We Are Not Alone

Who isn’t captivated by the search for alien life? Even if you don’t look up at the night sky and wonder who’s out there, you’ve probably enjoyed the excitement and razzle dazzle of artists from H G Wells (War of the Worlds) to director Roland Emmerich (Independence Day), who’ve given us thrilling depictions of aliens for more than a century.

Or you might have seen a mildly successful film from 1997 called Contact, directed by Robert (Back to the Future) Zemeckis from a story by astronomer Carl Sagan. In it, Jodie Foster plays a determined astronomer fighting bureaucratic indifference for something called SETI — the Search for Extraterrestrial Intelligence.

If you didn’t know SETI was a real initiative or that it turns 50 this year, it might make you glad there’s a serious, level headed and scientific approach to searching for life beyond Earth, carried out by a loose association of scientists who devote their time and expertise to a range of studies and data. One is author and cosmologist Paul Davies, and he tells us where SETI’s at in his new book The Eerie Silence.

Based at the Arizona State University’s Beyond Center for Fundamental Concepts in Science, Davies has a long history of thinking and writing about the likelihood of life elsewhere in the universe. While he admits the search for extraterrestrial life is a long shot Davies thinks it’s an innate drive in us, saying “We just know it’s one of those subjects we should think about and investigate.”

The slashing of NASA funding and the decline of the US space program (when the US retires the space shuttle fleet this year it won’t even have a working space craft in service) might make you think programs like SETI are in dire straits, but Davies says astronomy’s seldom been in healthier shape — especially in Australia. Along with the Hubble space telescope and other successful astronomy programs, our bid for the Square Kilometre Array radio telescope (which would be located in WA) puts a good range of tools at SETI’s disposal.

It’s going to need them. When it comes to finding extraterrestrial life any metaphor you can think up (a needle in a haystack, a single fish in the entire ocean) pales beside the sheer numbers and distances involved, and the almost infinitesimal extent of the technology we have to use on them.

Radioastronomy makes it easier. Rather than staring through telescopes at a tiny sliver of sky most astronomy today is done by computers crunching data to look for abnormalities. But the chances of success are still dispiritingly remote. Tell most people there are more stars in the universe than grains of sand on the face of the Earth and they’ll tell you life elsewhere is certain — the law of averages seems to demand it.

But to a scientist there’s a deeper problem than maths. As Davies explains in several of his books like 2008’s The Goldilocks Enigma and now The Eerie Silence, we might know of plenty of planets with life-harbouring conditions but we simply don’t know how easy it is for nature to kick life off. Until we have an idea what changed an amino acid into a protein, then DNA, then a cell, we have no idea how likely it is to have happened anywhere besides here at home.

It might have been a one in a trillion shot, so unlikely the perfect storm of conditions that gave rise to it have only converged once, and we’re living proof. The other possibility is that the instigating process is relatively common — in which case neighbours cut off only by the physics of vast distance are all around us.

Either way, forget everything you’ve learned from TV and the movies. The Eerie Silence isn’t about strange grey bipeds crashing at Roswell and hiding at Area 51 or descending into parks in Washington DC asking us to take them to our leaders. Davies reminds us we might not even know other life if we were looking at it.

“Other forms of life might simply be much, much smaller than even the smallest bacteria we know,” he says. “They may not appear very life like, sitting for longs periods of time and not doing much, but they’d technically cross the threshold between non-living and living. When we go looking for life like it is on Earth, we might be overlooking it.”

Davies adds that a lot of SETI people go out of their way to distance themselves from UFO stories. The science of searching for life is a world away from waiting for a coded welcome message fired straight at us from far away, and the first thing we have to lose is our tendency to anthropomorphise — to apply human social inclinations on organisms that are probably nothing like us.

“To try and guess what an alien civilisation would be like is almost impossible because we’re dealing with literally alien minds,” he says. “We’ve got only the most general principles to go on. We have to ditch not only the Hollywood version but also the popular scientific view and think in much more radical terms. So much conjecture is based on what we’d do — how do we go about these things or what will our future hold or how will we tackle certain problems or develop certain technologies? It’s not gong to be very illuminating. We have to think much more out of the box.”

What makes SETI’s job even harder is what we’re likely to see. Even if the universe is crawling with life, the number of life forms that are civilised and social enough to wonder if we’re out here will be a tiny fraction, the civilisations with the technology to search for us a tiny fraction of that tiny fraction in turn. It might be a biochemical shift that doesn’t adhere to the radio-spectrum data profile we were expecting from a specific world. Even if alien technology’s involved it might be the equivalent of a species who left the car on while ran into the shops, knowing they’d be back in a few millennia — something Davies suggests.

“Much more likely is that we’re going to get evidence we’re not alone through spotting the signature of some sort of alien technology on some distant planet,” he thinks. “A process, object, system or structure that simply couldn’t have a natural origin.”

As well as his other duties at Arizona State, Davies is part of the Post Detection Task Group, an advisory body that’s ready to advise governments, religions and the other representatives of humanity if we do get the big news one day. But Davies admits they have no legal standing and can’t impose recommendations on anybody.

So far, the only control they’ll have will be if someone from inside the SETI system makes the discovery, whereupon the Group’s decided it will keep the co-ordinates secret. The theory is that we can agree on what to tell our new neighbours to represent all of us rather than flood them with a torrent of quasi-religious, nihilist and conflicting socio-political standpoints that might frighten them off altogether.

So if we get the cosmological equivalent of ‘Hi, here we are!’ we can finally stop wondering if we’re alone and start wondering whether they’ll come in peace. But that’s another story…