A Supplementary Definition of Classification Criteria for Matter and Electromagnetic Waves

Modern physics has long adopted two parallel sets of criteria to distinguish matter and electromagnetic waves: macroscopic classification based on rest mass, and microscopic classification based on particle intrinsic spin. These criteria perform well in most routine scenarios yet possess clear boundary limitations. Neutrinos and ball lightning, two intermediate electromagnetic states, carry both rest mass and intrinsic spin. Classified as matter under existing physical standards, their macroscopic behaviours are consistent with conventional electromagnetic waves. This paper does not overturn established physical theories; it only introduces rigidity and flexibility as supplementary discriminators. The Pauli exclusion principle is utilised to interpret the fundamental difference in spatial occupancy between the two categories. A large quantity of quantifiable, repeatable daily observational evidence is provided for verification: conventional electromagnetic waves and neutrinos propagate at roughly 300,000 kilometres per second and exert no mechanical impact or compressive force on human tissue upon contact. Conventional electromagnetic waves produce thermal or ionising effects, while neutrinos only participate in extremely weak microscopic interactions without observable macroscopic energy release. As low-speed intermediate electromagnetic states, ball lightning merely releases thermal and electric energy when contacting physical matter, with no accompanying mechanical collision response. All arguments are grounded in observable daily phenomena with self-consistent logic, serving as supplementary discriminators within the existing physical framework.This work is the third instalment of a sequential research series. The twopreceding papers are A Spiral Motion Model for Light Propagation Beyond the Straight-Line Approximation and A Fundamental Distinction Between Light Waves and Mechanical Waves Follow-up research will further refine a completeself-consistent electromagnetic-optical theoretical system.