[Fitzcarraldo]

Seems like the Drake Equation should have another multiplier quantifying the fraction of civilizations that send out "artifacts", the number of said "artifacts" and the probability of their detection.

[edwin hubble]

"Seems like the Drake Equation should have another multiplier quantifying the fraction of civilizations that send out "artifacts", the number of said "artifacts" and the probability of their detection."

I see that covered by this Drake variable (my reply #18):

fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.