Flash During Bubble Collapse: Inward Geometry and Irreversible Energy Emission

This paper addresses the long-standing question of why light appears during the collapse of a gas bubble in sonoluminescence. Rather than proposing a new microscopic emission mechanism, it reframes the problem at a foundational level, arguing that light emission is an unavoidable outcome of rapid inward geometric contraction and irreversible energy reconfiguration. Using principles of energy compatibility, configuration sustainability, and geometric constraint, the work shows why multiple competing mechanistic models coexist without contradiction. Sonoluminescence is presented as a case study of a general physical rule governing irreversible energy emission in strongly confined, non-equilibrium systems. The paper emphasizes conceptual clarity and proposes validation through reanalysis of existing experimental data rather than new experiments.