The laws of nature can only be revealed through experimentation. A glaring deficiency in our understanding of those laws is the role played by time reversal symmetry violation, the connection between time and the physical forces. Because an electric dipole moment (EDM) can exist only if time-reversal symmetry is violated, the mercury EDM project will search for time reversal symmetry violation within the mercury atom. The size of the EDM will shed light on the correct description of the laws of nature. The signature of an EDM is a shift of the nuclear spin precession frequency (the signal used in MRI machines) when an electric field is applied to the atoms. The experiment will measure the effect of an electric field on the precession frequency to unprecedented accuracy and perhaps be the first experiment to detect a non-vanishing EDM.
The notion of time reversal symmetry and its violation appeals to the general public as well as a broad physics community. Within physics, EDM experiments are of interest to the atomic, nuclear, high energy, and astrophysics communities, both experimentalists and theorists alike. The mercury EDM project is a "table-top" experiment, giving graduate, undergraduate, and high school students the opportunity to work locally on a small-scale experiment in which they can explore fundamental issues normally studied only by large groups at high energy accelerators. These students gain experience in exquisite technology with atoms, lasers and electronics, and in turn help make advances in this technology that they take with them to their future careers. The techniques developed to measure nuclear spin precession frequencies to unprecedented accuracy are transferred to researchers in other fields where precision magnetometry is paramount.