Effect of Earth's rotation on the trajectories of free-fall bodies in Equivalence Principle Experiment

TL;DR

This paper investigates how Earth's rotation influences free-fall trajectories, proposing a method to detect tiny deviations caused by potential violations of the equivalence principle using sensitive magnetometers.

Contribution

It introduces a novel approach to test the equivalence principle by analyzing free-fall experiments involving rotating and non-rotating bodies with high precision.

Findings

Difference in orbits is about 10^{-9} cm for 40 seconds of free fall.

SQUID magnetometers can detect displacements as small as 10^{-13} cm.

Potential to observe violations of the equivalence principle through orbital deviations.

Abstract

Owing to Earth's rotation a free-fall body would move in an elliptical orbit rather than along a straight line forward to the center of the Earth. In this paper on the basis of the theory for spin-spin coupling between macroscopic rotating bodies we study violation of the equivalence principle from long-distance free-fall experiments by means of a rotating ball and a non-rotating sell. For the free-fall time of 40 seconds, the difference between the orbits of the two free-fall bodies is of the order of 10^{-9}cm which could be detected by a SQUID magnetometer owing to such a magnetometer can be used to measure displacements as small as 10^{-13} centimeters.