New Test of the Equivalence Principle from Lunar Laser Ranging
Abstract
An analysis of six years of lunar-laser-ranging data gives a zero amplitude for the Nordtvedt term in the Earth-Moon distance yielding the Nordtvedt parameter η=0.00+/-0.03 Thus, Earth's gravitational self-energy contributes equally, +/-3%, to its inertial mass and passive gravitational mass. At the 70% confidence level this result is only consistent with the Brans-Dicke theory for ω>29. We obtain |β-1|<~0.02 to 0.05 for five-parameter parametrized post-Newtonian theories of gravitation with energy-momentum conservation, or |β-1|<~0.01 if only β and γ are considered.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 1976
- DOI:
- 10.1103/PhysRevLett.36.551
- Bibcode:
- 1976PhRvL..36..551W
- Keywords:
-
- Earth-Moon System;
- Equivalence;
- Gravitational Fields;
- Laser Range Finders;
- Lunar Rangefinding;
- Relativistic Effects;
- Data Reduction;
- Energy Conservation;
- Gravitation Theory;
- Lunar Orbits;
- Momentum Theory;
- Relativity;
- Astrophysics