Abstract
The Drake Equation, a method for estimating the number of communicative civilizations in our galaxy, was a product of its time in several important ways. After a period of several decades during which the idea of life on other planets had reached a low point due to rise of the rare collision hypothesis for planet formation, by the 1950s the nebular hypothesis was once again in favor, whereby planets would form as a common byproduct of stellar evolution. The Miller-Urey experiments in the early 1950s produced complex organic molecules under simulated primitive Earth conditions, indicating life might easily originate given the proper conditions. And while little was known about the gap between primitive life and intelligent life, and a sophisticated understanding of intelligence was lacking, the Lowellian Mars still lingered in the cultural background and, along with contemporary astronomical advances, stimulated consideration of aliens in the scientific imagination. The original emphasis on “radio communicative” reflected the new era of radio astronomy, exemplified by the radio telescopes under construction at the newly founded National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, where Frank Drake was working. Drake’s ability to undertake such a controversial subject, including the first radio search for extraterrestrial intelligence in 1960, was aided by senior scientists Lloyd Berkner and Otto Struve. Assessments of the probabilities of extraterrestrial life and intelligence had been sporadically undertaken in the course of the twentieth century, but most particularly by former Harvard Observatory Director Harlow Shapley in his book Of Stars and Men (1958); Drake had recently graduated from the Harvard astronomy program and had cited the book. Here we look at the origins and development of the equation over time, including its significant variations; examine positive and negative views of its epistemological status and utility ranging from scientists to popular authors such as Michael Crichton; and attempt to tease out the scientific and metaphysical assumptions behind the equation. We conclude by discussing the future of the equation, and the cultural hopes and fears it embodies.
First published as the Introduction to The Drake Equation : Estimating the Prevalence of Extraterrestrial Life Through the Ages, Douglas Vakoch and Matthew Dowd, eds. (Cambridge University Press: Cambridge, 2015), pp. 1–20.
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References
Bracewell, Ronald. 1960. “Communications from Superior Galactic Communities,” Nature, 186, 670, reprinted in Cameron (1963a), 243–248
Briggs, William M. 2008. “Michael Crichton and SETI,” online at http://wmbriggs.com/blog/?p=249
Brin, David. 1983. “The ‘Great Silence’: The Controversy Concerning Extraterrestrial Intelligent Life,” QJRAS, 24, 283–309.
Burchell, Mark J. 2006. “W(h)ither the Drake Equation,” IJA, 5, 243–250.
Cameron, A. G. W. 1963a. Interstellar Communication. New York, W. A. Benjamin.
Cameron, A. G. W. 1963b. “Future Research on Interstellar Communication,” in Cameron (1963a), 309–315.
Cameron, A. G. W. 1963c. “Communicating with Intelligent Life on Other Worlds, Sky and Telescope (Nov, 1963), 258–261.
Ćirković, Milan. 2004. “On the Temporal Aspect of the Drake Equation and SETI,” Astrobiology, 4, 225–231.
Cocconi, Giuseppe and Philip Morrison. 1959. “Searching for Interstellar Communications.” Nature 184 (4690):844–846.
Crichton, Michael. 2003. “Aliens Cause Global Warming,” https://stephenschneider.stanford.edu/Publications/PDF_Papers/Crichton2003.pdf
Denning, Kathryn. 2011. “L on Earth,” in Vakoch (2011), 74–83
Dick, Steven J. 1996. The Biological Universe: The Twentieth Century Extraterrestrial Life Debate and the Limits of Science. Cambridge: Cambridge University Press.
Dick, Steven J. 1998. Life on Other Worlds. Cambridge: Cambridge University Press.
Dick, Steven J. 2003. “Cultural evolution, the postbiological universe and SETI,” International Journal of Astrobiology, 2: 65–74; reprinted as “Bringing culture to cosmos: The postbiological universe,” in Dick and Lupisella (2009), pp. 463–488.
Dick, Steven J. 2013. Congressional testimony before U. S. House Committee on Science, online at https://science.house.gov/hearing/full-committee-hearing-astrobiology-search-biosignatures-our-solar-system-and-beyond
Dick, Steven J. and Mark Lupisella. 2009. Cosmos and Culture: Cultural Evolution in a Cosmic Context. Washington, NASA SP-2009-4802.
Drake, Frank, 1959. “How Can We Detect Radio Transmissions from Distant Planetary Systems?,” Sky and Telescope, 19, 140, reprinted in Cameron (1963), pp. 165–175.
Drake, Frank, 1961a. PSW lecture in Smithsonian Institution archives
Drake, Frank, 1961b. Drake to Pearman, March 13, 1961, NAS-NRC Archives: SSB Records Group: ADM: C&B: SSB: Conferences: Extraterrestrial Intelligent Life: Green Bank (West Virginia): 1961–1962.
Drake, Frank. 1965. “The Radio Search for Intelligent Extraterrestrial Life,” in Current Aspects of Exobiology, ed., G. Mamikunian and M. H. Briggs. Oxford, 323–345.
Drake, Frank. 1992. Oral History Interview by Steven Dick, May 29 and May 30, 1992. p. 17 (NASA HQ History Office).
Drake, Frank. 2013. “Reflections on the Equation.” International Journal of Astrobiology, Special Issue on the Drake Equation, 12, 3, 173–176.
Drake, Frank. 2014a. Drake to Steven J. Dick, private communication, March 6, 2014.
Drake, Frank. 2014b. Drake to Dick, private communication, March 10, 2014
Drake, Frank. 2014c. Drake to Dick, private communication, March 17, 2014.
Drake, Frank and Dava Sobel. 1992. Is Anyone Out There? New York. Delacorte Press.
Dvorsky, George. 2007. “The Drake Equation is Obsolete,” online at http://www.sentientdevelopments.com/2007/05/drake-equation-is-obsolete.html
Dyson, F. 1966. “The Search for Extraterrestrial Technology.” In Perspectives in Modern Physics, ed. R. E. Marshak, 641–55. New York: Interscience Publishers.
Goldsmith, Donald. 1980. The Quest for Extraterrestrial Life. Mill Valley, CA.
Gonzalez, Guillermo, Donald Brownlee, and Peter Ward. 2001. “The Galactic Habitable Zone: Galactic Chemical Evolution,” Icarus, 152, 185–200.
Hart, Michael. 1975. “An Explanation for the Absence of Extraterrestrial Life on Earth,” QJRAS. 16. 128–135, reprinted in Goldsmith (1980).
Hetesi, Zsolt and Zsolt Regaly. 2006. “A New Interpretation of the Drake Equation,” JBIS, 59, 11–14
International Journal of Astrobiology. 2013. Special Issue on the Drake Equation, 12, 3.
Kreifeldt, J. G.. 1971. “A Formulation for the Number of Communicative Civilizations in the Galaxy,” Icarus, 14, 419–430.
Larson, R. and V. Bromm. 2003. “The First Stars in the Universe,” Scientific American, 285, 64–71.
Lederberg, Joshua. 1961. Lederberg to Pearman, April 11, 1961. NAS-NRC Archives: SSB Records Group: ADM: C&B: SSB: Conferences: Extraterrestrial Intelligent Life: Green Bank (West Virginia): 1961–1962.
Lemonick, Michael D. 2014. “The First Starlight,” Scientific American, 310 (April), 38–45.
Lineweaver, C. H., Y. Fenner, and B. K. Gibson. 2004. ‘The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way,” Science, 303, 59–62.
Maccone, Claudio. 2010. “The Statistical Drake Equation,” Acta Astronautica, 67, 1366–1383.
Morrison, Philip. 1962. “Interstellar Communication,” Bulletin of the Philosophical Society of Washington, 16, 58, reprinted in Cameron, 1963a, 249–271.
Oliver, B. M. 1971. Project Cyclops: A Design Study of a System for Detecting Extraterrestrial Intelligent Life. NASA Ames, Moffett Field, CA.
Pearman, J. P. T. 1961. Pearman to O. G. Villard, Jr., Dept. of Engineering, Stanford University, NAS-NRC Archives: SSB Records Group: ADM: C&B: SSB: Conferences: Extraterrestrial Intelligent Life: Green Bank (West Virginia): 1961–1962.
Pearman, J.P. T. 196. “Extraterrestrial Intelligent Life and Interstellar Communication: An Informal Discussion,” in Cameron, 1963.
Sagan, Carl. 1963. “Direct contact Among Galactic Civilizations by Relativistic Interstellar Spaceflight,” Planetary and Space Science, 11, 485, reprinted in Goldsmith (1980), pp. 205–213
Sagan, Carl, ed. 1973. Communication with Extraterrestrial Intelligence (CETI) Cambridge, Mass.: MIT Press.
Seager, Sara. 2013. “An Equation to Estimate the Probability of Identifying An Inhabited World Within the Next Decade,” online at http://www.cfa.harvard.edu/events/2013/postkepler/Exoplanets_in_the_Post_Kepler_Era/Program_files/Seager.pdf
Shapley, Harlow. 1958. “An Inquiry Concerning Other Worlds,” Of Stars and Men, Boston: Beacon Press. pp. 53–75
Shklovskii, I. S. and Sagan, C. 1966. Intelligent Life in the Universe, Holden-Day, San Francisco.
Shostak, Seth. 2009. “The Value of ‘L’ and the Cosmic Bottleneck,” in Dick and Lupisella, Cosmos and Culture, pp. 399–414.
Sullivan, Walter. 1964. We Are Not Alone. New York.
Vakoch, Douglas. 2014. Extraterrestrial Altruism: Evolution and Ethics in the Cosmos. Berlin: Springer.
Wallenhorst S. G. 1981. “The Drake Equation Reexamined,” QJRAS, 22, 380.
Walters, C., R. A. Hoover and R. K. Kotra. 1980. “Interstellar Colonization: A New Parameter for the Drake Equation?” Icarus 41, 193–197.
Ward, Peter and Donald Brownlee. 2000. Rare Earth: Why Complex Life is Uncommon in the Universe.
Zaitsev, A. 2005. “Messaging to Extra-Terrestrial Intelligence”, http://arxiv.org/abs/physics/0610031
Acknowledgments
I am thankful to the ever-helpful archivists at the National Academy of Sciences, the National Radio Astronomy Observatory, the Smithsonian Institution and the Library of Congress (Carl Sagan papers) for locating relevant documents at their institutions. I am grateful to David H. DeVorkin for comments on the paper, and to Ken Kellermann for consultation on the origin of the Drake Equation.
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Dick, S.J. (2020). The Drake Equation in Context. In: Space, Time, and Aliens. Springer, Cham. https://doi.org/10.1007/978-3-030-41614-0_7
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