Chapter 19: The Great Filter: Do We Live in a Dead Universe?
“You have to think if we’ve been visited by extraterrestrial life it was like a zookeeper walking into the chimp enclosure: He looks around, takes some pictures, then leaves without interacting significantly with the environment. Meanwhile the chimps have no idea what the fuck just happened.” ― J. Richard Singleton
Like most folks raised on steady diet of science fiction, for many years I’ve been disappointed in the apparent absence of extraterrestrial life in the universe. Except for those who purport to have had a close encounter of the decidedly alien kind, we’ve all learned to scale back our expectations and breathlessly await the announcement that our Mars probes stumbled across a slime mold, assuming that discovery of any kind of life, no matter how simple has great existential significance. And indeed it does, but not in the way you’re thinking. If we find multicellular life anywhere, yet continue to fail in our efforts to make first contact with something that can carry on a conversation, we are essentially screwed. That’s right. At this point, tripping across evidence of multicellular life anywhere but Earth spells our ultimate doom. Don’t run for the bunker just yet. Follow the dismal logic.
The Fermi Paradox is that old saw of Ufology which points out how odd it is, given our Sun is a relatively young star, and that our galaxy contains billions of stars (many billions of years older than the Sun), a notable portion of which might be assumed to have vaguely Earth-like planets, that we still have no concrete evidence of the existence of extraterrestrial civilizations. Since we are relative newcomers in the galactic neighborhood, one could reasonably assume that at least some portion of these civilizations would have mastered interstellar travel, and by conservative estimates they should easily have been able to colonize most of the inhabitable galaxy in as little as a few tens of millions of years. Sadly, there is no convincing evidence that this is the case, leading many theorists to conclude that either (1) everybody is really scared of something and thus staying quiet; (2) intelligent life is inherently self-destructive and once any civilization reaches a sufficient level of technological advancement it implodes catastrophically, or (3) we are well and truly alone in the universe. These are all equally unsatisfying propositions as we don’t like to consider what would make everyone in the galaxy hide their heads under the covers, we are a little too enamored of our big brains and technological progress to admit we’ll probably blow ourselves to hell at some point, and we’re essentially sociable creatures that would probably die from loneliness if there was nobody out there to impress with our wit and charm. There is also the remote possibility that we are the recipients of an organized galactic conspiracy of “shunning”. Perhaps we smell. This is unlikely, as any sufficiently advanced technological civilization will no doubt have invented Jovian strength deodorant and offered it to us along with world peace and the cure for cancer.
This led an incredibly depressing economist named Robin Hanson to first propose what has been deemed “The Great Filter” to explain the fact that the Universe, apart from Earth, appears to be vast, empty, and dead. The Theory of the Great Filter suggests, dovetailing off the famous Drake Equation, that the evolutionary path from the supportability of life to the colonization of the universe would proceed from (1) the existence of a potentially habitable planet to (2) reproductive molecules (such as RNA) to (3) simple single-celled life to (4) complex single-celled life to (5) sexually reproducing life to (6) multicellular life to (7) tool using critters with sizable brains to (8) modern technological civilization to (9) an explosion of colonization and expansion into the universe. Since we have no clear evidence of alien colonies anywhere, Hanson’s theory maintains that one of these steps must be extremely improbable. Given the fact that the galaxy isn’t teeming with extraterrestrial homesteads, a reasonable conclusion would be that the final step of outward expansion is rare, if achievable. Now, here’s where things get nasty. Imagine we find multicellular life on Mars or frankly anywhere in the observable universe, but continue to lack any but our own dubious example of sentient life. This would suggest that the path from the formation of habitable biomes to multicellular life is a relatively easy one. Furthermore, the implication would be that the difficulty is either in forming a complex enough brain to set one on the path to conquering the galaxy, or that once we’ve got the know-how and gumption to start launching ourselves into the starry night, something inevitably goes cataclysmically wrong. Either option sucks since the ultimate conclusion we must come to is that we will never find anyone out there to talk to, or we are certain to usher in our own extinction. I for one am putting my money down on not finding multicellular life on Mars, because if we do find life, it’s fairly clear that in the long run we won’t be needing money much anyway.