Fermi paradox
Where is everybody?
The Fermi paradox names the apparent contradiction between the high probability of extraterrestrial civilizations existing and the complete absence of evidence for them.
Given the age and size of the universe, intelligent life should have emerged countless times and left detectable traces—yet we observe nothing.
Named for physicist Enrico Fermi, who reportedly asked "Where is everybody?" The paradox has spawned numerous proposed explanations: perhaps civilizations destroy themselves, perhaps they're avoiding us, perhaps interstellar travel is simply impossible.
Broadcast electromagnetic wave
- transmissionSending of information
- SETIQuest for cosmic signals
- contactCommunication or physical touch
- detectionAct of finding something
electromagnetic · Arecibo · listening · broadcast · beacon · wavelength · decode
Being from outer space
- SETIQuest for cosmic signals
- dark forestLightless area of trees
- biosignatureEvidence of living processes
- exobiologyStudy of cosmic life
abiogenesis · habitable zone · exoplanet · panspermia · extremophile · microbial life · Goldilocks zone
Government controlling many star systems
- interstellarBetween celestial bodies
- spacefaringAble to traverse cosmos
- colonizationForeign territorial takeover
- Dyson sphereStar-encasing energy collector
megastructure · self-replicating · expansion · settlement · technological · superintelligence · starship · generation ship
Region light has reached us from
- cosmic scaleUniverse-sized frame of reference
- light-yearsUnits of astronomical distance
- galaxyGravitationally bound stellar mass
- Milky WayGalaxy containing Earth
Perplexing problem or question
- puzzleChallenge testing ingenuity
- mysterySomething unexplained or unknown
- enigmaSomething hard to fathom
- riddlePuzzling question to solve
contradiction · question · anomaly · perplexity · bewilderment · speculation · inquiry · dilemma
Chance something will occur
- statisticsCollected numerical information
- estimationApproximate value judgment
- expectationBelief about future outcomes
- calculationMathematical problem-solving process
odds · Bayesian · uncertainty · variables · parameters · assumptions · prevalence · frequency
radio signal
Broadcast electromagnetic wave
- transmissionSending of information
- SETIQuest for cosmic signals
- contactCommunication or physical touch
detection · electromagnetic · Arecibo · listening · broadcast · beacon · wavelength · decode
extraterrestrial
Being from outer space
- SETIQuest for cosmic signals
- dark forestLightless area of trees
- biosignatureEvidence of living processes
exobiology · abiogenesis · habitable zone · exoplanet · panspermia · extremophile · microbial life · Goldilocks zone
galactic empire
Government controlling many star systems
- interstellarBetween celestial bodies
- spacefaringAble to traverse cosmos
- colonizationForeign territorial takeover
Dyson sphere · megastructure · self-replicating · expansion · settlement · technological · superintelligence · starship · generation ship · faster-than-light
observable universe
Region light has reached us from
- cosmic scaleUniverse-sized frame of reference
- light-yearsUnits of astronomical distance
- galaxyGravitationally bound stellar mass
conundrum
Perplexing problem or question
- puzzleChallenge testing ingenuity
- mysterySomething unexplained or unknown
- enigmaSomething hard to fathom
riddle · contradiction · question · anomaly · perplexity · bewilderment · speculation · inquiry · dilemma · unknown
likelihood
Chance something will occur
- statisticsCollected numerical information
- estimationApproximate value judgment
- expectationBelief about future outcomes
calculation · odds · Bayesian · uncertainty · variables · parameters · assumptions · prevalence · frequency · sample size
- Extraterrestrialsalien, aliens, extraterrestrial, ET, UFO
- Alien Lifeextraterrestrial life, extraterrestrial intelligence, alien intelligence, first contact, biosignatures
- paradoxescatch-22, Zeno's paradox, Zeno's paradoxes, causal loop, bootstrap paradox
- mysteriesmystery, enigma, enigmas, puzzle, riddle
- cosmologybig bang, Big Bang, big bang theory, universe, dark matter
- sci-fi conceptstime travel, space exploration, faster-than-light, generation ships, multiverse
Fermi paradoxfirst contact
Humanity's alien introduction
close encounter · disclosure · alien abduction · ancient astronauts · panspermia