Systematic error

Statistics

Acceleration

Detection limit

Physics

Torsion pendulum clock

Gravitation

Angular acceleration

Programming language

Standard deviation

Acoustics

Value (mathematics)

Constant (computer programming)

Mathematics

Computer science

Relative standard deviation

Quantum mechanics

Swing

Gravitational acceleration

Classical mechanics

Gravitational constant

Nature

The Newtonian gravitational constant, G, is one of the most fundamental constants of nature, but we still do not have an accurate value for it. Despite two centuries of experimental effort, the value of G remains the least precisely known of the fundamental constants. A discrepancy of up to 0.05 per cent in recent determinations of G suggests that there may be undiscovered systematic errors in the various existing methods. One way to&nbsp;resolve this issue is to measure G using&nbsp;a number of methods that are unlikely to involve the same systematic effects. Here we report two independent determinations of G using torsion pendulum experiments with the time-of-swing method and the angular-acceleration-feedback method. We obtain G values of 6.674184 × 10−11 and 6.674484 × 10−11 cubic metres per kilogram per second squared, with relative standard uncertainties of 11.64 and 11.61 parts per million, respectively. These values have the smallest uncertainties reported until now, and both agree with the latest recommended value within two standard deviations. The Newtonian gravitational constant is measured with two independent methods, yielding results with relative standard uncertainties of 11.6 parts per million—the lowest uncertainty reported until now.

Measurements of the gravitational constant using two independent methods