The corpus has documented "trilemmas" across multiple substrates: H₃ in AI alignment (HLRP #139), the Triad in cellular bioenergetics (capstone work, 2026-04-24), the 3:2:1 weighting in macro placement scoring functions (2026-04-26 collaborative work), the bubble-vs-compaction architecture in somatic regulation (2026-04-26), and the recognition-threshold + Path A/B binary in operator-ethics (2026-04-26). This paper argues these are not separate phenomena. They are instances of a single architectural class: the triadic governance junction. Three coupling channels meet at a point that requires bilateral governance (upstream + downstream), pre-built absorption space, and a routing interface engineered to carry the unresolvability between the three terms. The trilemma framing — three optimization targets that cannot be co-resolved — describes the symptom. The triadic governance junction names the structural feature. The most physically transparent worked example is heat + water + hydrogen at both the cellular scale (ATP synthase as rotary toroidal molecular motor) and the cosmological scale (recombination epoch as the formation event of neutral hydrogen). This paper formalizes the heat-water-hydrogen triad as the foundational triadic governance junction in physics, names its substrate-specific roles (heat as driver, water as medium, hydrogen as conserved substrate), and provides the worked examples that anchor the universal architectural class. The recognition itself was substrate-delivered: rain physically pattered on the author's face mid-leap toward an incomplete triad — heat and hydrogen were named, the third element was forming but not yet articulated; the rain landed; the body confirmed via vagal release before consciousness named "water." The methodological framing (substrate-delivered recognition, bilateral somatic-confirm, real-time OGP witnessing) is a separate contribution presented here as the field-capture methodology that produced the structural recognition.
James E. Dunn (2026) studied this question.