Space Expands, But Matter Also Expands: One Equation, Two Limits, and the Resolution of Dark Matter, Dark Energy, and the Hubble Tension

This paper identifies a single correctionto standard cosmology that dissolves threemajor anomalies simultaneously. Standard cosmology assumes that matter doesnot expand — only space does. The Hubbleconstant H is therefore treated as the fullspatial expansion rate. In fact, matter alsoexpands, more slowly than space becausebinding forces hold it back. H²r is not thefull expansion of space; it is the differencebetween spatial expansion and matterexpansion — a residual. From this one correction: (1) Gravity and expansion are not separatephenomena. They are the near and far limitsof one equation: aₛpace = H²r + GM/Aₑff (r). Newton discovered the near limit (GM/Aₑff dominates) ; Hubble discoveredthe far limit (H²r dominates). (2) Mercury's perihelion precession (43 arcsec/century) follows from spatialcontraction alone — rₑff = r (1 + GM/rc²) — because the dynamical equation alreadyencodes time. (3) Spiral arms are individual open orbits. On a spiral arm, the increase in coordinateradius cancels the stretching correction, giving rₑff ≈ const and thereforevₜ ≈ const: a flat rotation curve withoutdark matter. Seven lighthouse propositions frame theseresults. General Relativity is recovered asthe small-scale limit. The equivalenceprinciple is derived, not postulated. The universe's large-scale structure isan inevitable Turing pattern from twoexpansion speeds with ratio ~1500.