Dual-Force Coupling in Celestial System Evolution and the Steady State of Eternal Cosmos

Contemporary cosmology takes the ΛCDM standard model as its core framework. Relying on the gravitational picture of spacetime curvature described by general relativity, it attributes a series of observational phenomena—including the flatness of galactic rotation curves, cosmic expansion, and the formation of large-scale structures—to two hypothetical entities, dark matter and dark energy, which have not been directly detected by any experiments to date. Meanwhile, at the scale of the solar system and planetary systems, traditional tidal force theory is used to interpret lunar recession, tidal locking, orbital inclination variations, and other phenomena; however, it suffers from clear quantitative failures and logical inconsistencies in explaining long-distance celestial evolution and galactic-scale structure formation. With the deployment of new-generation observatories such as the James Webb Space Telescope, numerous observational facts conflicting with the conventional cosmic evolution timeline have emerged continuously: the appearance of massive, mature disk galaxies and highly regular special galaxies such as Hoag’s object within an extremely short time after the Big Bang; the long-term stability of galactic spiral arms without winding and disruption; the recession rate of the Moon that cannot be precisely reproduced by traditional tidal friction theory; and the orbital evolution rates of distant celestial bodies that strongly deviate from the decay law of gravitational differences. The common root of these contradictions is that traditional gravitational theories have consistently treated interactions between celestial bodies as purely radial, irrotational, and static single-field forces, completely ignoring the dynamic deformation of gravitational fields induced by central body rotation and the resulting equatorial tangential force component, leaving a critical dynamical structure missing from the fundamental theoretical framework. This paper presents the Hydraulic Torque Converter Cosmological Model for Galactic Dynamics, which adopts the dual-force coupling of radial universal gravitation and equatorial tangential drag as the unified core mechanism, and reconstructs a complete evolutionary theory from the Earth–Moon system, solar system, and Milky Way to cosmic large-scale structures. The model is rigorously grounded in pure gravity itself, independent of fluids, media, spacetime viscosity, or vacuum shear effects. It abandons the static interpretation of spacetime curvature in general relativity and recognizes only universal gravitation as the sole genuine long-range interaction in the universe. On this basis, the model proposes three fundamental revisions: (1) The total controlling force exerted by a central body on an orbiting body is not a single radial gravitational force, but a dual-force coupling system composed of radial binding gravity and a rotation-induced tangential deformation component of gravity; (2) Tidal force as defined in traditional theory is not an independent fundamental force, but essentially a macroscopic equivalent effect of the equatorial tangential drag acting on finite-size bodies, and traditional tidal theory is a partial, local, approximate description of dual-force coupling; (3) The rotational and orbital angular momentum of celestial bodies are not primordial properties imposed by Big Bang initial conditions, but dynamically generated a posteriori through hierarchical merging, accretion, preferential superposition of angular momentum, and directional alignment by the rotation-deformed gravitational field of central bodies, fundamentally refuting the primordial Big Bang momentum hypothesis. This work constructs a complete quantitative physical formula system and introduces the universal gravitational soft-coupling constant K, achieving an exact quantitative reproduction of the lunar recession rate of 3.8 cm/yr in the Earth–Moon system and unified predictions of orbital expansion rates for the eight planets of the solar system. Without introducing dark matter, dark energy, ad hoc parameters, or fine-tuned initial conditions, the model consistently explains a range of phenomena that have challenged traditional theories: the flatness of galactic rotation curves, rapid assembly of mature galaxies in the early universe, the perfectly ringed structure of Hoag’s object, long-lived galactic spiral arms, large-scale cosmic filamentary structures, and cosmic expansion. Within the unified dynamical framework, this paper finally derives the ultimate conclusion of cosmic evolution: all celestial systems in the universe evolve unidirectionally from a developing, unlocked state toward tidal-locked steady states. As time approaches infinity, global tangential drag torques gradually vanish, and the rotational angular velocity of every central body becomes synchronized with the orbital angular velocity of its orbiting bodies. The universe then enters an eternally stable dynamic equilibrium state with no angular momentum transfer, orbital deformation, structural disruption, uncontrolled entropy growth, or gravitational collapse—the Steady State of Eternal Cosmic Life. With minimal physical assumptions, the model achieves maximal observational coverage and is self-consistent, unified, quantifiable, and falsifiable. It provides a novel foundational framework for celestial motion, galaxy formation, cosmic evolution, and the ultimate fate of the universe. We propose a rotation-induced dual-coupling celestial dynamics model to study long-term angular momentum transport, orbital evolution, coplanarization, synchronization, and disk formation in celestial systems. Beyond conventional radial gravity, the model introduces an equatorial tangential coupling acceleration driven by the relative angular velocity difference between central body rotation and orbital motion. This formulation ensures that the tangential coupling vanishes naturally under synchronous locking and avoids tension with the equivalence principle. We first examine conservation laws and orbital evolution equations in nearby celestial systems, proposing calibration via lunar laser ranging and independent tests using satellite and planetary systems. We then discuss extensions to galactic disk angular momentum transport, spiral arm persistence, ringed galaxy formation, and early galaxy assembly. Finally, we limit cosmological applications to a future research program, noting that any claim to replace dark matter or dark energy must pass stringent observational tests including the CMB, BAO, gravitational lensing, and structure growth rates. The core contribution of this work is not to immediately replace existing cosmological models, but to present a testable, rotation-induced effective dynamical framework with well-defined dimensions, conservation relations, computable orbital equations, and falsifiable predictions.