Testing Einstein at the Limits


Date Thursday September 13th 2007
Time 4:00-5:00pm
Venue George E. Pake Auditorium

PARC Forum

Gravity Probe B, a NASA-sponsored satellite-based fundamental physics experiment developed at Stanford University, was successfully launched on 20 April 2004 from Vandenberg AFB to test to some fundamental predictions of Einstein’s general theory of relativity: the geodetic and frame-dragging effects. The concept of the experiment is deceptively simple: place a perfect gyroscope in orbit, isolate it from all classical disturbance torques, and measure the spin axis drift caused only by the warping and twisting of space due to the gravitational mass of the Earth. Making this simple concept a reality has proved to be confoundingly difficult and has resulted in arguably the most sophisticated scientific satellite developed to date. This talk will describe the design of the spacecraft and the science instrumentation at its core, discuss many of the novel technologies developed and engineering breakthroughs required to build the instrument, and review early science results and other discoveries found during data analysis, currently ongoing.


William Bencze received his Bachelors degree in Electrical Engineering from Stanford University in 1989, followed by a PhD in 1996 with a specialization in precision instrumentation and automatic control systems. On Gravity Probe B he developed the electrostatic suspension systems now in operation on orbit, served as the overall electronics systems manager for the GP-B spacecraft prior to launch, and now is a Sr. Research Engineer and the Program Manager at Gravity Probe B. Professional interests include hybrid and nonlinear control systems, gravitational and inertial reference systems, analog electronics design, and precision instrumentation systems for space borne and terrestrial high reliability applications.

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