19
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Lunar Laser Ranging Tests of the Equivalence Principle with the Earth and Moon

      Preprint
      , ,

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          A primary objective of the Lunar Laser Ranging (LLR) experiment is to provide precise observations of the lunar orbit that contribute to a wide range of science investigations. Time series of the highly accurate measurements of the distance between the Earth and Moon provide unique information used to determine whether, in accordance with the Equivalence Principle (EP), both of these celestial bodies are falling towards the Sun at the same rate, despite their different masses, compositions, and gravitational self-energies. Current LLR solutions give \((-1.0 \pm 1.4) \times 10^{-13}\) for any possible inequality in the ratios of the gravitational and inertial masses for the Earth and Moon, \(\Delta(M_G/M_I)\). This result, in combination with laboratory experiments on the weak equivalence principle, yields a strong equivalence principle (SEP) test of \(\Delta(M_G/M_I)_{\tt SEP} = (-2.0 \pm 2.0) \times 10^{-13}\). Such an accurate result allows other tests of gravitational theories. The result of the SEP test translates into a value for the corresponding SEP violation parameter \(\eta\) of \((4.4 \pm 4.5)\times10^{-4}\), where \(\eta = 4\beta -\gamma -3\) and both \(\gamma\) and \(\beta\) are parametrized post-Newtonian (PPN) parameters. The PPN parameter \(\beta\) is determined to be \(\beta - 1 = (1.2 \pm 1.1) \times 10^{-4}\). Focusing on the tests of the EP, we discuss the existing data, and characterize the modeling and data analysis techniques. The robustness of the LLR solutions is demonstrated with several different approaches that are presented in the text. We emphasize that near-term improvements in the LLR ranging accuracy will further advance the research of relativistic gravity in the solar system, and, most notably, will continue to provide highly accurate tests of the Equivalence Principle.

          Related collections

          Most cited references41

          • Record: found
          • Abstract: not found
          • Article: not found

          Tensor-scalar cosmological models and their relaxation toward general relativity

            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            General relativity as a cosmological attractor of tensor-scalar theories.

            (1993)
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Lunar laser ranging: a continuing legacy of the apollo program.

              On 21 July 1969, during the first manned lunar mission, Apollo 11, the first retroreflector array was placed on the moon, enabling highly accurate measurements of the Earthmoon separation by means of laser ranging. Lunar laser ranging (LLR) turns the Earthmoon system into a laboratory for a broad range of investigations, including astronomy, lunar science, gravitational physics, geodesy, and geodynamics. Contributions from LLR include the three-orders-of-magnitude improvement in accuracy in the lunar ephemeris, a several-orders-of-magnitude improvement in the measurement of the variations in the moon's rotation, and the verification of the principle of equivalence for massive bodies with unprecedented accuracy. Lunar laser ranging analysis has provided measurements of the Earth's precession, the moon's tidal acceleration, and lunar rotational dissipation. These scientific results, current technological developments, and prospects for the future are discussed here.
                Bookmark

                Author and article information

                Journal
                19 July 2005
                2009-01-02
                Article
                10.1142/S021827180901500X
                gr-qc/0507083
                52c2c745-0854-49ba-9092-4f04f559f8c4

                http://arxiv.org/licenses/nonexclusive-distrib/1.0/

                History
                Custom metadata
                Int.J.Mod.Phys.D18:1129-1175,2009
                50 pages, 18 figures, 4 tables
                gr-qc

                Comments

                Comment on this article