Darwin's Extraterrestrials [View all]
The Fermi paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations. As Enrico Fermi asked if the Universe is conducive to intelligent life, Where is everybody?
A new answer proposed by Adrian Kent of the University of Cambridge and Perimeter Institute, is that extraterrestial life sufficiently advanced to be capable of interstellar travel or communication must be rare, since otherwise we would have seen evidence of it by now. This in turn is sometimes taken as indirect evidence for the improbability of life evolving at all in our universe.
Intelligent species might reasonably worry about the possible dangers of self-advertisement and hence incline towards discretion -- the Undetectability Conjecture, put forth by Beatriz Gato-Rivera, a theoretical physicist at the Instituto de Fisica Fundamental (previously Instituto de Matematicas y Fisica Fundamental) of the CSIC (Spanish Scientific Research Council) in Madrid. According to Gato-Rivera, we may find ourselves in a universe in which there exist intelligent technological civilizations but they have chosen to be undetectable, camouflaging themselves mainly for security reasons (because advanced civilizations could also be aggressive).
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