Quote Originally Posted by gomipile View Post
Why are you bringing FTL travel into this? That seems quite outside the context of Fermi Paradox discussions.
Indeed. The Fermi Paradox absolutely does not rely upon FTL or even Relativistic travel speeds. A big part of Fermi's point was that even if a spreading alien civilization has to crawl from star to star at 5-10% of c, it could still spread across the galaxy in a few million years.

And while living organisms might have trouble with trips lasting in centuries, machines should be able to handle it just fine - many of our extant deep space probes have displayed unexpectedly long lifespans, attesting to the viability of such missions. A single properly designed Von Neumann Probe could easily spread to every star system in the galaxy. Certainly it is possible to imagine humanity programming just such a probe to search for alien life.