60.5 million.26 Thanks largely to the infectious diseases imported by Europeans—diseases to which the indigenous peoples had no immunity—as well as the invaders’ policies of exploitation, enslavement, and massacre, the population of the Americas was reduced by 90 percent in just a century. Civilizations like the Aztecs and the Incas were utterly destroyed. The scale of death was so extreme that tens of millions of hectares of now-untended farms were reclaimed by forests, which in turn sucked so much carbon dioxide from the air that global temperatures actually fell.27 The legacy of the Americas’ first contact with Europeans is one of slaughter, genocide, and cultural extirpation. And that may well be our fate in the event of alien arrival.
In 2015 a number of science and tech luminaries—including Elon Musk, who seems to view aliens with the same instinctive wariness that he does AI—signed a statement opposing METI efforts, unless there was extensive discussion first.28 And no less an academic star than Jared Diamond—whose landmark book Guns, Germs, and Steel argued that geographical differences explained the fatal technological and biological gap between conquering Eurasian civilizations and indigenous Americans—has warned that it would be “suicidal folly” to try to contact aliens. “If there really are any radio civilizations within listening distance of us then for heaven’s sake let’s turn off our own transmitters and try to escape detection, or we are doomed,” Diamond wrote in his 1992 book, The Third Chimpanzee.29
Surely, though, there’s some kind of military plan to handle an alien invasion, one that might bring all of humanity together, finally fighting on the same side? President Ronald Reagan told an audience of high school students in Maryland in 1985 that the arrival of hostile aliens might broker peace between the United States and the Soviet Union. “If suddenly there was a threat to this world from some other species from another planet outside in the universe,” he said, “we’d forget all the little local differences that we have between our countries and we would find out once and for all that we really are all human beings here on Earth together.”30
If there was a threat to this world from an alien species, however, chances are the only thing we’d do together is die. Give the Russians some credit for honesty on this score. In a 2013 press conference at Russia’s Titov Main Test and Space Systems Control Centre, a journalist asked Sergey Berezhnoy, the center’s deputy chief, whether the Russian military could protect the country from an extraterrestrial invasion. “So far, we are not capable of that,” said Berezhnoy. “We are unfortunately not ready to fight extraterrestrial civilizations.”31
The Pentagon appears no more prepared. The U.S. Air Force had a postwar program to study unidentified flying objects (UFOs), called Project Blue Book, but the military terminated it in 1969 after concluding that the alleged UFOs presented no national security threat, represented no technological development beyond current knowledge, and almost certainly weren’t extraterrestrial in origin anyway.32 More recently, the New York Times revealed in 2017 that the Defense Department had spent $22 million on the semi-secret Advanced Aerospace Threat Identification Program, which investigated reports of UFOs.33 The program had been shut down in 2012, and it’s still not clear whether its existence had more to do with a genuine concern about the threat posed by aliens, or former Senate majority leader Harry Reid’s personal interest in the subject.34 (Reid represented Nevada, which after all is home to the mythic Area 51.)35 In 2018 President Trump proposed creating a new branch of the U.S. military called the Space Force, but its responsibilities would have more to do with using outer space to fight wars on Earth, not defending the planet from extraterrestrial invaders—assuming Trump’s vague notion ever becomes a reality.
Even if the military can’t save us, is it possible that Earth itself would offer some kind of home-field advantage against encroaching aliens? In Wells’s The War of the Worlds, the invading Martians are so advanced that they possess “minds that are to our minds as ours are to the beasts that perish,” and were armed with heat rays and chemical weapons.36 Humanity wins the war only because the aliens succumb to Earth diseases against which they have no immunity. But in real life there’s no reason to expect that we’d be saved by patriotic germs. As happened in the European invasion of the Americas, it’s often the more technologically advanced invaders who carry killer diseases, not the other way around. Smallpox, measles, typhus, and cholera were Europe’s fatal gifts to the Americas, and were primarily responsible for the ethnic cleansing of the New World.37
Worrying about germs assumes that any arriving aliens would be biological, just like us. But that assumption might be nothing more than organic chauvinism. As we saw in the last chapter, there is at least the possibility that we human beings could eventually develop artificial general intelligence, and that such AI could become superintelligent, displacing us as the dominant power on the planet. If an alien civilization had centuries or longer to develop than we’ve had, that would give them even more time to create AI of their own—and for that AI to take over and begin looking to expand to the stars. If nothing else, AI aliens would complicate any attempts at communication. Not only would we need to try to talk to an alien species that had evolved on a separate planet light-years away, with little shared frame of reference, but it might be a species that had already shed its organic roots. If it’s difficult enough to imagine what superintelligent AI developed by human beings might be like, just try to conceive of alien AI.
An extraterrestrial intelligence that is artificial might be more likely to actually reach our planet, since it presumably wouldn’t be held back by finite biological life spans. Even if aliens were organic, they might well prefer to send robot probes to colonize the galaxy, for the same reason that all of humanity’s exploration of the solar system, save our nearby moon, has been done by machines, not astronauts.
Our greatest defense against a hostile extraterrestrial intelligence, whether organic or artificial, is interstellar distance. But aliens could wreak havoc on us simply by sending a signal, without ever visiting Earth. Unless aliens shout “Hi!” over the cosmic loudspeakers, a message from space transmitted by radio would almost certainly need computer analysis, which brings with it a threat any computer user should be aware of: malware. Computers have antivirus software, but in a 2018 paper, Michael Hippke of the Sonneberg Observatory in Germany and John Learned of the University of Hawaii note that there would be no way to be certain that we could decontaminate an alien message before we opened it. Such a message could well contain a virus that might disable global technology—or something even worse. Opening this message would therefore constitute an existential risk in itself—after all, as Hippke and Learned write, “it is cheaper for [aliens] to send a malicious message to eradicate humans compared to sending battleships.”38
For our species to meet its doom because of poor email hygiene would be tragic and yet somehow fitting, at least if you’ve ever been part of an email reply-all-pocalypse. But there would be one positive takeaway from contact with extraterrestrial intelligence, whatever happens next. We would know that at least one independently evolved intelligence had managed to survive all the existential threats that the universe could throw at it—asteroids, gamma rays, abrupt climate change—and all that it could do to itself. It would provide a measure of existential hope to balance out the existential risk that suffuses life on Earth in the early twenty-first century.
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ut what if it turns out that there isn’t anyone out there, that we really are alone in the universe? Then that existential hope could crumble, to be replaced by existential dread.
Implicit in the search for extraterrestrial intelligence, whether passive or active, is the assumption that there is someone out there to be found. Frank Drake’s equation estimating the number of broadcasting civilizations in the galaxy has millions of possible solutions, but the one answer that he and everyone else involved in SETI would never believe is this: one—meaning our civilization, and no other. Yet after decades of craning our ears to the heavens, all we have heard in response is what the scientist and writer David Brin termed “the Great Silence.”39 Despite predictions like Drake’s, despite the sheer size and age of the galaxy, which would seem to give plenty of opportunity and space for intelligent civilizations like our own to make their presence detectable, we see nothing and hear nothing. And that should give us pause, and maybe, just a touch of dread. An empty universe may not merely be lonely, but actively hostile to intelligent life—including our own. Or to ask Enrico Fermi’s question again: where is everybody?
For someone whose name was put on the question that has defined the debate over extraterrestrial intelligence, there’s little evidence that Enrico Fermi thought or even cared much about aliens. After the Manhattan Project, Fermi continued to consult at Los Alamos, working on Edward Teller’s design for the far more powerful hydrogen bomb. One day in 1950 Fermi was lunching at the lab with his colleagues Teller, Emil Konopinski, and Herbert York when the conversation turned to a cartoon in The New Yorker showing little green men carrying trash cans stolen from the street. Fermi suddenly asked a question: “Where is everybody?” It was a typically Fermian outburst, a tossed-off query that nonetheless cut to the heart of the debate. If aliens did exist, then why in a vast universe billions of years old hadn’t we seen them yet? Why hadn’t they shown up on Earth to conquer our planet, or at least steal our trash cans? Where is everybody?40
