Defense Intelligence Reference Document An Introduction To The Statistical Drake Equation

This Defense Intelligence Agency reference document, dated 11 March 2010, is one of the advanced technology reports produced in FY 2009 under the Advanced Aerospace Weapon System Applications (AAWSA) program. It introduces the Statistical Drake Equation, which replaces each factor of Frank Drake's 1961 equation with a uniform random variable to estimate how far away the nearest extraterrestrial civilization is. In the worked example, there is a 75% probability that the nearest civilization lies between 1,361 and 3,979 light years from Earth.

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Unfortunately, to extend the Drake equation to Statistics, it was necessary to use a
mathematical apparatus that is more sophisticated than just the simple product of
seven numbers.
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