Complexity mathematics was founded in the late nineteenth century to classify all nonlinear systems by their geometric architecture. For forty years, the field narrowed its focus to a single equation family, leaving the classification of multidimensional nonlinear coupled systems unperformed. The MESA Method recovered the original program and was applied to nineteen equation systems across general relativity, particle physics, fluid dynamics, statistical mechanics, astrophysics, and biology, with zero refutations. Empirical confirmation was obtained via the European Space Agency Gaia Data Release 3 stellar catalog, where Feigenbaum sub-harmonic analysis of 5, 000 stars revealed dual-attractor basin structure at p = 1. 20 x 10^-54, subsequently confirmed with 50, 000 stars at p below machine precision. A six-test falsification protocol was designed and executed to determine whether these universal results constitute a law of nature. The protocol included negative controls, constructed counterexample attempts, nonlinearity threshold sweeps, blind predictions, coupling topology comparisons, and dimensionality tests. Results: the Universal Cascade Law (UCL) states that nonlinear coupled systems with unbounded extreme-range behavior exhibit geometric organization on a continuous spectrum, modulated by coupling mode and equation content, organized in self-similar dual-attractor architecture at every level. The law is self-grounding: applied to the space of all systems it governs, it reproduces its own structure. This is the first proposed universal law of geometric organization across all scientific domains described by qualifying mathematical systems. Keywords: Universal Cascade Law; fractal geometry; nonlinear dynamics; complexity mathematics; MESA Method; Feigenbaum universality; dual attractor basins; self-grounding law; geometric organization; Gaia DR3; falsification protocol; Resonance Theory Notes: First paper of the Universal Cascade Law Trilogy. Companion papers: "The Geometric Necessity of Feigenbaum's Constant: A Derivation from the Universal Cascade Theorem" and "The Full Extent of the Universal Cascade Law: From the Origin of the Universe to the Architecture of Reality. " All computational code publicly available. All results reproducible.
Lucian Randolph (Sat,) studied this question.