Given my low opinion of SETI, you may find it surprising that Contact is one of my top 5 favorite films. Aside from the clever way it deals with a number of deep philosophical issues, the positive way it portrays atheism, the cool special effects (the zoom-out at the beginning choked me up the first time I saw it, but luckily my girlfriend didn't notice!), and the well-constructed plot, I pretty much fell head-over-heels for Ellie Arroway. How could you not? She's brilliant, sexy as hell (of course, Jodie Foster is primarily responsible for that), and passionate about what's important to her (and it isn't the ho-hum of children!). Sadly, however, she is possessed by a fixed idea--just as possessed, by the way, as is Palmer Joss, her love interest in the story, by the idea of God. Like I said, I guess we all have our blind spots.
SETI is the brainchild of astronomer Frank Drake, who also came up with what is known as the Drake Equation, which I'll get to in a moment. Drake has been searching the skies via radio waves for 45 years, now, without uncovering a shred of evidence of alien intelligence. When confronted on this, Drake's response strikes a disturbingly familiar chord: "Absence of evidence is not evidence of absence."
Such is the response of one who is defending a hypothesis that is not falsifiable, and that is exactly what is wrong with SETI. The excuse is always, "We haven't looked long and hard enough." When will that be? When does absence of evidence finally become evidence of absence? Back circa 1994, when Congress - having spent over a billion dollars on SETI - finally cut off the public funding, Drake predicted "the imminent detection of signals from an extraterrestrial civilization." He went on, "This discovery, which I fully expect to witness before the year 2000, will profoundly change the world." Here it is, 2005, and SETI, much like the doomsday religions that predicted the end of the world back in 2000, is still going.
So, what about the Drake Equation? Its purpose is to try to come up with an estimate of how many intelligent civilizations are likely to exist in our galaxy. As an aside, I can't figure out why the quantity R, which is the number of stars that form in the galaxy each year, is even in the equation in the first place. What does R have to do with anything? New stars are not very likely to have life-bearing planets in orbit around them, so WTF? Why not just start with the number of stars in the galaxy? If you have an answer for this, I'd love to hear it. But the real problem with the equation is that virtually every variable is a complete unknown. We don't know how many planets there are around most stars. We don't know how many of those might incubate life. We don't know how many of those might evolve intelligence... We simply have no friggin' clue, so the equation is useless even without the quantity R. Assigning a value to a variable is pulling a number out of your ass, and bears a vague resemblance to an act of faith.
Who knows? Maybe tomorrow they'll get lucky and some benevolent super-race of aliens will beam down plans for a wormhole generator, transforming our lives forever. The occurrence of such an event still wouldn't transform SETI into science.