Kinetic Energy and the Equivalence Principle

TL;DR

This paper reexamines experimental data to test whether kinetic energy contributes to gravitational mass as predicted by general relativity, providing new limits on potential violations of the equivalence principle for atomic electrons.

Contribution

It offers the first detailed analysis of experimental data specifically testing the equivalence principle for the kinetic energy of atomic electrons.

Findings

Strong limits on violations of the equivalence principle for atomic electron kinetic energy

Reanalysis supports the prediction that kinetic energy contributes to gravitational mass

Discussion clarifies misconceptions about light's acceleration relative to matter

Abstract

According to the general theory of relativity, kinetic energy contributes to gravitational mass. Surprisingly, the observational evidence for this prediction does not seem to be discussed in the literature. I reanalyze existing experimental data to test the equivalence principle for the kinetic energy of atomic electrons, and show that fairly strong limits on possible violations can be obtained. I discuss the relationship of this result to the occasional claim that ``light falls with twice the acceleration of ordinary matter.''