>> exclusively on the presumption that an advanced civilization would emit (intentionally or as a byproduct) RF in a manner we can detect
No. That is radio SETI. The search for life also looks includes Dyson-SETI, the search for megastructures, or other technosignatures, which can have nothing to do with RF.
(1) A galaxy without any supernovas, with all the dangerous stars pushed out of the galactic disk -> the lumberjack scenario.
(2) A planet with gasses associated with industry -> technosignature.
(3) Unexplained planetary phenomena, starlight doing things that suggest large orbiting megastructures (Dyson sphere territory).
... and the list goes on. Radio telescope SETI is one very small corner in the search for other civilizations.
No. That is radio SETI. The search for life also looks includes Dyson-SETI, the search for megastructures, or other technosignatures, which can have nothing to do with RF.
(1) A galaxy without any supernovas, with all the dangerous stars pushed out of the galactic disk -> the lumberjack scenario. (2) A planet with gasses associated with industry -> technosignature. (3) Unexplained planetary phenomena, starlight doing things that suggest large orbiting megastructures (Dyson sphere territory). ... and the list goes on. Radio telescope SETI is one very small corner in the search for other civilizations.