Dark Energy Is Fast Time: Cosmic Acceleration Is Produced by the Free-Time Logistic Transport Law

Dark energy is fast time. As matter gathers into galaxies, clusters, and walls, most cosmic volume becomes increasingly empty. This paper proposes that time runs faster in those low-density regions because they contain fewer stable physical records of interaction; as voids occupy more of the universe, the effective rate of cosmic time increases, and light traveling through the evolving mixture of slow-time structures and fast-time voids produces the distance-redshift relation interpreted as accelerated expansion. The proposal yields an exact dynamical law: F_time(a) = logistic[u0 + sqrt(2) ln a], dF_time/d ln a = sqrt(2) F_time (1 - F_time) - the Free-Time Logistic Transport Law - with the environmental bridge logit(F_time) = -ln 4 + (8/5) logit(f_v), whose every constant is derived (A = 4, p = sqrt(2), B = 8*sqrt(2); gain 8/5 from a finite source-exposure law). Full-covariance public-data tests favor the fixed law over LambdaCDM at equal parameter count: DESI DR2 BAO + Pantheon+ gives Delta chi^2 = -4.73 (-6.07 at the release-standard selection); DES-SN5YR strengthens it to -9.4 to -10.1 with both information criteria favorable; DESI DR1 full-shape (including growth) gives -6.7 to -8.6; the six-channel non-distance ledger reads approximately -8.4 under every tested treatment; and the fixed law beats the two-parameter w0-wa parametrization on both information criteria with two fewer fitted degrees of freedom. The theory predicts a present jerk j0 = 1.99 (vs 1.00), positive snap s0 = +9.0, a parameter-free present void fraction f_v0 = 0.704, and a characteristic percent-level growth tilt. Every number regenerates from thirty-four embedded reproduction scripts and cited public data. Scope note (August 2026). This record develops the broader fast-time mechanism, the Free-Time Logistic Transport Law, the environmental/void bridge, and auxiliary observational tests. The dedicated reproducible DESI DR2 BAO + Pantheon+ distance analysis—and the authoritative fit, Monte Carlo calibration, robustness, and cosmographic results for that test—is published separately as Dark Energy Is a Rate, Not a Substance: Time Runs Faster in Emptier Space (doi:10.5281/zenodo.21744882). Cite that record for the distance-test statistics.