This award supports an experimental research program to test Newton's inverse-square law of gravitation to better than one part in 100 at a 100-micrometer range and to search for hypothetical extra space dimensions down to 10 micrometers. The source mass for the gravitational force measurement is designed to generate no Newtonian signal. To reduce thermal noise that could mask a signal, the experiment is cooled to liquid helium temperatures. Any inverse-square law violation signal is detected by a highly sensitive superconducting differential accelerometer formed by two superconducting test masses.
This research will explore the very nature of spacetime and test the foundations of General Relativity and theories beyond the Standard Model of particle physics. The confirmed observation of a deviation from Newton's law at short distance would revolutionize our understanding of gravity and could lead to a unification of all fundamental forces. The cryogenic technique that this laboratory has developed for measuring extremely weak forces is of potential value in a variety of other fields which require measurement of minute forces.