Abstract: Gravity Probe B (GP-B), launched 20 April 20 2004, is a space-based physics experiment to test two predictions of Einstein's theory of general relativity, the geodetic and frame-dragging effects. Four precision, cryogenically cooled gyroscopes in earth orbit allow redundant measurement of the two effects. Data analysis, since 29 September 2005 when science data collection concluded, has resulted in the identification and separation of three Newtonian effects from the science data. Both relativity effects are now plainly visible in the analyzed data with a current statistical uncertainty in the East-West direction (frame-dragging) of 5.4 marc-s/yr (~14% of the predicted effect). It is emphasized that this is a preliminary result requiring the completion of a detailed systematic error analysis.
Bio: Barry Muhlfelder graduated with a Ph.D in physics from the University of Rochester. As a National Research Council Fellow at NIST, he continued his doctoral work on thin-film SQUID sensors. After joining the GP-B group he co-led the development of the gyroscope London Moment Readout Group. Following the completion of the GP-B science data collection, he contributed to the understanding of systematic uncertainty in the GP-B science result. Currently, he serves as the GP-B Program Manager.
Time: 4:00pm – 5:30pm
Location: Physics and Astrophysics Conference Room 102/103
Light refreshments available 4:15pm; Presentation begiins 4:15pm.
Open to All