Drake equationn.

Brit.

/ˈdreɪk ᵻˌkweɪʒn/, U.S.

/ˈdreɪk əˌkweɪʒən/,

/ˈdreɪk iˌkweɪʒən/

Forms: 1900s– Drake equation, 1900s– Drake's equation.

Origin: From a proper name, combined with an English element. Etymons: proper name Drake , equation n.

Etymology: < the name of Frank Donald Drake (b. 1930), U.S. astrophysicist, who formulated the equation in 1961 + equation n.

Astronomy.

An equation devised to estimate the number of extraterrestrial civilizations that may potentially be detected in our galaxy.The equation combines a number of independently estimated factors, taking the form N = R^*f_pn_ef_lf_if_cL, where R^* is the rate of star formation, n_e the number of planets per solar system capable of sustaining life, and the factors f_p, f_l, f_i, f_c, respectively, the fraction of stars with planetary systems, the fraction of suitable planets on which life appears, the fraction that develop intelligent life, and the fraction that develop an advanced civilization capable of communicating with other civilizations, and L, the length of time over which such civilizations release detectable signs of their existence into space.

ΚΠ

1964 W. Sullivan We are not Alone xvii. 264 There is no immediate way to determine the chief unknown..—that of the longevity of a technological civilisation. The other factors in Drake's equation can be assessed by experiment or observation.

1979 Nature 18 Oct. 528/1 Hart pointed out that a calculation of N by means of the so-called Drake equation is essentially impossible owing to the orders of magnitude uncertainty in many of the terms.

1997 Economist 25 Jan. 109/1 The Drake equation..was a string of unknown terms, and a slightly jokey reminder ever since of that state of the search for extra-terrestrial intelligence, or SETI.

This is a new entry (OED Third Edition, September 2002; most recently modified version published online March 2022).

单词	drake equation
释义	Drake equationn. Brit. /ˈdreɪk ᵻˌkweɪʒn/, U.S. /ˈdreɪk əˌkweɪʒən/, /ˈdreɪk iˌkweɪʒən/ Forms: 1900s– Drake equation, 1900s– Drake's equation. Origin: From a proper name, combined with an English element. Etymons: proper name Drake , equation n. Etymology: < the name of Frank Donald Drake (b. 1930), U.S. astrophysicist, who formulated the equation in 1961 + equation n. Astronomy. An equation devised to estimate the number of extraterrestrial civilizations that may potentially be detected in our galaxy.The equation combines a number of independently estimated factors, taking the form N = R^f_pn_ef_lf_if_cL, where R^ is the rate of star formation, n_e the number of planets per solar system capable of sustaining life, and the factors f_p, f_l, f_i, f_c, respectively, the fraction of stars with planetary systems, the fraction of suitable planets on which life appears, the fraction that develop intelligent life, and the fraction that develop an advanced civilization capable of communicating with other civilizations, and L, the length of time over which such civilizations release detectable signs of their existence into space. ΚΠ 1964 W. Sullivan We are not Alone xvii. 264 There is no immediate way to determine the chief unknown..—that of the longevity of a technological civilisation. The other factors in Drake's equation can be assessed by experiment or observation. 1979 Nature 18 Oct. 528/1 Hart pointed out that a calculation of N by means of the so-called Drake equation is essentially impossible owing to the orders of magnitude uncertainty in many of the terms. 1997 Economist 25 Jan. 109/1 The Drake equation..was a string of unknown terms, and a slightly jokey reminder ever since of that state of the search for extra-terrestrial intelligence, or SETI. This is a new entry (OED Third Edition, September 2002; most recently modified version published online March 2022). < n.1964
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