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Simple pendulum determination of the gravitational constant.
Harold V Parks1, James E Faller
1JILA, University of Colorado and National Institute of Standards and Technology, Boulder, Colorado 80309, USA. hvparks@sandia.gov
Physical Review Letters
|September 28, 2010
Summary
Scientists precisely measured the Newtonian constant of gravitation (G) using interferometry and pendulum masses. The new G value agrees with older data but differs from recent CODATA recommendations.
Area of Science:
- Fundamental Physics
- Metrology
Background:
- The Newtonian constant of gravitation (G) is a fundamental constant in physics.
- Accurate determination of G is crucial for testing gravitational theories and understanding the universe.
- Previous measurements of G have shown significant discrepancies, leading to ongoing research.
Purpose of the Study:
- To determine a precise value for the Newtonian constant of gravitation (G).
- To compare the new G value with existing CODATA recommendations and other experimental results.
Main Methods:
- Interferometric measurement of the change in spacing between two free-hanging pendulum masses.
- Utilizing large tungsten source masses to generate a measurable gravitational field.
Main Results:
- A new value for G was determined as (6.67234±0.00014)×10⁻¹¹ m³ kg⁻¹ s⁻².
- This result shows good agreement with the 1986 CODATA value.
- The determined G value differs from some recent experimental results and the latest CODATA recommendation.
Conclusions:
- The study provides a new, precise measurement of the Newtonian constant of gravitation.
- The findings highlight persistent discrepancies in G measurements, indicating areas for further investigation in experimental gravity.
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