Giving up the Ghost: Is SETI Futile?

Seth Shostak, the Senior Astronomer at the SETI Institute, had an article published at on January 18th 2007 entitled When Does SETI Throw in the Towel?, wherein he writes about the search for extraterrestrial life:

Indeed, my personal feeling is that if SETI hasn't turned up something by the second half of this century, we should reconsider our search strategy, rather than assume that we've failed because there is nothing–or no one–to find. Would I ever conclude that we've searched enough? Would I ever truly give up on SETI's bedrock premise, and tell myself that the extraterrestrials simply aren't out there? Not likely. That would be to assume that we've learned all there is to know about our universe, a stance that is contrary to the spirit of explorers and scientists alike. We might yearn, or even need to believe that we are special, but to conclude that Homo sapiens is the best the cosmos has to offer is egregious self-adulation.

Michael Anissimov, on the other hand, suggests:

Believers will never abandon the search. If the aliens aren't swallowing stars right in front of our face, they must be broadcasting on the electromagnetic spectrum. If they aren't broadcasting on the electromagnetic spectrum, they must be sending each other neutrino bursts. If they aren't sending neutrino bursts, they must be somehow manipulating the fabric of spacetime itself to covertly send messages. Like theists, they're willing to bend over backwards to get the assumptions they need to give their belief any chance of success.

Why we've yet to be legitimately contacted is merely due to lack of time, a possible solution to the Fermi paradox, "the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence of contact with such civilizations". Rasmus Bjørk, a physicist at the Niels Bohr institute in Copenhagen, comments in The Guardian about a computer simulation he designed:

Extra-terrestrials have yet to find us because they haven't had enough time to look ... if the alien ships could hurtle through space at a tenth of the speed of light, or 30,000km a second ... it would take 10bn years, roughly half the age of the universe, to explore just 4% of the galaxy.

And even should self-replicating and intelligent probes propagate throughout the galaxy, creating more and more copies of themselves in hopes of finally accomplishing something, anything, these Man's Best Friend may not be entirely loyal. Adam Crowl suggests:

Many assume that as soon as intelligences can make autonomous self-replicating robots then that's what they'll do, sending them forth with a 'mission' to colonise the galaxy with their kind of intelligent life. A self-replicator smart enough to be called 'intelligent life' is a 'person' in my view, but an arguably important aspect of personal identity is freedom and creativity, and I suspect even the longest-lived 'persons' will fatigue in the face of a task like colonising every star in the Galaxy ... And why should self-replicating probes colonise at all? They're intelligent enough to decide that for themselves, but such vastly long-lived entities may well develop a wholly different set of motivations to us organic beings.

These quotes are a backdrop to a tough decision I've recently made: stopping my SETI@home client which has been using my computer processing power to analyze radio telescope data for the last five years. My first contribution was December 24th, 2001, shortly after I purchased a new PowerMac and, with the rise of the new software, BOINC, I received the illustrious user account #123456. I'm saddened to be doing this but, even though I'd shake my fist at the sky should we discover something tomorrow, I won't regret the choice.

I'm still a believer and I revel at the thought of what proof positive would do to our little civilization. I don't think, however, that we'll be the ones to find communicable life within my lifetime, nor do I think I'll win the lottery anytime soon (especially since I don't play it, the same attitude "aliens don't exist"ers cop). Just as the people who don't have the money to spend on said tickets continue to waste it on a hopeful chance of a lifetime, my processing power is becoming more and more valuable as I do more and more concurrently. A lottery win and an alien "sup?" will certainly change lives, but finding life wouldn't truly affect my day to day. No alien emissary would be allowed to wander the populace, nor would I be able to shake, or do something else suitably naughty, to its tentacle. Dying at the hands of an alien invasion isn't entirely the contact I'd like to make, nor do I want the self-doubt inherent in an encounter no other sane person believes.

Good bye, SETI@home: It's been five good years, but I need to make differences where I can, not where I hope.