Not all useful tools for thinking must be considered science. I think it's quite fair to say the Drake equation isn't "science". However, I think Popper's "con

Not all useful tools for thinking must be considered science. I think it's quite fair to say the Drake equation isn't "science". However, I think Popper's "conjecture and refutation" is a more interesting model for thinking about the increase of knowledge than falsifiability is. Through that lens, you might say the Drake equation was a conjecture intended to stimulate refutations, which might lead to further productive theories. Popper's essays on Parmenides are really interesting on this. Popper frames Parmenides' philosophy as essentially a conjecture that "change is an illusion", and the history of western science since then as various "research programmes" in response to that. I'm summarising terribly, but I think he illustrates well the value of conjectures that aren't necessarily "scientific" in stimulating thought.