Breakdown of the isotropy of diffuse radiation as a consequence of its diffraction at multidimensional regular structures

TL;DR

This paper experimentally demonstrates that diffuse radiation loses isotropy when diffracted by multidimensional structures, challenging assumptions of statistical physics about microstates and macrostate probabilities.

Contribution

It provides experimental evidence of anisotropy in diffuse light caused by diffraction, suggesting a need to revise statistical physics principles for nonergodic systems.

Findings

Significant deviation from Lambert's law observed.

Angular anisotropy of radiation fluxes detected.

Diffuse photon gas becomes anisotropic after diffraction.

Abstract

This article is devoted to the results of an experimental test of the theoretical assumption that the basic axiomatic postulate of statistical physics according to which it is equally probable for a closed system to reside in any of the microstates accessible to it may be invalid for nonergodic cases. In the course of photometric experiments for the purpose of recording the predicted loss of isotropy by a diffuse light field when it came into contact with a two-dimensional phase-type diffraction grating, a significant deviation from Lambert's law was detected when the diffuse photon gas was scattered by the grating surface. This caused angular anisotropy of the radiation fluxes to appear in the initially homogeneous light field. These results provide a basis for revising the determination of the most probable macrostate of a closed system.