TEST OF GENERAL RELATIVITY : 1995 - 2002 MEASUREMENT OF FRAME - DRAGGING Ignazio Ciufolini

After an introduction on phenomena due to spin and mass-energy currents on clocks and photons, we review the 1995-2001 measurements of gravitomagnetic field of Earth and Lense-Thirring effect obtained by analyzing the orbits of the two laserranged satellites LAGEOS and LAGEOS II; this method has provided a direct measurement of Earth’s gravitomagnetism with accuracy of the order of 20 %. A future accurate measurement of the Lense-Thirring effect, at the level of 1% accuracy, may include the LARES experiment that will also provide other basic tests of general relativity and gravitation. Finally, we report the latest measurement of the LenseThirring effect, obtained in 2002 with the LAGEOS satellites over nearly 8 years of data. This 2002 result fully confirms and improves our previous measurements of the Earth frame-dragging: the Lense-Thirring effect exists and its experimental value is within ∼ 20% of what is predicted by Einstein’s theory of general relativity.