Freiburg 2008 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 12: Experimente zur Gravitation II

GR 12.2: Talk

Thursday, March 6, 2008, 14:20–14:40, KGI-HS 1010

Laboratory test of gravitational drag? — •Johan K. Fremerey — Karl-Friedrich-Schinkel-Str. 14, D-53127 Bonn, Germany

In the early 1960s, J. C. Keith on the basis of both, Birkhoff's and Einstein's theories of gravitation proposed the existence of a rotational drag [1,2] besides the one caused by the generally accepted gravitational quadrupole radiation. A rotational drag as expected by Keith was experimentally observed in the early 1970s on a magnetically suspended, 2.5-mm steel ball spinning freely at rotational frequencies up to and beyond the elastic limit of the rotor material [3]. The laboratory observations have been disapproved by gravitational physicists as being incompatible with the observation of extraterrestrial objects [4,5]. The apparent discrepancy, however, can be resolved by simply assuming that the gravitational interaction postulated by Keith does not penetrate compact matter such as, in particular, the atomic nuclei contained in the experimental rotor. On grounds of this consideration, the Keith effect is expected to be observable only on small rotating bodies as these are widely transparent to the interaction.

[1] J.C. Keith, J. Math. Phys. 42, 248 (1963). [2] J.C. Keith, Rev. Mex. Fis. 12, 1 (1963). [3] J.K. Fremerey, Phys. Rev. Lett. 30, 753 (1973). [4] M. Reinhardt, A. Rosenblum, Lett. Nuovo Cimento 6, 189 (1973). [5] G.T. Gillies, Rev. Roum. Phys. 30, 805 (1985).