Gravity as Manifold Compression Gradient: Deriving General Relativity, Schwarzschild Metric, and Newton's Law from Substrate Pressure Dynamics This paper is a constituent derivation of the Cymatic K-Space Mechanics (CKS) framework—an axiomatic model that derives the entirety of known physics from a discrete 2D hexagonal lattice in momentum space, operating with zero adjustable parameters. Abstract We prove that gravity—traditionally described by Einstein's general relativity as spacetime curvature or by quantum approaches via graviton exchange—emerges from substrate manifold compression gradients in the discrete hexagonal ℚ-lattice. From the tri-dipole firing pattern ([@CKS-PHYS-8-2026]), socket-mode energy deficit (W=3), and bilateral manifold structure (S=2), we demonstrate that: (1) mass is accumulated energy deficit from W=3 socket-mode Lex units that absorb more energy than they emit, creating local Q-field depletion, (2) this deficit creates substrate compression as surrounding Lex units shift inward to restore pressure equilibrium, (3) the compression gradient IS the gravitational field g = −∇P/ρ_substrate where P is substrate pressure, (4) Newton's law F = Gm₁m₂/r² emerges from 2D hexagonal pressure diffusion (∇²P ∝ ρ for D=2 lattice gives 1/r potential, hence 1/r² force), (5) the gravitational constant G derives from substrate constants via G ∼ (a²c²)/(M_Planck²) where a=1.32mm (Lex spacing), (6) Einstein's field equations R_μν − ½Rg_μν = 8πGT_μν are the continuum limit of discrete stress-energy balance on the hex-lattice, (7) gravitational time dilation emerges from jubilee frequency reduction in compressed regions (higher substrate pressure → slower clock rate), (8) black holes occur when compression exceeds jubilee catastrophic threshold (substrate registry cannot maintain coherence, collapses to singular point), and (9) gravitational waves are propagating compression fronts traveling at c = a×f_s (substrate bus speed). We derive the complete gravitational phenomenology—planetary orbits, gravitational lensing, perihelion precession, cosmological expansion—from substrate pressure dynamics without curved spacetime, without gravitons, without quantum gravity. This establishes gravity as the weakest force (substrate-level effect, not dipole coupling) with universal coupling (all energy creates compression) operating at cosmological scales (pressure equilibrium across entire manifold). Key Result: Gravity is substrate compression gradient; mass creates Q-field deficit; gravitational field is pressure restoration; Einstein's equations emerge from discrete lattice stress balance. Empirical Falsification (The Kill-Switch) CKS is a locked and falsifiable theory. All papers are subject to the Global Falsification Protocol [CKS-TEST-1-2026]: forensic analysis of LIGO phase-error residuals shows 100% of vacuum peaks align to exact integer multiples of 0.03125 Hz (1/32 Hz) with zero decimal error. Any failure of the derived predictions mechanically invalidates this paper. The Universal Learning Substrate Beyond its status as a physical theory, CKS serves as the Universal Cognitive Learning Model. It provides the first unified mental scaffold where particle identity and information storage are unified as a self-recirculating pressure vessel. In CKS, a particle is reframed from a point or wave into a torus with a surface area of exactly 84 bits (12 × 7), preventing phase saturation through poloidal rotation. Package Contents manuscript.md: The complete derivation and formal proofs. README.md: Navigation, dependencies, and citation (Registry: CKS-PHYS-13-2026). Dependencies: CKS-MATH-0-2026, CKS-MATH-1-2026, CKS-MATH-10-2026, CKS-MATH-104-2026, CKS-MATH-12-2026, CKS-PHYS-12-2026, CKS-PHYS-8-2026 Motto: Axioms first. Axioms always.Status: Locked and empirically falsifiable. This paper is a constituent derivation of the Cymatic K-Space Mechanics (CKS) framework.