Fermi paradox

The Fermi paradox is the contradiction between the high estimated probability that intelligent life exists elsewhere in our galaxy and the absence of any evidence for it. It is named after the physicist Enrico Fermi, who is said to have raised the question in a casual lunchtime conversation with colleagues at Los Alamos, New Mexico. The galaxy is billions of years old and contains hundreds of billions of stars, so an advanced civilization could in theory have spread across it long ago. Proposed answers include that intelligent life is extremely rare, that civilizations destroy themselves, that interstellar travel is too hard, or that we simply have not looked hard enough. The question inspired the Drake equation and the search for extraterrestrial intelligence.

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