Check out Part 3 of the series here.
Wait wait wait. There are other, less stressful options. I don’t want to end on such a downer note. There is hope for us yet!
First off, remember that the Great Filter might be earlier in our past, on the march from regular life to intelligent life, and we’re already on the other side! Phew! The Great Filter isn’t about absolutes. It’s about probabilities. Space-faring civilizations are so rare that we shouldn’t expect to ever see anybody. But it doesn’t mean that NOBODY makes it to the stars. Maybe we’re just lucky, and we’ve pretty much got the place to ourselves. This logic even applies if the Great Filter is in our future: perhaps MOST civilizations destroy themselves, but someday in the future humanity will put away our destructive tendencies, heal the Earth, and work together in harmony to bring ourselves to new homes among the stars.
Sorry, I’m trying really hard not to roll my eyes. But hey, the point remains, we’ve still got a chance.
Or maybe the Great Filter is still in our future, but it’s less…apocalyptic than we might think.
Maybe galactic colonization is harder than we could even dream of. I mean, the galaxy is a really big place, and the distances between individual stars is greater than our puny human brains can even begin to comprehend. Yes, I know we can put numbers on it like 10 light-years, but that doesn’t mean we can UNDERSTAND the enormity of those kinds of distances. Perhaps even a super-duper-advanced civilization, with unimaginable technologies at its disposal, doesn’t make it very far. Maybe physics is physics, the speed of light the ultimate limit, only certain energy scales available, and so on. Even if that species got a ten-billion year head start, maybe the most they could muster is to spread to a few dozen systems and then call it a day. Or they do it once and realize it’s not worth the effort, so they just stick to their home system. I mean, even in our own solar system there are so many potential worlds that we could turn our energies to making habitable, rather than spending that energy attempting to send lonely craft on impossible voyages.
And sure, those species could pump out trillions of probes…and most of them could simply fail, or malfunction, or peter out, before covering even a fraction of the galaxy. It’s one thing to say “oh yeah we’ll fill the galaxy with self-replicating robotic probes.” It’s quite another to work out the technology, engineering, and energetics to make it possible.
Or maybe galactic colonization is…boring. Or, like, not the end goal of our technological progress. Yes, we’re all obsessed with space travel now, but who knows what priorities ten generations down the line will prefer to work on. We don’t share the same priorities and goals and ambitions as, say, feudal Europe or ancient China, so why should we expect our current to-do list to hold sway? Maybe our descendants will think we were foolish for spending so many resources on space travel, when really it was all an outgrowth of research into intercontinental ballistic missiles. We have to be careful when making assumptions what future humans, or other advanced civilizations, might do given our OWN technological development and directions. Maybe civilizations will be content with observing the stars from afar and otherwise looking after their own affairs. Maybe super-advanced species withdraw from the galactic scene, preferring instead to hold on to their homes and enjoy what they’re got. Or just…they all invent social media and doomscroll themselves into permanent complacency.
Or maybe the Great Filter isn’t so…great. Maybe we do bomb ourselves, but not into oblivion, but just back into the stone age. And we do it again, and again. Maybe intelligent species are out there on some distant planet, but the period of time when they could spread radio messages or robotic spacecraft is so narrow that the vast majority of them are just spending most of their time chucking rocks against each other? In other words, space travel is only possible during a narrow window of time, and all other times species are otherwise invisible.
All of these scenarios would fit the requirements of a Great Filter. Remember, it’s not necessarily about preventing the rise of intelligent species, or even space-faring species. It’s about preventing the development of intelligent species that go on to colonize, explore, and/or probe vast parts of the galaxy, making them easily noticeable to our meager observations. If galactic space travel is difficult, boring, or short-lived, the galaxy could be littered with intelligent species that we would likely never intersect or even hear from.
Either one of these could be the Great Filter, or maybe all these considerations work together, a series of Minor Filters adding up to a single Great Filter. Maybe life gaining a foothold is hard. Maybe gaining intelligence is harder. Maybe the combination of existential risks from technological developments, apathy, and short periods of space travel viability all combine to ensure that the galaxy appears empty, even if it isn’t.
So maybe we’re all good. Maybe the Great Filter is behind us, and we’re one of the lucky few to even make it to this stage, and we’re already on the path to the stars, free to roam and explore a galaxy that is largely ours and ours alone. Or maybe advanced civilizations are out there, not ready and waiting to welcome us into the Galactic Federation, but just minding their own business. And if we look far enough into the future, we follow the same path: not spreading humanity across vast interstellar distances, but just staying chill at home.
Maybe our future is on a totally different path, one we don’t have the imagination to discern yet.
Or maybe we’ll kill ourselves. You know, just in case you forgot.
There’s only one way to find out.
But seriously, where IS everybody?