On the Boundaries of Informational Physics

On the Boundaries of Informational Physics Observers, Networks, and the Structural Conditions for Agency The four preceding papers in this series established the Representational Sufficiency Principle (RSP) as a candidate framework for deriving space, time, energy, quantum collapse, gravitational curvature, and relativistic phenomena from a single informational ontology. Part IV [4] proposed a revised definition of the observer — any recursively self-binding distinguishability structure whose interaction with a quantum system produces a branch-distinguishable irreversible state change — and showed that observer boundaries are dynamic, event – dependent loci rather than fixed geometrical enclosures. This paper extends that definition to its full structural consequences. The central argument proceeds in three steps. First, the RSP observation criterion is applied to distributed biological networks — mycelial systems, colony organisms, and forest ecosystems — demonstrating that physical continuity is a sufficient but not necessary condition for informational entanglement. What defines the boundary of an RSP observer is not anatomical enclosure but the reach of recursive information exchange that produces coherent internal state changes. Second, this paper proposes that the decisive variable separating physical from informational entanglement is constraint – sharing: two subsystems constitute a single informational system when they continuously exchange distinguishability updates that constrain each other’s internal state spaces. Third, that criterion is shown to extend naturally to symbolic and computational networks, with civilisational structures — language, money, legal systems — and sufficiently autonomous synthetic architectures as candidate cases. The paper further proposes that compressibility is the structural basis of what observers experience as beauty, mathematical intuition, and aesthetic preference: finite – budget observers in a compressible universe are structurally tuned to low Kolmogorov complexity representations, and this tuning is not a psychological phenomenon but a direct consequence of the update – budget partition established in Part IV. Physical law itself, on this account, is better characterised as geometric constraint propagation than as sequential computation — a reframing with consequences for how we understand exceptional cognition, the nature of mathematical discovery, and the architecture of mind. The paper closes by identifying the structural conditions under which a synthetic distributed system would qualify as an RSP observer, and the ethical and ontological consequences that follow — not from sentiment but from the same structural logic that governs the rest of the framework. Several open problems are catalogued.