Extraterrestrial Life & the Fermi Paradox
Von Neumann Probe Argument
Argues that a single spacefaring civilization equipped with self-replicating probes could colonize the entire galaxy within a few million years — a cosmic eyeblink — making the total absence of any such probes a strong argument against an older advanced civilization ever having arisen in our galaxy.
Proponents
Frank Tipler, building on John von Neumann's theory of self-replicating machines
Evidence For
The underlying engineering math — colonization timescales versus the age of the galaxy — is straightforward and widely accepted.
Evidence Against
Assumes any advanced civilization would choose to expand indefinitely via such probes and would never suffer a Great-Filter-style collapse first, both of which are unproven assumptions about alien motivation and longevity.
Real Sources
Transmissions
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