A passionate scientific debate was held this week in San Jose at a meeting of the American Association for the Advancement of Science sponsored by the SETI Institute. SETI — Search for Extraterrestial Intelligence — wanted to bring together scientists of many disciplines to discuss whether efforts to contact alien civilizations should remain “passive,” i.e. listening for signals only, or go “active” by actually composing a message and targeting specific stars that might have an earth-like planet orbiting them.
The active/passive SETI debate has been going on since the early days of the program. Many scientists who support active SETI think that both listening for messages or evidence of intelligence as well as sending our own message to the stars increases the likelihood that we will eventually make contact.
But some passive SETI proponents believe that it’s too dangerous to send out a signal inviting contact. Even if the chances of a hostile alien race hearing the message and coming to earth to destroy us is extremely small, why take the risk? If the active SETI people are wrong, no one will be around to criticize them for it.
The aliens don’t even have to be hostile to be a threat. Earth’s own history is filled with examples of technologically advanced civilizations making contact with comparatively primitive cultures, only to see the primitives decimated. Surely a civilization advanced enough to travel through space to reach the earth knows this, which may be another reason we’ve received no indication of intelligence elsewhere.
The San Jose conference was held to examine these questions in a serious forum. Dr. Seth Shostak, long time head of the SETI project, thinks the time has come to adopt guidelines for active SETI research.
High on the agenda is whether such a move would, as he put it so starkly, lead to the “obliteration” of the planet.
“I don’t see why the aliens would have any incentive to do that,” Dr Shostak tells me.
“Beyond that, we have been telling them willy-nilly that we are here for 70 years now. They are not very interesting messages but the early TV broadcasts, the early radio, the radar from the Second World War – all that has leaked off the Earth.
“Any society that could come here and ruin our whole day by incinerating the planet already knows we are here.”
Clash of culturesHis argument isn’t entirely reassuring. But neither is the one made by David Brin, a science fiction writer invited to speak at the AAAS meeting, who opposes the plan.
“Historians will tell you that first contact between industrial civilisations and indigenous people does not go well,” he told me.
Mr Brin believes that those in favour of active Seti have been “railroading the public into sending a message without a wide and detailed discussion of what the cultural impact might be”.
He does not fear a Hollywood-style alien invasion and thinks the likelihood of making contact is extremely low. But the risks, he argues, are extremely high and so merit careful consideration before anyone sends out a signal to potentially habitable worlds.
“The arrogance of shouting into the cosmos without any proper risk assessment defies belief. It is a course that would put our grandchildren at risk,” he said.
Shostak is being far too optimistic. Although we’ve been beaming radio programs, radar signals, and TV shows into the cosmos for 70 years, that encompasses only a miniscule percentage of the Milky Way galaxy. Any risk assessment would have to include the certainty that we’ve barely scratched the surface in reaching potential intelligent species.
We have explored only a small piece of the sky so far and there are several good reasons why we may have missed a message in past sweeps. We may not be technologically advanced enough to decode it. We may lack the imagination to recognize a message even though it’s been right in front of us. But the most likely reason we have yet to achieve success in our SETI efforts is that there just aren’t that many civilizations transmitting.
Does this mean that there are fewer advanced civilizations than we thought? This is a definite possibility. It could very well be that the deck is stacked against any intelligent civilization reaching our level of sophistication. Rouge asteroids or comets, an unstable sun or moon, a nearby supernova not to mention the possibility that the denizens of any technologically advanced society could blow themselves up all make it a distinct possibility that while intelligent life is abundant in the universe, it doesn’t necessarily stand to reason that it survives long enough to reach out and try and touch someone.
Something else to consider before we begin an active SETI program; the probability that the dominant life in the universe are intelligent machines:
University of Connecticut philosophy professor Susan Schneider certainly thinks so. In her new paper “Alien Minds,” she proposes that by the time civilizations are able to communicate by radio, they’re a few short steps away from developing artificial intelligence. One they reached that level of advancement, they may have opted to upgrade their biology to something that’s a biomechanical hybrid or something entirely synthetic. There could be a whole mess of Borg out there, in other words.
She also argues that those civilizations will be older than ours. If a dominant intelligent lifeform developed even a million years before humanity, and within centuries uploaded their brains to alien computers, those computers are likely to be vastly more intelligent than we can even fathom.
Such machines wouldn’t have an interest in spacefaring because they would have already unlocked the mysteries of the universe and would have little need to go exploring. Then again, if they thought we had something of value to them, they may decide to come and take it. It’s not likely they would have programmed altruism, pity, remorse, or another emotion into the system.
But if we were to undertake an active SETI program, what should we say?
Some involved in the discussions believe we should send a sanitised account of ourselves, leaving out parts of our history we aren’t proud of and putting a positive spin on our achievements – as if our species were attending a job interview or first date. Dr Shostak disagrees. He thinks the only way to win over the aliens is to be ourselves.
“My personal preference is to send the internet – send it all because if you send a lot of information then there’s some chance that they’ll work it out”.
I wonder what the aliens would make of porn?
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