EntityQ114998390· pop 22· linked from 216 articlesdark forest hypothesisSign in to savehypothesis that alien life has not been discovered because alien civilizations are silent and very cautiousConnectionssearch for extra-terrestrial intelligenceEntityBreakthrough InitiativesEntityEarthConceptuniverseEntityInternational Standard Book NumberEntityCarl SaganEntityelectromagnetic radiationEntityJohn von NeumannEntityintelligenceEntitydigital object identifierEntityInternational Standard Serial NumberEntityBlack ForestEntitygame theoryEntityastrobiologyEntityextraterrestrial lifeEntityOCLC, Inc.EntityFermi paradoxEntityJSTOROrganizationbibcodeEntityPerseveranceEntityCategoriesAstrobiologyAstronomical controversiesAstronomical hypothesesFermi paradoxHypothesesSearch for extraterrestrial intelligence