Dark Matter as Temporal Displacement in Five-Dimensional Hydrodynamic Spacetime

We develop the cosmological and particle physics implications of the five-dimensional hydrodynamic spacetime framework established in Papers I and II. First, we present a novel interpretation of dark matter as ordinary matter temporally displaced from our "present." Gravity operates across all w-positions (as the w-landscape is a global property of spacetime), while electromagnetic interaction requires shared temporal coordinates for photon exchange. The observed visible-to-total matter ratio ( 15.6%) is reproduced by a Gaussian temporal displacement distribution with σ_t ≈ 5τ_e, consistent with Big Bang nucleosynthesis constraints. This framework predicts that dark matter direct detection experiments will never succeed. Second, we show that the four fundamental forces emerge as different aspects of a single field—the w-field (time density): electromagnetism as w-t vortex radiation, the strong force as w-spatial vortex confinement, gravity as the w-landscape created by drawing costs, and the weak force as w-fluctuations that change particle type. Color charge originates from three w-spatial rotation planes, gluons are reinterpreted as emergent effects of quark binding structures, and the strong CP problem is resolved by the intrinsic w → -w symmetry of the theory. Matter-antimatter asymmetry follows naturally from the separation into positive (w > 0) and negative (w < 0) universes. Third, we develop a geometric interpretation of lepton generations based on the addition of independent w-spatial orbital planes, with three generations arising from three spatial dimensions. Mass hierarchy ratios remain an open quantitative problem, but the Koide formula 2/3 = Re/(Re+1) suggests a connection to the universal Reynolds number. Fourth, the same planar-orbit structure fixes the neutrino sector: the lightest neutrino is exactly massless (m_1 = 0, normal ordering), the heaviest satisfies m_3 = (m_μ/m_e) k_B T_CMB = 0.0486 eV (3% agreement with the atmospheric scale), and the cosmological mass sum is pinned at the normal-ordering minimum, Σm_ν = 0.057 eV (0.059 eV when evaluated with the measured splittings)—directly at the edge of current DESI+CMB bounds, making this the framework's sharpest near-term observational test. The mixing matrix is likewise fixed by structure: an approximately flavor-equal eigenstate together with an exact exchange symmetry of the two planes transverse to the propagation direction forces tribimaximal mixing at zeroth order; the exactly protected massless column then reduces all deviation to a single complex parameter—the universe's handedness—yielding the exact TM1 solar-angle sum rule sin²θ_12 = 0.318 (0.9σ; JUNO-testable) and an exact correlation between the CP phase and the atmospheric octant (DUNE/Hyper-Kamiokande-testable). The same machinery derives the smallness of quark mixing as a structural dichotomy: quark flavor labels carry no symmetry, so their zero-information skeleton is the identity matrix and no exact CKM sum rules exist.