A search for a compositiondependent gravitational force
Abstract
The weak equivalence principle (WEP) maintains that all objects in a uniform gravitational field fall at the same rate, and this rate is independent of composition. I have used the Northfield Mountain Pumped Storage Reservoir as a modulated source of gravitational mass and measured the acceleration of copper and polyethylene test masses towards the reservoir with a sensitive torsion pendulum. The geometry of the pendulum is such that any differential acceleration would manifest itself as a shift in the pendulum period. Therefore, the signature of a WEPviolating force would be a period shift that correlates with the rise and fall of the mass in the Northfield Mountain reservoir. I have looked for such a correlation and find that if there is a difference in the accelerations of copper and polyethylene toward the water in the reservoir, it is less that 6.0 x 10(exp 9) cm/s. We report the limits this places on the possible coupling strength of a possible composition dependent fifth force.
 Publication:

Ph.D. Thesis
 Pub Date:
 1994
 Bibcode:
 1994PhDT.........5N
 Keywords:

 Acceleration (Physics);
 Copper;
 Gravitation;
 Gravitational Fields;
 Polyethylenes;
 Experimentation;
 Pendulums;
 Reservoirs;
 Torsion;
 Thermodynamics and Statistical Physics