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Detection of earth rotation with a diamagnetically levitating gyroscope

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Abstract

Strong magnetic fields allow levitation of apparently nonmagnetic substances due to their weak but not negligible diamagnetic response of about 10−5. Importantly, the diamagnetic force compensates gravity on the level of individual atoms and molecules and, therefore, can be used to mimic a continuous zero-gravity environment that, otherwise, is only achievable on board of a space station. Here we employ this earth-bound low gravity to demonstrate a simple mechanical gyroscope with sensitivity already comparable to that achieved by quantum and military gyroscopes. Our gyroscope can serve as a “shooting range” for the development of precision orbiting gyroscopes that have been a subject of intensive discussions regarding possible tests of general relativity.

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A high-accuracy orbiting relativity experiment is described. A pure unsupported gyroscope in a spinning drag-free satellite at ambient temperatures with conventional optical instrumentation can measure relativity drifts with errors as low as 3-0.1 arc musec/yr, an improvement of 102-103 over the current GP-B experiment. Recent theoretical work has suggested that the post-Newtonian parameter 1-gamma~1/omegaBD might lie in the range 10-4- 10-8, signaling the presence of a massless scalar field. The experiment described here could measure gamma to an accuracy between 10-7 and 10-8; for the highest accuracies, the measurement depends critically on future microarcsecond astrometry or a two-gyro version of the experiment.
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