The Question's Ear: A Narrative Review of SETI from Cocconi and Morrison's Nature Letter to the Haystack's Measurement

Abstract

SETI---the search for extraterrestrial intelligence whose instrument is the radio telescope and whose subject is the universe's others---moved from Cocconi and Morrison's 1959 Nature letter and Drake's Project Ozma through Kardashev's civilizations, Dyson's spheres, the Cyclops blueprint, and Sagan and Drake's Scientific American to Tarter's review, Vakoch's communication, Siemion's Kepler survey, Wright's WISE search and haystack, and Frank and Sullivan's empirical constraint. This article presents a narrative review of that arc's canonical line: Cocconi and Morrison's 1959 searching, Dyson's 1960 artificial sources, Drake's 1961 Project Ozma, Kardashev's 1964 transmissions, Oliver and Billingham's 1973 Project Cyclops, Sagan and Drake's 1975 Scientific American, Tarter's 2001 Annual Review, Vakoch's 2011 communication volume, Siemion and colleagues's 2013 Kepler survey, Wright and colleagues's 2016 large energy supplies, Frank and Sullivan's 2016 empirical constraint, and Wright and colleagues's 2018 haystack. The review is organized around three themes: the question's scientific founding, in which the Nature letter's frequency, the Ozma's listening, the civilizations's types, and the spheres's infrareds made the question scientific; the programs' blueprints, in which the Cyclops's design, the Scientific American's summary, and the review's systematization built the field's plans; and the modern searches, in which the communication's, the Kepler's narrowbands, the large energy's supplies, the empirical's constraint, and the haystack's measurement carried the search into the twenty-first century's scales. It is concluded that SETI is the universe's longest question---and that its arc is the listening's persistence from the one-star's wager to the multi-million's stars.