Paper2011
The Search for Extra-terrestrial Intelligence
Frank Drake
The equation's author revisits it fifty years on, arguing that each term has moved from pure guesswork toward a measurable quantity as exoplanet and biosignature data accumulate.
Astronomy & Space Science · Astrobiology
The Drake Equation
A topic within Astrobiology, itself one of 9 topics in that field and part of Astronomy & Space Science.
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The Search for Extra-terrestrial Intelligence
Frank Drake · 2011
The equation's author revisits it fifty years on, arguing that each term has moved from pure guesswork toward a measurable quantity as exoplanet and…
Then
Assumes you know the vocabulary.
The Drake Equation at 60: Reconsidered and Abandoned
John Gertz · 2021
Argues most of the Drake equation's seven terms can no longer be defended even as placeholders and should be collapsed into a single honest unknown —…
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Primary sources and full treatments.
A New Empirical Constraint on the Prevalence of Technological Species in the Universe
Adam Frank & Woodruff Sullivan · 2016
Uses measured exoplanet occurrence rates to show that even a vanishingly small chance of a technological species evolving per habitable planet still…
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Paper2021
The Drake Equation at 60: Reconsidered and Abandoned
John Gertz
Argues most of the Drake equation's seven terms can no longer be defended even as placeholders and should be collapsed into a single honest unknown — the fraction of technological civilisations we could ever actually detect.
link checked 17 Sept 2026FreeIntermediate
Paper2016
A New Empirical Constraint on the Prevalence of Technological Species in the Universe
Adam Frank & Woodruff Sullivan
Uses measured exoplanet occurrence rates to show that even a vanishingly small chance of a technological species evolving per habitable planet still implies humanity was very unlikely to be the only one ever, reframing the pessimism the Drake equation usually invites.
link checked 17 Sept 2026FreeAdvanced