From viability windows to generative landscapes: A conditional evidence atlas for physical possibility

A parameter region permitting several kinds of structure need not establish a common history that produces and connects them. Conversely, the failure of one familiar pathway need not exclude alternative realizations. We develop a conditional evidence atlas that preserves these distinctions when combining studies of physical possibility. Each record specifies varied and fixed quantities, target structures, physical outputs, downstream requirements, and evidential status. An audit of stellar and nuclear viability windows shows where a multidimensional extension is unsupported, without claiming that the underlying physical worlds are impossible. A matter-density calculation distinguishes two interventions that share a reduced baryon-to-photon ratio but differ in their cosmological consequences. A published weakless cloud-to-star calculation supplies a positive example of checking a transition rather than only its endpoints. A separate reversible reaction benchmark demonstrates why endpoint yield, continuous residence, and qualified formation are different readouts; changing qualification reverses a candidate ranking while leaving the physical dynamics unchanged. These cases support a two-layer atlas: source-conditioned possibilities and explicitly specified history-dependent tasks. The contribution is an auditable organization of comparative evidence, not a new theorem, probability measure over universes, or universal growth law. An incompatible combination of source assumptions is kept distinct from physical impossibility. The manuscript and accompanying documentation are licensed under CC BY 4.0. Self-authored verification code in the supplementary archive is licensed under the MIT License. Third-party rights are retained. Correspondence: [email protected].