Nick Bostrom’s written a fascinating article about why he hopes the search for extraterrestrial life yields nothing.
Basically it comes down to the idea that if we discover the remains of some kind of life, then life is not as statistically improbable as we might like to think it is. And if it’s not that statistically improbable, then why haven’t we already been visited?
One possibility is that by the time a civilization has developed the technology to colonize space, they manage to destroy themselves first. Or eco-disaster wipes them out. Or whatever. The point is that a Great Filter lies ahead, a hurdle we’re extremely unlikely to leap over.
Of course, if we find nothing, we’ve got nothing to worry about. For now.
Anyway, it’s an interesting read.
The coolest thing in it that I’d never heard of: Von Neumann probes, a theoretical self-replicating spacecraft for colonizing the universe.
3 Comments
First of all, any prediction we make about extraterrestrial life is going to be based solely on what we know of ourselves and, therefore, limited. But I agree with much of this. I think it is the fate of intelligent life to gobble up its planet’s resources in the final triumphant exhalations of its greatness, exiling itself to it’s own temperate rock until its star finally goes nova. Intelligent life seems to require a very long ceasefire from extraterrestrial bombardment. We have a giant gas ball circling far enough away that its gravity doesn’t mess with us but close enough for it to hoover our solar system of large asteroids and comets. Then we have a sizable moon to scoop up some of the smaller ones that get through. Even so, we’ve been lucky and have taken advantage of this few million years of calm to crawl out from under the rocks and start drilling for oil.
So, I guess that intelligent life is relatively rare. Even so, why has SETI found no transmission worthy of a second look? Do we broadcast a powerful beacon to the sky? Did we forget that communication is a two-way street? Are there other listener civilizations out there wondering why the heavens are quiet while also forgetting to transmit something powerful? Can’t they see the Luxor in Vegas?
A few other things: Maybe we ARE them. 3.8 billion years ago, life sprang up here, with DNA and everything. The basic structure of DNA has not changed since. That suggests biotechnology to me, suggests colonization. If we are them, then the only question is where are the others. But if we haven’t managed to go anywhere else yet, then why should we expect them to have?
Maybe they ARE here. If we are headed for a tech-y transformation into silicon or pure information or whatever, and somebody else is even just a little bit ahead of us, then how would we recognize them? It would be like taking a Windows Vista disk and trying to read it on a Sinclair ZX-80 from 1981. Does not compute — there is nothing on the disk.
When I read stuff like this i get very excited, but also frustrated by the cultural or even species bigotry. I think we would recognize any life that was behind our development or even with it — but those forms of life aren’t going to get here yet, are they? (Unless we are them, as my first point states.) But any form of life evolved past us, especially way past us, I just don’t see why we think we would recognize it. When I go out in a field and pick up a praying mantis, look at it for a while, then put it back down, does it realize what has happened? On the other hand, maybe praying mantises are already in contact with aliens telepathically or something. How do we know they’re not?
Besides, haven’t humans described alien-type visitations pretty much since we began writing stuff down? The Bible is just one example filled with mysterious God-like visitors from cover to freaking cover, some of them, like Ezekiel’s, straight out of Hollywood. The whole of mythology is chock full of the same stuff. My overall gut feeling is that we are them, and also others of us have come here, too, or have also evolved alongside us on earth in ways we don’t understand yet (angels, devils, ghosts, leprechauns, fairies, succubi, Gods, bulb-headed aliens, etc. etc., and could well be living here in our midst. As long as they are even a little more advanced, they are safe from our detection, or at least from our present scientific instruments. This speculation fits the best with my reading of the human story so far. It’s not scientifically provable, but that doesn’t bother me.
Me too, i haven’t got the chance to stumble upon Von Neumann probes. But regarding the possibility of life out there can be something we can ponder on. The thought of having other planets and other galaxies aside than Milky Way, makes it more probable to conclude that there could be another version of Earth somewhere there. Or maybe there could be a place like AVATAR somewhere our technologies can’t reach.