ZIPPED: A Parameter-Free Mechanical Coupling of Light Speed and Gravitation

This manuscript presents ZIPPED (Zwanenburg Integrated Pythagorean Pressure–Expansion Dynamics), a closed, parameter-free gravitational framework in which the speed of light acts as a universal mechanical governor of spacetime tension. Through a unique and smooth Pythagorean composition of Newtonian gravity with a cosmological coupling term, the theory yields a natural, mass-dependent transition scale: the Zwanenburg Radius. This scale emerges from first principles and is independent of environment, interpolating functions, or external field corrections. ZIPPED reproduces the observed dynamical transition in Gaia wide-binary systems without empirical fitting and extends consistently to galactic rotation curves and cluster dynamics. In contrast to MOND, the transition behavior follows necessarily from the mechanical architecture rather than phenomenological adjustment. The framework predicts a slightly rising yet stable galactic rotation profile, interpreted as a dynamical equilibrium with expanding spacetime. ZIPPED offers a falsifiable, dark-matter–free alternative grounded in fundamental constants alone. Keywords (Zenodo metadata) ZIPPED theory Zwanenburg Radius Modified gravity Wide binary stars Gaia data Galactic rotation curves Parameter-free theory Light speed coupling Spacetime tension Alternative to dark matter Hashtags (Zenodo + LinkedIn bruikbaar) #ZIPPED#ModifiedGravity#GaiaMission#WideBinaries#GalacticDynamics#NoDarkMatter#TheoreticalPhysics#FundamentalConstants#SpacetimePhysics#GravityTheory