What is it about?

Models for the spectral intensities emitted from heated matter both solids and liquids and for the total internal density of photons. The models have been validated by spectral observations of emission as a function of temperature in the laboratory and in remote sensing geophysical studies of earth's oceans and landscapes. The models also enable quatitative analysis of the internal composition of matter.

Featured Image

Why is it important?

These observed external intensities are different in direction and spectral content to those predicted by the Kirchhoff Rule as the intensities are generated internally and are refracted if they exit. That means for absorbing matter reversal of exit rays do not reproduce in original internal incident rays. Errors are largest for intensities that exit into more oblique directions while many internal intensities cannot escape at all as they are totally internally reflected. Radiative cooling rates obey new expressions unique to each material but past studies often seemed to work as all fluxes vary as T^4.

Perspectives

Planck admitted in his Nobel speech 1920 he had to rely on the Kirchhoff rule and assumptions about the source of exit photons in "his" ground breaking model that stayed in use for over a century. He kept looking for a first principle model until his passing without success but hinted in his autobiography (published in 1949) that the new science of many-body quantum physics that emerged in the 1930s and 40's might provide the answer he sought. That and the large amount of published evidence that the old model did fail in many precise optical and thermal experiments led to these quantum models

Professor Geoff Smith
University of Technology Sydney

Read the Original

This page is a summary of: Partial coherence and amplified internal energy when thermal radiation is sourced within matter, Journal of Physics Communications, June 2022, Institute of Physics Publishing,
DOI: 10.1088/2399-6528/ac78c1.
You can read the full text:

Read

Contributors

The following have contributed to this page