The Lorentz Force and the Radiation Pressure of Light

TL;DR

This paper critiques traditional explanations of light's pressure on matter, highlighting mathematical and conceptual issues, and offers an alternative demonstration to better illustrate the Lorentz force and radiation pressure.

Contribution

It identifies flaws in classical derivations of light pressure and proposes a new, clearer demonstration to improve understanding at the introductory physics level.

Findings

Traditional derivations are mathematically incorrect

Classical explanations face conceptual difficulties

An alternative demonstration clarifies the Lorentz force and radiation pressure

Abstract

In order to make plausible the idea that light exerts a pressure on matter, some introductory physics texts consider the force exerted by an electromagnetic wave on an electron. The argument as presented is both mathematically incorrect and has several serious conceptual difficulties without obvious resolution at the classical, yet alone introductory, level. We discuss these difficulties and propose an alternate demonstration.