This paper derives the sonoluminescence flash energy from the Landauer principle — without free parameters — and identifies a universal structural rule governing phase transitions across nine physical domains. Core result: The ratio η = ∂/I (boundary information divided by total information, in bits) predicts the photon count of cavitation luminescence (predicted: 1.2 × 10⁶, measured: ~10⁶) and reproduces exact results from the Onsager 2D Ising solution (η = 0.5673), BCS superconductivity at weak coupling (η = 0.5667), the mean-field Curie point (η = 2/3), the percolation threshold, Bose-Einstein condensation (η = 1/ζ(3/2)), Lindemann melting, and the Bekenstein-Hawking entropy bound (η = 1/8π at Planck mass). Key claims: The sonoluminescence flash is not thermal radiation. It is the momentary visibility of carrier-free information at the geometric null point of a spherically collapsing cavity. The escape fraction η ≈ 4 × 10⁻⁷ in water is scale-invariant across three orders of magnitude in bubble radius. The Ising-BCS identity (η = 0.567 in both) demonstrates universality class membership as a single number. The cavitation bubble is a thermodynamic black hole: collapse → horizon at critical radius → radiation (Hawking analogue). η = ∂/I provides the theoretical foundation for the previously phenomenological Δ-Gate formalism (DOI: 10.5281/zenodo.19103765). Five testable predictions are stated, including non-thermal spectral signatures, convergence of emission radius toward zero, and linear temperature scaling in low-vapor-pressure media. Part of the Δ-Gate Formalism research program.
Fabio Luigi Zander (2026) studied this question.