> If you enjoy probabilistic arguments, then you'll appreciate why I think that B-vN probes are inevitable. You seem to be under the impression that I wasn't f

> If you enjoy probabilistic arguments, then you'll appreciate why I think that B-vN probes are inevitable. You seem to be under the impression that I wasn't familiar with that argument, even though I explicitly described it as "the probability that any civilization will colonize the galaxy with a runaway drone program that can be easily detected". I don't think there is a person in this thread who doesn't understand the basic assumption. Your claim of inevitability only applies to an infinite amount of time, so in our universe at this point in time the number can still be (and probably is) zero. So I'm trying to talk about a more refined model instead, namely one that tries to at least reserve room for factors such as the overall number of active civilizations, and the likelihood that we actually discover a drone. To start off with, we have no idea what the probability of a single civilization colonizing the galaxy with drones even is, and we're also making a lot of implicit assumptions about the nature of these drones. The argument that "one case is enough" is valid, but still the overall likelihood of that one very specific case may be too low. There is also the possibility of drones going by undetected. We don't know what the drones' navigation algorithm would look like, but it's at least conceivable that some solar systems might have been left out altogether. Finally, I'm not sure if we could necessarily detect moderate drone activity in the outer solar system at all.