While we are all now familiar with SETI - the search for extraterrestrial intelligence, by searching the skies looking for alien broadcasts - in recent years a lesser known aspect to that quest has been generating plenty of debate. A number of researchers - including one of SETI's most well-respected and recognised scientists, Seth Shostak - have been arguing that a comprehensive approach to searching for aliens should include us trying to make contact with them, referred to as both 'Active SETI' and METI (Messaging to ET Intelligence).
But is this really a good idea? Should we be shouting out our location to the cosmos, when we don't know the intentions of any alien intelligences lurking out there? This is one of the major criticisms of Active SETI voiced in a recent paper on arXiv.org, "Reviewing METI: A Critical Analysis of the Arguments".
The author, John Gertz, points out that in the medical sciences, any proposed experiment must pass ethics review boards. Some experiments are deemed to be too dangerous, or unethical, and are rejected. And yet, "astronomers face no such ethical reviews, since theirs is normally an observational science only", he notes. But "when it comes to METI, which is not observational but manipulative, and on which may hinge the very fate of the world, perhaps they should."
In the paper, Gertz lists and critically evaluates the most common arguments in favour of an Active SETI approach, but finds them wanting:
Whenever one hears a “scientist” assert that ET must be altruistic, or that ET surely knows we are here, or that the closet ET civilization is at least 'x light years' away, ask to see the data set on which they base their conclusions. As of today, no such data set exists. In the absence of any evidence whatsoever, whether one believes that the extraterrestrial civilization we might first encounter will be benign, in the fashion of Spielberg’s Close Encounters of the Third Kind, or ET, or malicious, asin Ridley Scott’s Alien, or robotic, or something else entirely is strictly a matter of one’s personal taste. SETI experiments seek to learn what actually resides or lurks out there in the universe. METI plays Russian roulette without even knowing how many bullets are in the chamber.
It would be wiser to listen for at least decades if not centuries or longer before we initiate intentional interstellar transmissions, and allow all of mankind a voice in that decision. The power of SETI has grown exponentially with Moore’s Law, better instruments, better search strategies, and now thanks to (Russian billionaire) Yui Milner’s visionary investment, meaningful funding. The advances are so profound that it is reasonable to say that the SETI of the next 50 years will be many orders of magnitude more powerful than the SETI of the last 50 years.
[Seth] Shostak, perhaps METI’s most articulate proponent, knows this and has widely predicted that we will achieve Contact within the next two decades. So why can he and his fellow METI-ists not wait at least until then before initiating transmissions?
What do you think? Should we shout out to the cosmos and see if anybody shouts back? Or is it safer not to tempt the fates?
(h/t Norman Redington)