Newton's constant and the twenty-first century laboratory.
The main aim of this paper is to describe the problems that confront experimentalists who attempt to determine Newton's constant of gravitation, G. I will motivate this work by discussing the role of Newton's constant of gravitation in classical physics and recent ideas as to its role in quantum physics. I will then discuss some key aspects of a precision determination of G. This will include criteria for the selection of the detector of the gravitational torque from the point of view of random uncertainties due to read-out noise, thermal and vibrational noise. Another important factor in precise determinations of G is the control of systematic effects (type B uncertainties) such as those due to uncertainties in absolute calibration of the gravitational torque, density homogeneity of source masses and length metrology. I will illustrate the discussion using the determination of G currently underway at the International Bureau of Weights and Measures in France, and describe other experimental configurations that have been used in the past or are being currently developed.
Speake
Clive C
CC
University of Birmingham, Birmingham B15 2TT, UK. c.c.speake@bham.ac.uk
D006112:Gravitation; D007394:International System of Units / Q000592:standards*; D038622:Internationality; D007753:Laboratories / Q000592:standards* / Q000639:trends; D010825:Physics / Q000592:standards*; D012015:Reference Standards; D012016:Reference Values; D015203:Reproducibility of Results; D012586:Science / Q000592:standards*; D012680:Sensitivity and Specificity