An Exploratory Theoretical Framework for a Spacetime-Fluid Interpretation and Its Optical-Metric Analogues

This paper explores an alternative theoretical framework in which the fabric of spacetime is conceptualized not merely as a passive geometric manifold, but as an effective physical fluid medium. By examining the weak-field limit of general relativity and mapping null geodesics to an optical equivalent refractive-index model, we derive the bending of light around massive bodies and compare it with Sir Arthur Stanley Eddington’s historic 1919 solar eclipse observations. Furthermore, we investigate the thermodynamic and mechani- cal analogues of this fluid hypothesis—including effective vacuum energy density, negative pressure, compressibility, and viscosity—while critically addressing the physical limitations, coordinate dependencies, and the cosmological constant problem.