Test of the gravitational inverse-square law at 0.4- to 1.4-m mass separations

Using a superconducting gravimeter, we have measured the force on a spherical shell of Nb due to the presence of a spherical mass $M$ that is periodically moved up and down on an elevator underneath the gravimeter. Over a distance range from 0.4 to 1.4 m Newton's inverse square law is verified to a precision of ±1%. At a 95% confidence level, our data restrict the coupling constant $\alpha$ of a non-Newtonian Yukawa potential to be $\left|\alpha \right|<\mathrm{}0.012G$ for Yukawa ranges from 0.2 to 2.0 m.