This work introduces the Compression–Oscillation Duality, a developing theoretical framework in which inward geometric compression and outward vibrational oscillation are treated as conjugate phases of a single underlying process. The proposal aims to offer a unifying perspective for understanding gravitational curvature and quantum-like oscillatory behavior through a shared continuum-based structure. In this model, compression CCC represents the inward, geometric configuration of the medium—analogous to curvature, gravitational wells, and structural confinement. Oscillation OOO emerges as the continuum-derivative of compression, forming a π/2\pi/2π/2 phase-shifted counterpart responsible for wave-like and resonance behavior. Together, the fields evolve along a continuum parameter C\mathcal{C}C, which serves as the generator of change and the link between geometric and vibrational phases. The work builds on: a dual-field formalism connecting compression and oscillation, a Lagrangian and action principle, a tensor-based interpretation compatible with aspects of General Relativity, an emerging analogy to quantum phase evolution, a hierarchical view of planets, stars, galaxies, and cosmic structures as layered compression wells, early predictions involving resonance patterns, quantization, and free-fall interpretation. This project is the result of extensive conceptual exploration, repeated questioning, iterative testing, and continuous relearning. It is not a finished or complete theory; rather, it represents a step toward a more coherent understanding of how inward geometry and outward vibration might coexist within a single framework. Many components—especially the fully relativistic formulation, empirical constraints, and deeper quantum interpretation—remain open for further development. The document is shared here in the spirit of transparency, collaboration, and ongoing refinement, with the intention of improving and expanding the model through future work and scientific feedback.