[FPSPACE] The Gravitomagnetic Influence on Gyroscopes and on the Lunar Orbit

[LARRY KLAES]

General Relativity and Quantum Cosmology, abstract
gr-qc/0702028

From: Thomas Murphy Jr. [view email]

Date: Mon, 5 Feb 2007 18:39:29 GMT   (9kb)

The Gravitomagnetic Influence on Gyroscopes and on the Lunar Orbit

Authors: T. W. Murphy Jr., K. Nordtvedt, S. G. Turyshev

Comments: 4 pages; accepted for publication in Physical Review Letters

Gravitomagnetism--a motional coupling of matter analogous to the Lorentz 
force in electromagnetism--has observable consequences for any scenario 
involving differing mass currents. Examples include gyroscopes located near 
a rotating massive body, and the interaction of two orbiting bodies. In the 
former case, the resulting precession of the gyroscope is often called 
"frame dragging,'' and is the principal measurement sought by the Gravity 
Probe-B experiment.

The latter case is realized in the earth-moon system, and the effect has in 
fact been confirmed via lunar laser ranging (LLR) to approximately 0.1% 
accuracy--better than the anticipated accuracy of the Gravity-Probe-B 
result. This paper shows the connnection between these seemingly disparate 
phenomena by employing the same gravitomagnetic term in the equation of 
motion to obtain both gyroscopic precession and modification of the lunar 
orbit. Since lunar ranging currently provides a part in a thousand fit to 
the gravitomagnetic contributions to the lunar orbit, this feature of 
post-Newtonian gravity is not adjustable to fit any anomalous result beyond 
the 0.1% level from Gravity Probe-B without disturbing the existing fit of 
theory to the 36 years of LLR data.

http://arxiv.org/abs/gr-qc/0702028