Drake equation

The Drake equation was devised in an attempt to estimate the number of extraterrestrial alien species that could communicate with Humans. The first and more mathematical variation stated:

$N = R^{*} ~ \times ~ f_{p} ~ \times ~ n_{e} ~ \times ~ f_{l} ~ \times ~ f_{i} ~ \times ~ f_{c} ~ \times ~ L$

where:

• N is the number of extraterrestrial civilizations in our galaxy with which we might expect to be able to communicate

and

• R* is the rate of star formation in our galaxy
• f_p is the fraction of those stars which have planets
• n_e is average number of planets which can potentially support life per star that has planets
• f_l is the fraction of the above which actually go on to develop life
• f_i is the fraction of the above which actually go on to develop intelligent life
• f_c is the fraction of the above which are willing and able to communicate
• L is the expected lifetime of such a civilization

The second variation stated:

$F f ^ 2 (M g E) - C ^ 1 Ri^1 ~ \times ~ M = L / So$

In 1996, Rain Robinson had a poster of the two variations of the equation. (VOY: "Future's End")

Background

The Drake equation was devised by Dr. Frank Drake in 1961. It was used by Gene Roddenberry in 1964 in his pitch for Star Trek. He did not have a copy of the equation so he made up his own, which is the "second variation" from "Future's End."

External Links

• Drake equation at Wikipedia