This version consolidates and extends the experimental foundation of USP Field Theory. The original gravity challenge paper has been paired with a broader experimental roadmap, introducing three precise and testable predictions: 1. Spin-Tension Gravity Gradient: A proposed experiment using ultra-sensitive gravimeters to detect gravitational differences between materials of equal mass but differing atomic-core densities — testing if gravity arises from spin tension rather than spacetime curvature. 2. Magnetic Flip Trigger Equation: A new model connects Earth's magnetic field instability to a misalignment in rotational harmony between core layers, introducing measurable Δω as a precursor signal. 3. Photon Delay Reinterpretation: Using femtosecond laser interferometry, this test measures photon delay across optically identical but structurally different glass — revealing whether geometry, not intrinsic speed, causes delay. Together, these experiments shift gravitational and electromagnetic behavior from abstract geometry to field-based dynamics, making USP Field Theory increasingly verifiable with current instruments.