Cosmological Tank Postulate in Lava-Void Cosmology

The Cosmological Tank Postulate: A Self-Contained General-Relativistic Closure Within Lava-Void Cosmology

By C. Rich 

The Cosmological Tank Postulate asserts that the ensemble of mathematical structures emerging from quantum-gravity research—amplituhedra, twistor grassmannians, causal sets, spin networks, holographic tensor networks, and algebraic bootstrap objects—constitutes the global boundary interface of a single, asymptotically bounded spacetime volume. This boundary is the ultimate, self-dual lava-void wall operating simultaneously at the Planck and cosmological horizons, enforcing unitary evolution and thermodynamic consistency without leakage into a multiverse.

Core Axioms

1. Fluid Continuity: The observable spacetime–matter continuum is a compressible, inhomogeneous fluid governed by standard Einstein equations with zero cosmological constant. Quantum foam is the Planck-regime manifestation of the same fluid, exhibiting violent curvature fluctuations analogous to capillary waves at lava-void interfaces.
2. Hierarchical Void Nesting: Voids are self-similar across scales. Local underdensities (KBC void) are nested within larger voids, culminating in a terminal void whose interior comprises the entire causally connected region. The boundary of this terminal void is the “tank wall.”
3. Interfacial Self-Duality: The tank wall is a maximal-curvature, negative-surface-tension interface where Planck-scale and cosmological-scale voids become indistinguishable. It is simultaneously the quantum-gravity regulating structure and the infrared cosmological horizon, satisfying self-dual boundary conditions ($(\ell_{Planck} \times R_{horizon} \approx \ell_{Planck}^2 / G)$ with appropriate factors).
4. Algebraic Emergence: The mathematical objects discovered via bootstrap programmes are holographic encodings of scattering amplitudes and entropy on this terminal interface. They are not platonic possibilities external to our universe but the unique consistency conditions that permit a void-dominated fluid to remain bounded and stable.
5. No Exterior Required: All apparent multiversal branching is internal selection among transient foam configurations inside the tank. The Law of Variable Complexity operates solely within this volume, with observer-participants retrocausally stabilising the boundary conditions that appear “fine-tuned.”

Immediate Consequences

• The Hubble Tension and late-time acceleration arise from our off-centre position relative to the tank’s interfacial repulsion, exactly as in standard LVC.
• Black-hole singularities are replaced by Planckian void cores; the information paradox dissolves because the horizon is a mini-tank wall with identical algebraic encoding.
• Quantum gravity is fully background-independent yet globally bounded—no external multiverse or landscape is necessary or permissible.

This postulate completes Lava-Void Cosmology by providing the missing global topology: a single, finite-but-unbounded (in the Einstein-static sense) fluid volume whose self-consistent boundary is the very algebraic structure theorists have been mapping from within. The fish tank is not outside GR—it is the most elegant solution GR permits when voids dominate and interfaces close the system upon itself.

We now possess a fully closed, multiverse-free, general-relativistic unification from Planck foam to cosmological voids. The paradigm is sealed.

C. Rich