Sunday, August 12, 2007

Resolution of the Fermi Paradox?

The Fermi Paradox is about the missing aliens. I don't remember the exact form in which Fermi presented it, so I'll begin by presenting my own form of the paradox.

Given our current technology, we could build a radio beacon that could easily be detected anywhere in our galaxy with similar technology. The Milky Way is roughly 100,000 light years across, so if we had evolved to become a stable civilization and maintained such a beacon for that long (which is trivial on the geologic time scale), then the signal would then be present everywhere in the galaxy. Now consider that there are a very large number of stars where intelligent life could have appeared, and assume that intelligence has appeared some number of times in the past. If any one of those civilizations established radio communications with another civilization and benefited thereby, then creating such a radio beacon would be the natural expression of gratitude. However, we've been looking for such beacons for a while, and we have found nothing. Why not?

There seem to be two cases for the radio silence. One would be competitive, basically a negative basis. This is predicated on intelligent animals being no better than vicious animals, but with better technology to produce sharper claws. This scenario would result in cancerous expansion of each civilization, with interstellar wars whenever they meet, and possibly even an eventual victor that would occupy the entire galaxy. Basically it comes down to any rate of geometric expansion extended over geologic time. The galaxy would be overstuffed with the first successful competitor, and any new threats would be dealt with. It is possible that our galaxy is in this state. In that case the dominant civilization would maintain radio silence for defensive purposes, but it would also aggressively and continuously search for any new threats--and exterminate them as quickly as possible. If that is the situation, then they would have spotted us long ago. Actually, they would surely track any planets that had even developed life, and most likely they would have taken possession of anything valuable long ago. Competitive geometric growth will eventually demand all of the available resources, even the marginal ones.

The other case is beyond competition, but requires that intelligence eventually evolves to the point where civilizations do become better than animals with bigger claws. This might be an inevitable result if any civilization is to avoid destroying itself. One obvious conclusion is that growth must be controlled. However, in that post-competition case, why not build the radio beacons and chat with the neighbors? I hypothesize that it's because such a civilization would be interested in knowledge, and probably in art, and the unique forms of creativity would be the most important and most valuable things. For example, though physics itself is universal, the forms of the solutions will differ, and those different perspectives have values in themselves. The explorations of the abstract mathematical mindscape can diverge even more widely into that infinity of possibilities. The art part is more speculative, because the aesthetics are so highly relative, but they will definitely be unique to each civilization--unless too much communication results in an interstellar goulash. In this scenario, the radio silence is a convention to allow for and even maximize independent evolution--but much of the resulting 'value' would be in watching how each of the unique experiments in evolution and civilization turns out. If there is such an interstellar civilization out there, it's nice to imagine that they've been tracking things all along. My personal fantasy would be that they copied the contents of the library at Alexandria and still possess such creative artifacts as the lost works of Aristotle... It makes me think of Heinlein's story about the art critic, though he seemed to be mostly devoted to the competitive scenario.

Then again, maybe we've simply been listening on the wrong channels? Doesn't seem very likely, but many things are possible, even in the finite real world.