Temporal Variation of Earth-Based Gravitational Constant Measurements

Abstract

As one knows, strong discrepancies are found between the different precise measurements of the gravitational constant carried out in Earth-based laboratories. While the precision is increasing in different laboratories and with various methods, these measurements are even more and more discordant. We have shown since 2002 that an improved 5D Kaluza-Klein (KK) theory may provide a satisfactory explanation to these discrepancies by referring to the geomagnetic field as a possible cause. Here we take advantage of different precise measurements performed on the same location but at different epoch to address the temporal variation of the gravitational constant measurements. It turns out that taking into account the secular variation of the geomagnetic potential introduces a greater consistency into the apparent lack of concordance amongst the most precise gravitational constant measurements. Indeed, we obtain results that are in good agreement with all laboratory measurements. Moreover, this study yields an independent way to derive the coupling constant of the internal 5D KK scalar field to the electromagnetic field, namely, F⁻¹ = (3.25 ± 0.35) × 10⁻¹⁴ m/J, which matches quite well with the earlier one, F^-1 = (3.40 ± 0.41) × 10⁻¹⁴ m/J.