Relative Stretching of Space and Time: 4-Dimensional Elastic Volume Conservation, Bimetallic Curvature, and Cosmic Circulation in Parallel Painlev´e–Gullstrand Fluid

The most fundamental ontological bottleneck that modern theoretical physics has failed to overcome for nearly 150 years is the artificial axiom of Minkowski spacetime geometry, which posits time as strictly orthogonal to space. This work completely rejects the assumption that space and time are independent and mutually orthogonal axes. Instead, it constructs a hydrodynamic differential geometry in which time lies parallel along the spatial flow direction, and the total 4-dimensional existence volume is strictly conserved (incom-pressibility principle, ∆Ω 4 = const.). Grounded in the Painlev´e–Gullstrand acoustic river metric, space and time are treated as two flow layers bonded at the fundamental interface (a bimetallic analogue). Gravitational curvature is derived endogenously from the differential strain gradient generated by the velocity mismatch between the spatial river flow and the local tick rate of time, without invoking an external force or an abstract field. Matter and the quantum wave function are explained through the mechanics of a “constricted, two-lobed balloon”: when the spatial lobe of the 4-volume is compressed, existence does not vanish; it bursts directly into the time and phase axis. Breathing continuously within the undulating river of time even in empty space, this balloon completely sheds its spatial lobe under extreme compression at the black hole horizon and dissolves into pure null-geodesic fibers of light. Across the non-orientable topology of a Klein 4-manifold, one end of this temporal oscillation connects directly to the primal expansion nozzles of the universe (t = 0 / White Wall). Consequently, singularities, the information paradox, cosmic inflation, and dark matter conjectures are eliminated; the universe attains a singularity-free, cyclic, and self-sustaining dynamic 4-fluid circuit.