Almost since the moment in 1960 that Astronomer Frank Drake conducted the first radio search for intelligent life beyond Earth from a radio telescope in West Virginia, thinkers from scientists and sci-fi writers to theologians have wondered what would happen if humankind did not merely listen but also sent a radio message outwards as well. So far this has been an exercise in speculation, but that may change. Physicist and leading science fiction writer David Brin is quietly alerting us that there is a brewing debate within the SETI (Search for Extra-Terrestrial Intelligence) community over proposals to shift SETI resources from listening to broadcasting. Instead of using radio telescopes to listen for whispers of others, these “Active SETI” proponents would beam high power radio signals outwards, in effect turning Earth into a bright radio-spectrum beacon shining far into the vastness of deep space.
After listening to this debate for some time, Brin and others in the SETI community have become sufficiently alarmed that they feel a larger conversation is required. To be very blunt, blaring messages into space could affect all of humankind; therefore the decision to do so should not be left to a few obscure researchers who are not even engaging the entire scientific community, much less the public at large. Brin and his colleagues are determined to make this larger conversation happen.
And what exactly is the risk? Consider the unhappy consequences in our own planetary history when technologically-advanced cultures made contact with indigenous groups. From the Aztec to the Inca, the story has never had a happy ending. We don’t yet even have evidence of intelligent life beyond earth, but the consequences of contact with the wrong star-traversing ETs could be so disastrous that SETI pioneers like Carl Sagan counseled forcefully in favor of caution. As parents have reminded their children since time immemorial, there are times when we “should be very small, and very quiet.” Brin, like Sagan before him believes that this is the time to silently listen and discover; broadcasting should wait until we knew more about the neighborhood.
As this debate goes public, it is certain to lead to jokes about ETs and little green men, but I hope the debate doesn’t get lost in the tittering vaudeville these images will inevitably invoke. David Brin is a brilliant researcher with an excellent track record when it comes to foreseeing and facing down big issues long before they even occur to others. I’d love to think that his concern about Active SETI is just an artifact of our paranoid, post 9/11 times, but knowing David as I do, I know to carefully consider his message. So let the debate begin, and let’s hope that is public, robust and far-ranging.