Return Theory (RT): Fundamental Theory of Observation

This paper presents Return Theory (RT) as a foundational framework for observation. Rather than introducing new physical dynamics or modifying established laws, RT formalizes observation itself as a constrained geometric process. Observation is modeled as a projection from a full state manifold onto an observer-accessible space. Within this framework, observability, stability, and interpretability arise as geometric properties of projection, rather than as guarantees of underlying physical simplicity or completeness. The paper distinguishes observable from structurally non-observable degrees of freedom, clarifies the intrinsic limits of instrumentation, and introduces quantitative criteria for narrative stability and coherence under data accumulation. Applications to exoplanet science and SETI are discussed as domain-level tests of observational structure, not as sources of new physical assumptions. RT reframes scientific inference by separating physical existence from observational accessibility, providing a principled account of what observation can—and cannot—reveal.