Anybody Out There?
By Guy Kahane
These days it seems as if every couple of weeks or so we get reports about newly discovered planets that are ever more similar to Earth. The most recent discovery, planet Proxima b, is the closest planet found so far; Scientific American called it ‘the Earth next door’. Last October, an amateur group of astronomers noticed that the star KIC8462852 was flickering in an odd way, its brightness changing by up to 22 per cent, a much larger change than could be explained by any familiar cause. Some science fiction fans speculated that this might be a ‘Dyson Sphere’—signs of a super-advanced civilization desperately trying to harness energy from their sun. No convincing explanation of this effect has been found so far, and another star, called EPIC 204278916, was recently spotted exhibiting the same mysterious flicker. Then it was reported that Russian radio astronomers recorded a two-second burst of mysteriously strong radio waves coming from a sun-like star in the Hercules constellation.
We know we shouldn’t get too excited. Even if there are numerous Earth-like planets out there, they may all be lifeless. And scientists will probably eventually find perfectly natural explanations for these strange flickers and signals (the Russian report already seems to be a false alarm, caused by terrestrial interference). But still: it’s hard not to anticipate the day—perhaps in the coming few years, perhaps later in our lifetime—when strong, perhaps undeniable evidence of intelligent life elsewhere in the universe will emerge. It sure feels as if that will be an incredibly important discovery. Arthur C. Clarke once said that “there are two possibilities: either we are alone in the universe, or we are not. Both are equally terrifying.” But it’s not that easy to explain why.
Of course, if there is intelligent life out there, these extra-terrestrials may one day visit us, and they might not be incredibly friendly—a possibility that is terrifying in obvious ways. But even if we managed to discover signs of intelligent life on Proxima b, it is far from obvious that we would ever be able to communicate with the Proximans, and it could take many decades, possibly longer, to figure this out. As for mutual visits, for all we know it could be centuries before they become seriously feasible. But it seems that discovering intelligent life out there would be an immense discovery even independently of these practicalities (or impracticalities). I think it would change the way we think about ourselves. But spelling out how and why isn’t so straightforward.
You’d expect that philosophy would be able to help us here, but I think that most philosophers would be embarrassed to write (or even think) about aliens. You certainly won’t find much discussion of extra-terrestrial life in recent moral philosophy. This isn’t surprising. Moral philosophy is largely focused on questions about how we should treat each other and, and sometimes, more broadly, about what kind of lives we should live. But until the aliens knock on our door, there’s obviously no need for the sub-field of Alien Ethics. And whether or not we’re alone in the universe won’t directly change how we ought to live. It’s rather a question about, to use the clichéd phrase, ‘our place in the universe’.
I want to suggest one way in which it would matter immensely whether or not we’re alone in the universe—one way of explaining why Arthur C. Clarke was right. Suppose that in a hundred years from now, we destroy ourselves using nuclear weapons, or in some other way. That would be an awful thing. It would involve an unthinkable amount of suffering and death. And on top of that unimaginable evil, there would also be the loss of all the things humanity could have potentially achieved, of billions and billions of people who could have lived in the future but, because of our foolishness, never will.
But how important would our extinction be? Well, whether we stay around is obviously pretty important to us. But would it matter much beyond that? I think that this almost entirely depends on whether we are alone in the universe. Whether something is good or bad, wonderful or evil, largely depends on the nature of that thing. Suffering just is bad, helping others good, etc. But how important something is depends on what else is around. It depends on the value something has, as well as the difference to overall value that something makes, compared to other things. It’s far more important, in this sense, whether Hilary Clinton has pneumonia, or whether Donald Trump is telling the truth, than whether we have pneumonia, or are telling the truth (journalists are, rightly, a bit less interested in the latter than in the former). Or to give a very different example, Shakespeare’s work is so seminal because there is so little that compares to it, and because it has had such a huge influence. If Elizabethan drama was blessed with several other authors as great (or greater) than Shakespeare, then the loss of an early copy of Hamlet won’t matter as much—even though Hamlet, considered in itself, wouldn’t be any less wonderful.
In the same way, if we’re alone in the universe, or even one of a handful of intelligent species, then we would matter on the cosmic scale in a way we obviously wouldn’t if the universe is teeming with intelligent life. It would still be sad if we extinguish ourselves but, on the large scale of things, it just wouldn’t be that much of a loss. Intelligent life would go on, other civilizations would go to do great (or horrible) things… Our disappearance won’t deserve any special notice. It would be no more than a sad footnote.
This is why it would be terrifying both to discover that we are alone in the universe and that we aren’t. If we aren’t, and there is intelligent life all around, then we are pretty insignificant—important to no one but ourselves. But if we are alone then we are immensely important. If we destroy ourselves, then we are destroying not just ourselves, but also the only intelligent life in the universe, something incredibly special and rare… If all life on Earth gets extinguished, this might be the end of all value in the universe. As a species, we don’t seem to be bothered much by our (current) cosmic loneliness, but if it is confirmed, then everything we do (or fail to so) acquires an added layer of importance. This isn’t something to be terribly proud about—it’s not as if we would deserve credit for the cosmic coincidence of our singular existence. But it would be a great responsibility—actually, a pretty terrifying burden.
Now there is a lot more to be said. Does it really make sense to speak of things being important ‘on the cosmic scale’, as opposed to merely important to us? And can things really have value beyond the value we humans confer on them? I try to answer these questions, and a few others, in this rather long paper. But let me end by quoting some lines from the poem ‘The Ball’ by the Polish poet Wislawa Szymborska, who makes the main point far better than I am able to, and with far fewer words:
“As long as nothing can be known for sure
(no signals have been picked up yet),
as long as Earth is still unlike
the nearer and more distant planets,
let’s act like very special guests of honor
at the district-firemen’s ball
dance to the beat of the local oompah band,
and pretend that it’s the ball
to end all balls.”