"Speaking precisely, the Drake equation is literally meaningless, and has nothing to do with science. I take the hard view that science involves the creation of testable hypotheses. The Drake equation cannot be tested and therefore SETI is not science.Which, of course is utter drivel. Michael Crichton should have stuck to writing pop novels and not ventured into passing judgement on the validity of mathematical equations and their role in science, which he clearly did not understand.
The Drake Equation is drivel masquerading a science.
How many of the terms in the equation are knowable within three orders-of-magnitude?