  Within the SETI community, a school of thought holds that ET might prefer to
send information physically in so-called "probes," rather than by radio or
optical beacon, in effect, a message in a bottle. In this paper, a related
solution to Fermi's Paradox (also known as the "Great Silence") is proposed
whereby ET civilizations aggregate knowledge into a system of "nodes,"
interspersed throughout the galaxy. Each node explores and serves the local
star systems, detecting through its exploration non-technological life, and
enlisting newly emergent technological civilizations, such as ourselves, into
its central system. Each node would download information to new member
civilizations and upload information from those civilizations, passing it along
to its immediately adjacent nodes, such that new information would pass through
the entire galaxy at near light speed. The most local node would not be
directly detectible by us until it signaled Earth in response to a detection of
its artificial electromagnetic (EM) leakage. This is because Earth would not be
in the narrow beam of the signal pathways between our local node and its
adjacent nodes, nor between the local node and other local civilizations, while
the spillover signal strength of far distant nodes would be too weak to be
detectable. Thus, the Great Silence of the galaxy is simply the result of the
fact that Earth is not currently situated within a communications pathway in an
otherwise well interconnected galaxy.
