Place: 2241 Chamberlin Hall (coffee and cookies at 3:30 pm)
Speaker: Jens Gundlach, University of Washington
Abstract: In the last two decades torsion balances have been reintroduced to modern physics. We have built highly refined torsion balances to search for subtle deviations from ordinary weak-field gravity; in particular, we have tested the equivalence principle to unprecedented precision, including a test searching for non-gravitational accelerations towards dark matter. We have built special torsion balances to test the 1/r2-law of gravity for distance scales as small a few tens of micrometers. Furthermore we have measured Newton's constant with unmatched precision and have tested F=ma. We are also using our ultra-sensitive torsion balance instruments to look for stray forces that may affect the gravity wave observatories LIGO and LISA.