Chien Hung Hsiang Elastic Membrane Cosmology 9.5AbstractWe propose a fundamental paradigm shift in cosmology, transitioning from particle-based reductionism to a unified environmental-dynamic framework: Chien’s Hydrodynamic Cos-mology (CHC). Instead of abstract fields, we model the universe as a physical membrane—a Bubble—nucleating and rising within a 5D Superfluid Bulk (Quantum Vacuum). Core mechanisms in Version 9.5 include:1. Origin as Cavitation: The Big Bang is identified as a Quantum Cavitation event.Inflation is driven by a Bulk Shockwave ("The Kick") and exits naturally as thewave passes. 2. Hydrodynamic Dark Sector: "Dark Energy" is reinterpreted as Buoyancy (the bubble’s ascent toward lower pressure), and "Dark Matter" as Viscous Drag (themembrane’s resistance to motion). 3. The Titan Effect: We explain the "impossible" maturity of early galaxies (JWST) via Environmentally Assisted Implosion. In the deep-sea high-pressure epoch(z > 100), stars collapsed directly into black holes. 4. The Chien Power Limit: We define a membrane yield strength PChien ≈ 10^56 erg/s. Extreme events like GW231123 breach this limit, causing energy leakage (Cavitation)into the Bulk.5. The Great Flip: The cosmic cycle ends not in heat death, but in a Chien Eversion—a topological turning-inside-out upon reaching the Bulk surface, followed by implosionand reset.We validate this framework against 2026 data, explaining the **Cosmic Dipole** as bulk currents, the **Big Ring** as impact ripples, and **RBH-1** as a gravitationally towed anomaly. CHC offers a sustainable, particle-free ontology for the universe.Keywords: Quantum Cavitation, Buoyancy, Viscous Drag, Titan Effect, Chien Power Limit,Cosmic Dipole, Chien Eversion.