Searching for New Forces Using Torsion Pendula

Equivalence principle violation, deviations from the inverse-square law of gravity, and long-range interactions between particle spins o�er powerful tests of beyond-the-standard-model physics. Using a torsion pendulum, a technique that dates to the 18th century, is still the most sensitive way to search for these signatures of new physics. I will talk about how the experiments are done and give an update on the current and future status of such torsion balance experiments in the Eot-Wash group.