Estimating the number of people who have
experienced the paranormal or supernatural

The Drake Equation is the famous formula developed by the astronomer Frank Drake for estimating the number of extraterrestrial civilizations:

N = R × f_p × n_e × f_l × f_i × f_c × L where…

• N = the number of communicative civilizations,
• R = the rate of formation of suitable stars,
• f_p = the fraction of those stars with planets,
• n_e = the number of earth-like planets per solar system,
• f_l = the fraction of planets with life,
• f_i = the fraction of planets with intelligent life,
• f_c = the fraction of planets with communicating technology, and
• L = the lifetime of communicating civilizations.

The equation is so ubiquitous that it has even been employed in the popular television series The Big Bang Theory for computing the number of available sex partners within a 40-mile radius of Los Angeles (5,812). My favorite parody of it is by the cartoonist Randall Munroe as one in a series of his clever science send-ups, entitled “The Flake Equation” (on xkcd.com) for calculating the number of people who will mistakenly think they had an ET encounter. (continue reading…)

The lifetime of civilizations in the Drake equation
for estimating extraterrestrial ntelligences
is greatly exaggerated

In science there is arguably no more suppositional formula than that proposed in 1961 by radio astronomer Frank Drake for estimating the number of technological civilizations that reside in our galaxy: N = R fp ne fl fi fc L

In this equation, N is the number of communicative civilizations, R is the rate of formation of suitable stars, fp is the fraction of those stars with planets, ne is the number of Earth-like planets per solar system, fl is the fraction of planets with life, fi is the fraction of planets with intelligent life, fc is the fraction of planets with communicating technology, and L is the lifetime of communicating civilizations. (continue reading…)