THE ELASTIC VACUUM AND THE BILATERAL METRIC (IV v6)

Standard General Relativity treats the spacetime metric as an autonomous dynamical continuum without specifying its underlying microscopic medium. In the pregeometric framework of FCD-RBv6, we formalize the physics of the vacuum as a 5D elastic substrate in an AdS5 warped background. Space emerges as the macroscopic envelope of a bilateral network of trans-brane Einstein-Rosen (ER) bridges under finite elastic tension (σ0 ≈ 0.99 GeV/fm). We derive the speed of light as the characteristic shear wave velocity of the pregeometric bulk, c = √(μ_bulk / ρ_bulk), linking relativistic invariance directly to the mechanical properties of the 5D manifold. We analyze the bilateral deformation field L(x,t) between Brane A and Brane B, showing that gravitational attraction emerges not from a mechanical fluid medium, but from the statistical depletion of bulk vacuum microstates around zero-entropy baryonic defects