Why the search for alien life matters.

“The universe is not only queerer than we suppose, but queerer than we can suppose.”
—British biologist J.B.S. Haldane

It’s always good fun when scientists argue about aliens, most of all because they don’t have any proof aliens exist. They just like to hypothesize that they might. It provides a rare opportunity to watch great rational thinkers and empiricists become poets and dreamers, imagining other creatures, other life forms, and other worlds, and indulging in what almost appear to be flights of fancy.

And we have had plenty of opportunity in recent years, because more and more scientists have begun arguing that intelligent life must exist beyond Earth, despite the fact that there is no evidence of it. The science has not changed; scientists have. In fact, all of us now are more likely to believe in life beyond Earth than our grandparents were. These scientists are part of the E.T. Generation, those who as kids watched the cuddly alien (based on an imaginary friend Steven Spielberg conjured when his parents divorced), cried when he went home, and started to believe extraterrestrials might be out there. E.T. made aliens appealing, and not frightening, to children across the world.

When theoretical physicist Stephen Hawking warned this week in a Discovery Channel documentary that aliens might be unfriendly invaders not at all like our candy-munching friend from the ’80s, he was not doing so because there was fresh evidence of faraway overlords. He was simply speculating. According to Hawking, if aliens finally were to respond to our radio signals, it might be like waving to pirates equipped with weaponry we have not even dreamed of and welcoming them aboard our little ship. “The outcome,” he said in the film, “would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans.”

It’s a sobering thought: why are we wasting all this money on trying to contact aliens if they’ll only rip our throats out and steal our planet? Hawking explained, “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet. I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach. To my mathematical brain, the numbers alone make thinking about aliens perfectly rational.” Quick, let’s hide!
Is this a mathematical conclusion? Scientist Paul Davies, a professor at Arizona State University who chairs the Search for Extraterrestrial Intelligence (SETI) Post-Detection Taskgroup, thinks not. He says he was completely baffled by Hawking’s comments and dismissed them as part of a “popular, not a deeply considered position, repeating Hollywood myths.” Davies has just written a book on how we must rethink the hunt for E.T.s, titled The Eerie Silence: Renewing Our Search for Alien Intelligence. He argues that since there is no known mechanism for turning nonlife into life, we cannot calculate the odds of other intelligent beings existing. Math cannot prove the existence of aliens: “It is not a scientific judgment, it is just a belief.” Further, no matter how horrible they might be, we cannot hide our planet from aliens, and the universe is so enormous that any contact is more likely to be exploration than colonization, and it would most likely be one-way (could they travel 1,000 light-years and back again in one trip?). The greatest danger they might pose, Davies argues, is not that they will arrive with guns blazing, but that any new and transformative knowledge—about, say, alternative-energy sources—might destabilize our society, in the same way that giving nuclear weapons to primitive tribes might.

What Davies can’t work out is why a belief in aliens has become fashionable in the scientific community in the last decade. It may be because we are all more credulous now. About 40 percent of Americans now believe that alien abductions may have occurred, up significantly from the 1980s, when only 25 percent believed in them. We can’t blame it all on E.T., though. Gallup polls suggest that the greatest jump happened in the 1960s—in 1957, one in four thought there was a possibility flying saucers were from outer space. In 1966, asked if there are “people somewhat like ourselves living on other planets,” one in three said yes. Asked the same question in 1973, almost half said yes, as they did again in 1990. What is most curious about belief in flying saucers and alien life is that there is a strong skew toward men and those with college educations. Women and the less educated are more skeptical.

This growing belief has not been matched by fresh data. Since 1960, we have been engaged in a so far fruitless quest to send radio signals out to aliens thousands of light-years away. Appearing 50 years later, Davies’s book is intended to be a wake-up call for those involved in SETI, which has only resulted in eerie silence to date. Wryly, Davies quotes Donald Rumsfeld on weapons of mass destruction—absence of evidence is not the same as evidence of absence—and argues that the search should be broadened beyond radio (which we do not know aliens would even use) to look for other signs of intelligent life around us, even in our DNA or the biosphere. For example, it could make sense to look for signs of a parallel or older life that may exist in our physical world but that we have not yet recognized.

And then? What would we do if we did make contact? What would we want to say? Who would speak for Earth? In 1977, the Voyager spacecraft carried hellos in 55 languages, music, and words from President Jimmy Carter and then–U.N. secretary-general Kurt Waldheim, which seems a bit boring. Davies, of course, thinks we should show off our scientific knowledge, sending Maxwell’s equations, the field equations of general relativity, Dirac’s equation of relativistic quantum mechanics, and so on. (Personally, I’d prefer a copy of NEWSWEEK, a fully stocked Kindle, an iPad, and unlimited iTunes.)

The search is worth it, though. If we find nothing, it still forces us to think about who we are and why we are here. Even flights of fancy can serve a deeper purpose. As Arthur C. Clarke, futurist and author of 2001: A Space Odyssey, once said, “Sometimes I think we’re alone in the universe, and sometimes I think we’re not. In either case, the idea is quite staggering.” Scientific pronouncements are so often parched of wonder that diving into alien debates is refreshing: it makes us marvel that we even exist, and at the extraordinary way the universe stretches and confounds us. Hawking worries about beastly, hostile invaders, and Davies dreams of a cosmic golden age. The span of the universe, and the music it spins to, is more than we can imagine, more than we can calculate, more than we can dare to wonder. It is, literally, beyond us. And that is why it is still worth straining our eyes and cupping our ears toward space.