|Ragnar's Aliens Weeb Site|
|The Drake Equation|
The Drake Equation gives a means for estimating how many communicating civilizations may be out there. The results can vary widely, depending on the optimism of the numbers you yourself plug in.
The equation computes N: the potential number of communicative intelligent civilizations in our galaxy. It is computed using the following equation...
|N = R* x fs x fp x ne x fl x fi x fc x L|
|...using the following factors:|
|R*||is the rate of formation of stars in the galaxy|
|fs||is the fraction of stars that are suitable suns for planetary systems|
|fp||is the fraction of those stars with planets (thought to be around 1/2)|
|ne||is the number of "earths" per planetary system -- planets suitable for liquid water|
|fl||is the fraction of those planets where life develops|
|fi||is the fraction of planets with life where intelligence develops|
|fc||is the fraction of those planets that achieve technology which releases detectable signals into space|
|L||is the lifetime of such communicative civilizations|
Depending on the numbers used, the Drake equation can yield wildly differing results. Possibilities range from a few (relatively) short-lived technological civilizations scattered far apart among the stars, never contacting each other before they disappear, to a more probable (considering the vastness of the cosmos) large number of life-bearing planets. There are over 400 billion stars in our galaxy alone, and it is estimated that approximately 1/2 of all suitable suns have planetary systems of some sort.
It is not known how likely it is for life to develop on a suitable planet. Once life does exist, however, it is quite evident from our own evolutionary history that it is quite adaptable and tenacious. The jury is still out, however, on how long species survive once they have developed intelligence and powerful technology.
For more on the Drake Equation: SETI
Plug in your own numbers in this
Drake Equation Calculator.
| © Ragnar Torfason|
2005 December 28