We’re finding planets left and right. But so far, nobody interesting to talk to. Still, the Search for Extraterrestrial Intelligence (“SETI”) continues. I see SETI’s fundamental outlook as something like this: “With all that space out there, there must be others capable of at least broadcasting in frequencies we can detect.” Imaginations can run wild with that assertion alone, and giddy anticipation of true communication quickly follows (at least for all us nerds that grew up in the shadow of The Day the Earth Stood Still and other timeless SF classics). But the more likely benefit of searching is a little more practical: We might learn something of value.
But what are the chances we’ll find something?
We can guess. But that’s all. Because actually, we have no clue. The answer depends entirely on what we don’t know.
So how do we think of that?
I’ve said this before. We tend to be a bit arrogant as a civilization (and perhaps as a species), and we think that we’re on the brink of understanding darn near everything. To put it in a pie chart, the stuff we think we know, compared to the stuff we almost know, compared to things about which we are entirely clueless, looks to us something like this:
But that is because we tend to be a little full of ourselves. Fortunately, we can look back and learn from the mistaken viewpoints of the past. From Aristotle to Ptolemy to Newton to Hawking, every time a genius comes around, we feel like we’ve been given the keys to the kingdom, and we almost know everything. That’s psychology (or maybe sociology), not fact or science. And the lesson of the past, wherein the knowledge pie chart looks like the one above, is that there is a whole lot more in that beige zone than we imagine.
So, while we do know something, what we know, compared to the two categories of things we don’t know (almost a clue and clueless), is probably a lot more like this:
So we listen. If humanity is still in its technological infancy (which it probably is), then probability is high that anything we detect will originate from something more advanced. It might be hard to recognize. It could be tough to understand. It may also be horrendously dangerous (probably not). But there’s gold in the sky, and we’re looking for it.
For more information about SETI, visit the SETI Institute. Or view either or both of the following videos, the first being Part 5 of Carl Sagan’s Series, and the second being a 45-minute program about SETI.