It's a disturbing question, and one that I seem to get more frequently than before.
"Why are you looking for evidence of extraterrestrials? What's the point?"
While I have always thought that the motivation for looking for E.T. was both self-evident and patently worthy, it's possible that I'm a victim of my own job description. Others don't inevitably agree. Some will opine that there are better ways to spend the money.
"With all the problems we're facing here on Earth -- climate change, environmental degradation, war, poverty and more -- why are we wasting funds looking for space aliens?"
That's the same argument that's often lobbed at NASA's space programs, and at basic research in general. The thrust is that if your work isn't obviously helping to better my lot (or maybe the lot of a lot of others), then you're just friction in the system.
My knee-jerk rejoinder to this all-too-easy humanism is to note that the amount of money involved is tiny. The total funding of SETI (the Search for Extraterrestrial Intelligence) in the U.S. is 0.0003 percent of the tax monies spent on health and human services. And it's not even tax money. The SETI Institute's hunt for signals is funded by donations.
But while pointing out the realities of funding is certainly legitimate, I've recently promised myself to avoid doing so. It gives up too easily, and sounds like a confession: "Yes, you're right. It's a waste, but a very small waste."
Well, it's not a waste. The hunt for other sentience in the cosmos is done for reasons that could be extremely important and that, in any case, gratify the finest aspects of our spirit.
Consider the practical consequences of discovering company among the stars. These benefits are, admittedly, uncertain and hard to predict. They depend on whether we could ever decode signals from intelligence that is not only many light-years distant, but enormously ahead of us in technical ability. We're not going to hear from beings that are at our level -- they won't have the equipment necessary to transmit a signal that today's SETI experiments could pick up. So if a radio disturbance from ET someday floods our antennas, you can be sure that whatever's behind the microphone would judge our own knowledge of science to be merely quaint.
Consequently, if we can make heads and tails of their signal, we could become privy to knowledge that would otherwise remain unknown until developed by our descendants centuries or more in the future. While this manna from the skies could be profoundly disruptive, you can't argue that ignorance is blissfully preferable. It's not.
But what if -- as is thoroughly possible -- we're unable to understand ET's broadcast? What if we just know they're there? In the months following a detection, intense study of the signal source would garner a handful of astronomical facts -- the distance to the senders, a few planetary parameters such as the length of day and the likely mean temperature, and possibly some information about the atmosphere. All of which would be interesting, and even mildly informative (did ET evolve on a world somewhat like our own?) But it would leave us guessing about the inhabitants based on the habitat. And the meaning of the message might eternally elude us.
However, even without that prize, the contest is more than worthwhile. Exploration is an oft-lauded human activity, and one that resonates in the same way that music and good stories do. It's hard-wired into our species (and into many others), no doubt because it has survival value. Exploration occasionally rewards those who accept its risks, usually with new resources.
There's little need to expound on the romantic lure of exploration, for few would dispute it. But there's a special appeal in a search for other-world intelligence. We have a deep fascination for this because, after all, Darwinian mechanisms ensure that all life has a paramount interest in its own species. For us, other thinking beings are subconsciously regarded as potential equals, and interest us as competitors or mates. Of course, real aliens would be neither, but their sentience makes them compelling in a way that extraterrestrial bacteria are not.
Our curiosity is broader than merely the innate interest in cosmic doppelgangers, however. We want to know if intelligent life is some sort of wildly improbable accident. Are we the only members of the Galaxy that can actually understand what a galaxy is? Could Homo sapiens really be the pinnacle of Creation -- the cleverest critters in the cosmos? If we learn the answer is "no," that would affect our philosophies forever.
In the past I was seldom asked why we hunt for extraterrestrial company, only how. Perhaps the realities of today's world have narrowed our vision to the near-to-hand. SETI is too speculative. And sure, concern for the immediate and the demonstrably practical is helpful in the short-term. But if we only look nearby, we can't see where we're going.
Frank Borman remarked that "exploration is really the essence of the human spirit." Borman's an astronaut, so he was tipping his hat to his own career. And so am I when I say that SETI is done out of curiosity, and is both tremendously exciting and undoubtedly worthwhile. It might alter the trajectory of our civilization. But more than that, a search for others feeds the best in our nature.