[BLOG-LIKE POSTING] More on the Fermi Paradox

[rfmcdonald]

Keith Wiley's paper on the Drake Equation seen in the context of viable self-reproducing probes and long-lasting interstellar civilizations is something I'm still thinking about. My initial reaction was reposted over at Wordpress while here at Livejournal the original sparked a good debate in the comments.

Now, mindstalk has written a post assembling links to the paper and some of the more significant commentaries, himself, suggesting that the Great Filter--if I read him correctly--has more to do with limits to the emergence of tool-using intelligences capable of eventually expanding across space (the existence of worlds sufficiently stable to support the evolution of tool-using intelligence, for starters) than with the sorts of existential threats to tool-using intelligences that might legitimately leave us worried. heron61 comments on reasons even a successful tool-using intelligence might not embark upon indefinite expansion.

Maybe technological intelligence is fairly rare and typically has one of two paths - extinction before they attain interstellar capability or becoming a massively networked collective (perhaps uploaded, perhaps not), where no one wishes to go more than (at absolute most) a light second or two beyond the main collective.

Also, if intelligence is rare (and thus, it's maybe 10,000 light years between intelligences) interstellar travel or communication as a means to meet other sentients is essentially useless.

At that point, what are the reasons for interstellar expansion? Trade in raw materials is pointless and vastly uneconomical. If other life-bearing worlds are by definition not habitable to your species (being evolved for entirely different life=forms), then the only answers are space colonies or terraforming, which you can do just as well in your homesystem.

Exploration via probes makes sense, but again, once you've gone more than 1,000 or so light years travel time + reporting back time starts getting sufficiently long that even long-lived sentients might not bother. It's going to be far easier to build non-replicating probes, and that can get you data on every potentially interesting star within a reasonable range.

Finally, I remain dubious about self-replicating probes that remain active over millennia, drifting through deep space. Too much interstellar dust and fast probes are destroyed (and if you're going 0.004 C, too much isn't very much). There's going to be a failure rare for all tech - over thousands of years, that failure rate might be fairly high. The failure rate for probes landing on planets and successfully making more probes (and propulsion for them) is likely to be even higher.

Me, I think that if there really were hundreds of billions of active self-replicating probes in our greater solar system (as Wiley suggests is a mathematical possibility, if a perplexing from the perspective of observational astronomy), we may as well have some hope. The probes haven't destroyed us yet, and who knows? Outnumbering us so significantly, with technological and material resources we of Earth can't hope to match, theirs would be the superior economy. Maybe the self-replicating probes could buy out the PIGS and so solve the sovereign debt crisis. Wouldn't it be worth making a few transmissions into the Oort Cloud to try and find out?