A spectral law for blackbody radiation without temperature or Planck’s constant

Methodological Note:The approach taken here is empirical.We begin with measured spectral quantities and examine the mathematical relations among them without imposing theoretical interpretations as primary organizing principles.The question is whether these relations are sufficient to organize, explain and predict the observations.The absence of conventional theoretical entities or mechanisms is therefore not an omission, but part of what the analysis tests.The resulting relations are evaluated through agreement with measurements, quantitative predictive accuracy, parsimony, generality across physical systems, and explanatory power through measured structural constraints.The present work is self-contained and independently testable, but forms part of a broader empirical research program, the Spectral Framework, investigating the low-dimensional empirical spectral organization underlying atomic and physical systems.