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Updated: Apr 24, 2026
12:14
The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
22.6K
A simple pendulum laser interferometer for determining the gravitational constant.
Harold V Parks1, James E Faller2
1JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309, USA Sandia National Laboratories, Albuquerque, NM 87185, USA harold.parks@nrc-cnrc.gc.ca.
Summary
Scientists measured the Newtonian constant of gravitation (G) using a suspended laser interferometer. This experiment utilized two pendulums and a laser to detect minute changes in gravitational force.
Area of Science:
- Experimental Physics
- Gravitational Physics
- Metrology
Background:
- The Newtonian constant of gravitation (G) is a fundamental constant in physics.
- Precise measurement of G is crucial for testing gravitational theories and understanding the universe.
- Previous experiments have faced challenges in achieving high precision.
Purpose of the Study:
- To measure the Newtonian constant of gravitation (G) with a novel suspended laser interferometer apparatus.
- To refine experimental techniques for gravitational constant determination.
Main Methods:
- Employed a suspended laser interferometer with two simple pendulums (72 cm length, 34 cm separation).
- Utilized a Fabry-Perot cavity formed by mirrors on pendulum bobs.
- Measured pendulum separation changes using a locked laser as a gravitational field was modulated by displacing tungsten masses (120 kg each).
Main Results:
- Detailed account of the 2004 experimental setup and procedure.
- Data analysis focused on detecting gravitational field-induced changes in pendulum separation.
Conclusions:
- The experiment provided a method for measuring the gravitational constant using laser interferometry.
- The findings contribute to the ongoing effort to precisely determine the Newtonian constant of gravitation.
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