Foundations of Interstellar Physics and Systems Engineering: A Global-Realist Framework

We develop a mathematical-physical framework connecting finite matter, causal field response, and relativistic dynamics to the engineering of interstellar systems. The formulation begins with exponential coordinates for Lorentzian metrics, boundary-completed Einstein–matter actions, and constraint-compatible initial data. Eliminating unresolved degrees of freedom introduces retarded response kernels and preparation terms, while explicit storage functions and power-conjugate couplings describe energy and momentum exchange among matter, fields, structures, and thermal processes. These constructions support continuum and finite-state descriptions with identifiable spatial, spectral, and temporal approximation errors. The framework extends to propulsion and braking, spacecraft motion and structural response, energy conversion and heat rejection, materials and industrial processes, communication, navigation, autonomous operation, and large-scale infrastructure. Variational equations, local conservation laws, entropy production, principal symbols, mode analysis, and controlled limits connect the underlying models to engineering observables and subsystem interfaces. Stability and approximation results are stated under explicit assumptions on constitutive response, regularity, boundary conditions, and control realization. Proposed curvature- and topology-dependent extensions are distinguished from established relativistic dynamics: a metric parametrization or an effective response cone alone does not establish a realizable source, a transport mechanism, or a payload arrival advantage. Global realism supplies the finite-matter and source–response hypotheses, whereas constitutive laws and their physical identification remain explicit components of the modeling problem. This work is presented in two versions. The revised version differs substantially from the original in scope, organization, and mathematical development, and is more appropriately read as an academic monograph on the physics and engineering of an interstellar era than as a conventional research article. The original and revised versions should therefore be read comparatively to distinguish continuity of the underlying ideas from changes in formulation, assumptions, and conclusions. Keywords Global realism; interstellar physics; relativistic systems engineering; causal field response; geometric memory; continuum mechanics; spacecraft dynamics; propulsion and braking; nonequilibrium thermodynamics; communication and navigation; autonomous systems; interstellar infrastructure.