World Year of Physics
Einstein Centennial Colloquium Series
Gravity Probe B: Testing Einstein in Space. A Marriage of Physics and Engineering
C. W. Francis
W. W. Hansen Experimental Physics Laboratory
Einstein’s General Theory of Relativity is the theory we use to interpret the large scale structure of the Universe. Widely, and rightly regarded as among the most beautiful creations of the human mind, it is, nevertheless, problematical for two reasons. It cannot be reconciled with quantum mechanics, the theory we use to interpret the small scale structure of matter, and even today, 90 years after Einstein advanced it, its experimental basis remains surprisingly weak.
Gravity Probe B, launched from Vandenberg Air Force Base on April 20, 2004, will provide two independent, very accurate tests in a cryogenic satellite in a 640 km (400 mile) polar orbit about the Earth. Originally proposed in 1960, GP-B has been a joint development between Stanford University and NASA Marshall Center commenced in 1965, in close collaboration with Lockheed Martin since 1985. GP-B entered its science phase on August 27, 2004 and collected science data until its depletion of helium this September 29. The lecture will describe the total mission and the many novel technologies that have gone into making it a success.
Friday, October 28, 2005