Null Result for the Violation of Equivalence Principle with Free-Fall Rotating Gyroscopes

TL;DR

This study used a double free-fall interferometer to test the equivalence principle with rotating gyroscopes and found no differential acceleration, supporting the principle's validity for rotating extended bodies at the tested sensitivity.

Contribution

The paper provides the first direct measurement of differential acceleration between rotating and non-rotating bodies in free fall, confirming the equivalence principle at a new sensitivity level.

Findings

No differential acceleration observed at 2x10^{-6} level.

No evidence of anti-gravity effects in rotating gyroscopes.

Supports the universality of free fall for rotating extended bodies.

Abstract

The differential acceleration between a rotating mechanical gyroscope and a non-rotating one is directly measured by using a double free-fall interferometer, and no apparent differential acceleration has been observed at the relative level of 2x10{-6}. It means that the equivalence principle is still valid for rotating extended bodies, i.e., the spin-gravity interaction between the extended bodies has not been observed at this level. Also, to the limit of our experimental sensitivity, there is no observed asymmetrical effect or anti-gravity of the rotating gyroscopes as reported by hayasaka et al.