Galactic Interconnection, Fluid Vortex Merging, and the "Fine-Tuning" Paradox of Dark Matter Distribution

Modern astrophysics relies on two mathematical placeholders to maintain the stability of galactic structures: the stationary Dark Matter Halo and the gravitational dominance of Supermassive Black Holes (SMBHs). This paper invalidates both assumptions through quantitative scaling and fluid dynamics. We demonstrate that the mass of Sagittarius A* ($4.3 \times 10^6 M_\odot$) constitutes a mere $0.004\%$ of the Milky Way’s visible mass, making it mathematically impossible to exert stabilizing centripetal control over stars at a distance of 70,000 light-years. Furthermore, we challenge the Dark Matter hypothesis by introducing the "Fine-Tuning Paradox": if dark matter were a stochastic, non-baryonic particle, uneven galactic distributions would cause millions of "rogue stars" to be flung into the cosmic void due to centrifugal dominance—a phenomenon heavily contradicted by observational data. Instead, we propose a macro-vortex framework within the non-vacuumable cosmic fabric. Galaxies are modeled not as isolated gravitational entities, but as local manifestations of universal fluid turbulence. Galactic arms and the seamless coalescence observed in galaxy mergers are explained via the "Fluid Injection Vortex" mechanism, mimicking ink filaments in a draining vortex. This co-moving metric resolves the mass-deficit paradox and eliminates hydrodynamic shear resistance ($\Delta V \to 0$) at galactic boundaries without altering baryonic mass profiles.