In the latest science news, a planet has been discovered which could potentially support life. A neighborly 20.3 light years away, Gliese 581g has liquid water and enough gravity to maintain an atmosphere -- making it a fairly good imitation of earth.
Great news, right? Homo sapiens now has the potential to spread across the galaxy, leaving the barren rock of Terra behind as we forge into the great empty unknown. Unfortunately, the actual "getting there" part is still a ways off. Even worse, this discovery may not bode well for the future of humanity.
What could be so ominous about discovering a distant, earth-like planet? It all boils down to the Fermi paradox. From Wikipedia, the Fermi paradox "is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations." In other words, if they're out there, why haven't we seen them yet? Given the extremely long lifespan of the universe and the enormous number of galaxies and stars, the laws of probability would indicate that any space-faring life form should have colonized the entire universe by now.
The lack of evidence for extra-terrestrial life, in spite of the enormous opportunity for its growth, requires some serious explaining. One possible cause - the lack of earth-like planets which could support life - has just been ruled out completely. What reasons are left to account for the apparent barrenness of the universe?
A recent paper by Nick Bostrom of Oxford University postulates that some 'Great Filter' might exist, which causes lifeforms to go extinct before they can spread across the cosmos. This could be a cataclysmic event, or just a mundane limitation that stops most organisms from evolving into something complicated enough for space travel. Bostrom argues that this filter is either behind us - humanity has passed the test - or somewhere in our future - bad news. His conclusion: discovering evidence of a complex extra-terrestrial lifeform would indicate the Great Filter is waiting for us ahead, and we are as dead certain to fail at perpetuating our species as the billions of other races that must have existed throughout the galaxy before us.
The discovery of Gliese 581g is a great step in astronomy, physics, and potential science fiction topics. However, the Fermi paradox implies that if we ever go there, and discover even so much as an amoeba, it's a dismal sign for humanity's ultimate prospects of survival.
The filter, not necessarily extinction as I see it, is before us, in that we have not figured out how to travel that far and keep ourselves alive. It may happen some day, but until then, we are blocked from exploring space.
ReplyDeleteNice and interesting article.
One possibility is that all technological civilizations turn into solipsist virtual societies before they are capable of interstellar colonization.
ReplyDeleteThis would remove the need to explore when all consciousnesses could create their own wish-world, and also the need for colonization because there would not be any population pressure. Also, this would explain the dearth of signals from other civilizations..
They're just not interested in this reality, they have their own.
Blackjack raises a valid point about why potential alien civilizations wouldn't contact us. It's plausible to imagine some proportion of (hypothetical) alien civilizations turning inward, to "solipsist virtual societies." However I can't imagine that being the case for all of them.
ReplyDeleteThe sheer enormity of the universe and the incredibly long span of time involved means there should be a near-infinite number of (potential) alien species out there, who might potentially colonize many galaxies. While many could choose not to, some small fraction would... and that's still a very large (theoretical) number of outward exploring civilizations. The real-life fact that this hasn't happened must indicate there is some other barrier, or “filter” in Dr. Bostrom's terminology, preventing them from reaching that stage. Hopefully, that filter is behind us, in the early stages of sentient life's development, not ahead somewhere in the future.
In any case, I think blackjack raises an interesting point about the way societies may turn in rather than out. I'm not sure that it's enough to resolve the Fermi paradox in its entirety though.
This whole "paradox" assumes that probability = reality, which, above the realm of quantum mechanics, is purely a fallacy. Just because there has been enough time for a civilization to spread across the universe, the lack of an intergalactic civilization does not mean there is none. Every moment is the maintains the possibility, or even probability of some species somewhere in the universe beginning this expansion. The sheer size of the universe, and the relatively minuscule size of our observed realm can completely explain away the paradox. A galactic, or even intergalactic empire could just as equally exist at the edges of our collective vision as a "new" species could exist in the deeper depths of our own oceans. The lack of observation does not equate to a lack of existence.
ReplyDeleteCould also be worth noting that just because of sheer distance between us and this hypothetical life source; when looking straight at them, the likelihood is that we would be looking at that area 100m (or however many) years in the past. Thus meaning that they're entire species may only be in its ameba/primal stages.
ReplyDeleteHowever this idea gives me the shivers lol, purely because think about what that means if we saw in the far distance reaches of the universe; an already space-developed species...
Maybe we hit the technological singularity and this "reality" becomes irrelevant. Or we become infinitiely wise and don't need to conquer space.
ReplyDelete