Comment on "Measurements of Newton's gravitational constant and the length of day"

TL;DR

This paper critically evaluates claims of a 5.9-year periodicity in Newton's gravitational constant measurements, finding that models with additional Gaussian noise better explain the data than sinusoidal models suggesting periodicity.

Contribution

It applies Bayesian model comparison to test the periodicity claim, demonstrating that a noise-based model is strongly favored over sinusoidal models.

Findings

Gaussian noise model is strongly favored over sinusoidal models

No significant evidence for periodicity in G measurements

Updated data set supports noise-dominant explanation

Abstract

There have been recent claims (Anderson et al., EPL, 110, 10002) of a 5.9 year periodicity in measurements of Newton's gravitational constant, $G$, which show a very strong correlation with observed periodic variations in the length of the day. I have used Bayesian model comparison to test this claim compared to other hypotheses that could explain the variation in the $G$ measurements. I have used the data from the initial claim, and from an updated set of compiled $G$ measurements that more accurately reflect the experimental dates, and find that a model containing an additional unknown Gaussian noise component is hugely favoured, by factors of $\gtrsim e^{30}$, over two models allowing for a sinusoidal component.