Arecibo Diaries: Is the Search Wishful Thinking or Hubris

Apr. 24, 2003
by Seth Shostak - Senior Astronomer

Sometimes I feel like an ant.

Actually, that syntax implies that I might have a hankering for some chocolate-covered formicidae, but thats not right. What I mean to say is that sometimes usually after dinner, it seems my mind zooms back in hope of seeing the big picture: trying to get the establishing shot on life, SETI, and just what the heck were doing here in the lush foliage of Puerto Rico. And the first jarring revelation afforded by this wide-angle view is that were just ants.

There have been ten thousand generations of Homo sapiens before us. Since its a fairly good rule of science to assume that anything you observe is typical (until shown otherwise), there may be ten thousand generations to follow.

This is like the ants in my backyard. Those segmented little beasts are only one rank of marchers in a parade of time that stretches dauntingly backwards and forwards. Sure, they think theyre special. They eagerly do their ant thing, hauling foodstuffs back to the nest in long, organized lines. But really, theyre no more special than their great-great-great-great (put in one thousand greats here) grand-ants. Or the countless ants to follow.

It seems pretty analogous to the human condition. But not entirely. For SETI, we figure our generation really is special. Ours is the generation that either at this observatory or some other will break step with the parade, and finally shatter the bubble of isolation that has enclosed life on this planet for 3.5 billion years.

But are these thoughts merely wishful thinking, or worse, just hubris? Thats what I wonder when the after-dinner camera pulls wide. Its traditional to state that SETI began in 1960, with Frank Drakes clever experiment in West Virginia. Consequently, we see ourselves as the first generation thats tried to locate extraterrestrials, and figure that he who dares, wins. But of course were not the first. Karl Friedrich Gauss, whose name is familiar to anyone who has progressed beyond high school algebra, had plans to signal Moon dwellers 150 years ago. His schemes to gain the aliens attention with flashing mirrors or geometric patterns in the forest seem quaint to us now, but Gauss was not dumb (heck, his brain is in a jar at the University of Gottingen!)

So could it be that, 150 years from now, researchers will look upon our efforts as similarly nave? Every week I get e-mail from folks who ask me if were not being narrow-minded when we assume that sophisticated beings would communicate with radio waves or pulses of light. Of course, these well-meaning people dont offer any interesting alternatives (they do, however, offer plenty of uninteresting ones!) But, sure; maybe were barking up the wrong tree. It would be silly and short-sighted to arbitrarily rule that out.

But theres a big difference here. The known universe was claustrophobically small in Gauss time. He was trying to signal intelligence on the Moon, or at most somewhere in the solar system. In the last century, a galaxy-filled universe has opened up. We know that planets are ubiquitous, and liquid water might be plentiful. We also know that technology thats no more advanced than our own could send messages from star to star. Radio waves are fast and energetically cheap. And, although our knowledge of physics is surely incomplete, it could be true (as we think it is) that theres nothing more efficient for communication than electromagnetic radiation. Unlike Gauss, we have the astronomy, and we have the technology. Our approach may not be the only approach, but it is manifestly feasible it could work. Of that were confident.

The truth of this hits me while observing. Every few minutes, the Project Phoenix screens display a thin smear of bright pixels: yet another narrow-band signal. Each is sent through a cascade of progressively finer filters, to determine if its interference or interstellar. As readers of these columns know, so far all have been the former. But looking at these narrow white lines is profoundly reassuring. Our experiment passes the smell test. This is what it could look like, and this is what it would look like. Somewhere out there, if there are worlds easing radio waves into space, their activity would show up exactly so.

Its nice to think that our generation is special. But theres also a reason to believe it. Staring for hours at the screens, I can picture easily picture a discovery. And then I feel less like an ant. They have no future thats different from their past. But we do.