Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"

TL;DR

This paper critically examines Rothleitner et al.'s measurement of the speed-of-light perturbation in absolute gravimeters, highlighting that their conclusion underestimates the effect due to overlooked parasitic perturbations, thus questioning the validity of their findings.

Contribution

It provides a critical commentary identifying errors and unaccounted factors in the original measurement of the speed-of-light perturbation.

Findings

Original measurement underestimated the perturbation effect.

Unaccounted parasitic perturbations influenced the results.

The reported perturbation value violates fundamental physics principles.

Abstract

The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.