Fermi paradox (E. Fermi): E. Fermi's inference, simplified with the phrase, "Where are they?" questioning that when the Galaxy is filled with intelligent and scientific civilizations, why haven't they come to us hitherto? There are numerous possible answers to this query, however as we only has the vaguest idea what the correct conditions for life and intelligence in our solar system, it and Fermi's paradox are no more than conjecture.