Marked variability in modern-time gravitational data indicates a large secular increase in the mass of ponderable bodies

Abstract

In spite of two hundred years of considerable efforts directed towards improvement in the experimental techniques, gravitational measurements have provided unsettled results for Newton's gravitational constant G. Analysis of the published (over ~75 years) small-scale gravitational measurements, presented in this report, unveils a large secular increase in the gravitational force, that reveals itself as a formal increase in the Newton's constant G at a rate 'G dot per G' = (1.43 +-0.08) x 10^(-5) year^(-1). Since its interpretation as a true 'G dot per G' effect is excluded by laser and radar ranging to the Moon and the interior planets as well as by double-pulsar studies, which all put tight limits on any variation in G, this large secular effect appears to originate in a temporal increase of gravitational masses due to, e.g., capture of mass from a hypothetical cold dark matter halo of the Sun. By virtue of the equivalence principle, the secular mass increase leads naturally to modifications of the Newtonian dynamics in the Solar System, as it predicts a cosmic deceleration of moving bodies dependent upon their speed. In particular, it predicts for the Pioneer 10/11 spacecraft an anomalous, nearly constant acceleration of -(11.0 +-1.8) x 10^(-10) m/s^2, in agreement with the published experimental value of -(8.7 +- 0.9) x 10^(-10) m/s^2. Dynamical effects of this kind have been also detected in the motion of other spacecraft and artificial satellites, but not in the motion of large and/or old objects in the Solar System.