What Do Experiments in Optics tell us about Photon Momentum in Media?

TL;DR

This paper analyzes eight optical experiments to clarify the photon momentum in media, concluding that Minkowski's formulation is generally more natural and convenient than Abraham's in physical and canonical contexts.

Contribution

It provides a systematic analysis of experiments related to photon momentum, clarifying the practical relevance of Minkowski versus Abraham formulations in electrodynamics.

Findings

Minkowski energy-momentum tensor is divergence-free and forms a four-vector.

Experiments show Minkowski's formulation is more natural in physical situations.

Some experiments are incapable of informing about photon momentum in media.

Abstract

In order to get some insight in the intricacies of the Abraham-Minkowski energy-momentum problem in phenomenological electrodynamics, we briefly analyze eight different experimental situations in radiation optics. Six of the experiments are already existing, while the remaining two are suggestions for future endeavors. Among the first six, we distinguish between three which are incapable of informing about photon momentum in a medium, and the remaining three which are able to give us useful information. Our general conclusion is that the Abraham-Minkowski "problem" is essentially a matter of convenience. In actual physical situations it is the Minkowski expression which is most natural alternative to employ. Also, in a canonical context, it is the Minkowski energy-momentum tensor which is the most convenient alternative to work with, as this tensor is divergence-free causing the total radiation momentum and energy to make up a four-vector, although notably a spacelike one.