Drake equation
SETI's guiding formula
The Drake equation is a formula devised by astronomer Frank Drake in 1961 to estimate the number of detectable extraterrestrial civilizations in the Milky Way galaxy.
It multiplies factors like the rate of star formation, the fraction of stars with planets, and the likelihood of intelligent life developing.
The equation is more a framework for thinking about the search for extraterrestrial intelligence than a calculation yielding reliable numbers, since most of its variables remain unknown.
Chance something will occur
- estimationApproximate value judgment
- uncertaintyState of being unsure
- calculationMathematical problem-solving process
- speculationUnproven theorizing or risky investment
guesswork · ranges · optimistic · pessimistic · bounds · order of magnitude · unknown · conjecture
Act of seeking
- extraterrestrialBeing from outer space
- radio telescopesInstruments detecting celestial emissions
- signalsConveyed indications
- detectionAct of finding something
monitoring · observatory · listening · frequency · narrowband · Arecibo · waterhole · false positives
Worlds orbiting other stars
- habitabilitySuitability for dwelling
- Goldilocks zoneLife-permitting stellar region
- biosignaturesDetectable signs of life
- habitable zoneRegion allowing liquid water
extremophiles · panspermia · atmospheres · liquid water · rocky planets · circumstellar
Non-Earth cognitive beings
- technologicalOf machines and systems
- spacefaringAble to traverse cosmos
- advancedFar along in development
- lifespanTotal existence duration
Life from inanimate matter
- intelligent lifeBeings with cognitive awareness
- longevityDuration of existence
- fractionPart divided by whole
- parametersDefined boundaries or constraints
factors · N · L · lifetime · estimates · assumptions · inputs · constraints
Total lack of sound
- absenceState of not being
- paradoxSeemingly absurd truth
- resolutionFormal decision or determination
- implicationsSuggested but unspoken meanings
likelihood
Chance something will occur
- estimationApproximate value judgment
- uncertaintyState of being unsure
- calculationMathematical problem-solving process
speculation · guesswork · ranges · optimistic · pessimistic · bounds · order of magnitude · unknown · conjecture · inference
search
Act of seeking
- extraterrestrialBeing from outer space
- radio telescopesInstruments detecting celestial emissions
- signalsConveyed indications
detection · monitoring · observatory · listening · frequency · narrowband · Arecibo · waterhole · false positives · technosignatures
exoplanets
Worlds orbiting other stars
- habitabilitySuitability for dwelling
- Goldilocks zoneLife-permitting stellar region
- biosignaturesDetectable signs of life
habitable zone · extremophiles · panspermia · atmospheres · liquid water · rocky planets · circumstellar
extraterrestrial intelligence
Non-Earth cognitive beings
- technologicalOf machines and systems
- spacefaringAble to traverse cosmos
- advancedFar along in development
abiogenesis
Life from inanimate matter
- intelligent lifeBeings with cognitive awareness
- longevityDuration of existence
- fractionPart divided by whole
parameters · factors · N · L · lifetime · estimates · assumptions · inputs · constraints
silence
Total lack of sound
- absenceState of not being
- paradoxSeemingly absurd truth
- resolutionFormal decision or determination
- Extraterrestrialsalien, aliens, extraterrestrial, ET, UFO
- Alien Lifeextraterrestrial life, extraterrestrial intelligence, alien intelligence, first contact, biosignatures
- Carl Saganbillions, Voyager, Cornell, extraordinary claims, cosmic ocean
- Formulaschemical formula, quadratic formula, empirical formula, area formula, volume formula
- sci-fi conceptstime travel, space exploration, faster-than-light, generation ships, multiverse
- scientific theoriesatomic theory, evolution, big bang theory, quantum theory, string theory
Drake equationmathematical proof
Logical demonstration of truth
direct evidence · scientific consensus · known quantity · certainty