<p>IMO the Drake Equation is an epic example of saying nothing in an intelligent sounding way. there’s no data to support any of the assumptions between “number of stars” and “number of contactable civilzations”.</p>
<p>AFAIK, out of the 200 Billion or so stars in our Galaxy, we know of less than 500 planets. Of the planets we know of, only one (1) is known to be able to support life. Only a couple of the others are even in the “maybe” category.</p>
<p>One planets that can support life, only one (1) actually has life, as far as we know. Anyone with a little knowledge of statistics will tell you that this is far to small a sample to provide any useful information about the odds of life developing.</p>
<p>Ditto for intelligent life.</p>
<p>Ditto for technology level.</p>
<p>As for the amount of time intelligent technologically advanced life survives, we do not as yet have a single measurement of this value.</p>
<p>When you add up all the unknowns, and apply statistics, you find that the margin of error is so huge that the equation provides nothing useful.</p>
<p>Not to mention that all this assumes that life develops randomly through evolution, which is a dubious claim itself (see other threads :P).</p>
<p>If, on the other hand, naturalistic evolution is false, and there is some sort of creator involved, then the number of alien civilizations depends entirely on this creator’s whim, and there is absolutely no way for us to know besides going and looking.</p>