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The Big Picture

December 09, 2003

by Dr. Seth Shostak, Senior Astronomer

Do you think the guys who built the Golden Gate Bridge knew what they were doing?

Oh, sure, they knew what they were doing day-to-day.  They were expert in spinning out steel cables and wrangling hot rivets into fish plates.  They knew a lot about such things, and if you asked them about their jobs, Im sure thats what they would describe.

But if you pressed them for a bigger point of view, I dont know whether youd get much past were building a bridge.  The enormous change in the San Francisco area wrought by this construction was too vast to be appreciated or even foreseen.

To some extent, I sense a kinship with those steelworkers here in Arecibo.  The actual search for signals beamed from the warm landscapes of another planet is an exercise in minutiae.  Is PDM 35 back on-line?  I think weve got to revert to the previous software code  Why is the pulse detector flooding out? 

Its all about corralling a feisty brew of digital hardware and specialized software into doing a very difficult job: computing and examining 88 million channels of radio static every three minutes.  Without attention to detail, this bridge wont take shape.

However, it occasionally happens that someone usually a visitor will intrude upon the control room, and force us to think about the broader view.  These outsiders are invariably excited about the premise of SETI, and its always entertaining to watch as they lean over the monitors to carefully examine each signal that we detect and check.  Of course, we see such signals (mostly interference from satellites, radar, and unshielded electronic equipment) many times a night.  Night after night.  To us, theyre pretty routine.  But to the novitiates who visit, this night is different.  This signal is different. 

After all, it could be the big one.

And the point, of course, is that it could.  If it were, we would realize it only slowly.  The system software would continue to slew the telescope back and forth, testing to see if the signal persisted and came only from the direction of the star system under scrutiny.  Within a few hours, the rotation of the Earth would inevitably cause us to lose track of the star, and we would patiently wait until the morrow before resuming our examination.  After a few days of consistent detections, wed ring up another observatory and have them take a look.

All of this is common knowledge.  And just about everyone agrees that if we found a signal from another world, the media would bust a gut.  There would be press conferences, interviews, books, and guest appearances on Oprah.  After that, there would be policy planning meetings with the science community, and urgent efforts to learn all we could about the newly found signal.

But thats all immediate stuff: comparable to the first week after the Golden Gate Bridge opened for traffic.  What would be the consequences years and decades later?  How would societys landscape change?

No one knows.  To a large extent, the answer depends on whether we could ever book success in decoding the signals message.  That might not be in the cards unless the extraterrestrials have an altruistic streak, and fashion their broadcasts to be easily understandable.  Even if they dont and we cant, humankind would still have proof that intelligence is more widely spread than the claustrophobic confines of Earth.  Many pundits say that this knowledge would change our philosophies and our world view.  But exactly how, and to what effect, are highly speculative questions.

We inhabit an island, an isolated culture whose history is vast and deep.  Someday, perhaps soon, we might find evidence of other societies washed up on our shores; an undecipherable message thats come to us from a civilization far beyond the reach of our boats.  Theres no doubt that we would be profoundly changed, but in which direction is unclear.  And yet, it seems certain that to know, instead of to wonder, would be a good thing.

Meanwhile, we busy ourselves with the details, and keep on building.