scholarly journals Recommending a value for the Newtonian gravitational constant

2014 ◽  
Vol 372 (2026) ◽  
pp. 20140029 ◽  
Author(s):  
Barry M. Wood
Keyword(s):  
Gravitational Constant ◽  
Present Situation ◽  
Primary Objective ◽  
Experimental Results ◽  
Task Group ◽  
Fundamental Constants ◽  
Conversion Factors ◽  
A Value ◽  
Self Consistent ◽  
Newtonian Gravitational Constant

The primary objective of the CODATA Task Group on Fundamental Constants is ‘to periodically provide the scientific and technological communities with a self-consistent set of internationally recommended values of the basic constants and conversion factors of physics and chemistry based on all of the relevant data available at a given point in time’. I discuss why the availability of these recommended values is important and how it simplifies and improves science. I outline the process of determining the recommended values and introduce the principles that are used to deal with discrepant results. In particular, I discuss the specific challenges posed by the present situation of gravitational constant experimental results and how these principles were applied to the most recent 2010 recommended value. Finally, I speculate about what may be expected for the next recommended value of the gravitational constant scheduled for evaluation in 2014.

The fundamental constants and theory

2005 ◽  
Vol 363 (1834) ◽  
pp. 2123-2137 ◽  
Author(s):  
Peter J Mohr
Keyword(s):  
Experimental Data ◽  
Least Squares ◽  
Science And Technology ◽  
Fundamental Constants ◽  
Conversion Factors ◽  
Self Consistent ◽  
Theoretical Predictions

The Committee on Data for Science and Technology has recently recommended a new self-consistent set of values of basic constants and conversion factors of physics and chemistry. These values are based on a least-squares analysis that takes into account all of the latest relevant experimental and theoretical information in a consistent framework. Theory plays a role, because the experimental data are compared to the corresponding theoretical predictions which are functions of the fundamental constants. The best values of the constants are taken to be those that give the best agreement between the data and these predictions, in the least-squares sense. An overview of the calculations that influence the recommended values of the constants will be given.

Expected Improvement in the Determination of G Using an X Pendulum

1997 ◽  
Vol 12 (11) ◽  
pp. 1967-1974 ◽  
Author(s):  
Kazuaki Kuroda ◽  
Mark A. Barton ◽  
Atsushi Onae ◽  
Yukinobu Miki
Keyword(s):  
Gravitational Constant ◽  
New Technique ◽  
Expected Improvement ◽  
Order Of Magnitude ◽  
Experimental Errors ◽  
A New Technique ◽  
Newtonian Gravitational Constant

We propose the application of a new technique, the X pendulum, to determine the Newtonian gravitational constant G. We evaluate the likely experimental errors for configurations realizable with existing technologies and show that improvement of the accuracy by an order of magnitude or more is possible.

scholarly journals Precision measurement of the Newtonian gravitational constant using cold atoms

Nature ◽  
2014 ◽  
Vol 510 (7506) ◽  
pp. 518-521 ◽  
Author(s):  
G. Rosi ◽  
F. Sorrentino ◽  
L. Cacciapuoti ◽  
M. Prevedelli ◽  
G. M. Tino
Keyword(s):  
Precision Measurement ◽  
Cold Atoms ◽  
Gravitational Constant ◽  
Newtonian Gravitational Constant

An Analysis of Conventional and Self-Aligned four Terminal Resistor Structures for The Determination of The Contact Resistivity from End Resistance Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Model ◽  
Contact Resistivity ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Model Based ◽  
A Value ◽  
And Diffusion

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.

scholarly journals Reflections on a measurement of the gravitational constant using a beam balance and 13 tons of mercury

2014 ◽  
Vol 372 (2026) ◽  
pp. 20140027 ◽  
Author(s):  
S. Schlamminger ◽  
R. E. Pixley ◽  
F. Nolting ◽  
J. Schurr ◽  
U. Straumann
Keyword(s):  
Gravitational Constant ◽  
Beam Balance ◽  
A Value ◽  
University Of Zurich ◽  
The University ◽  
Experimental Effort

In 2006, a final result of a measurement of the gravi- tational constant G performed by researchers at the University of Zürich, Switzerland, was published. A value of G =6.674252(122)×10 −11  m 3  kg −1  s −2 was obtained after an experimental effort that lasted over one decade. Here, we briefly summarize the measurement and discuss the strengths and weaknesses of this approach.

Measurement of the Newtonian gravitational constant based on the principle of free fall

2009 ◽  
Vol 54 (6) ◽  
pp. 1019-1025
Author(s):  
Yong Wang ◽  
XiaoPing Ke ◽  
WeiMin Zhang ◽  
HouZe Xu ◽  
HuBiao Wang ◽  
...  
Keyword(s):  
Gravitational Constant ◽  
Free Fall ◽  
Newtonian Gravitational Constant

An anomaly in the specific heat below 3 °K of copper containing hydrogen

1969 ◽  
Vol 47 (14) ◽  
pp. 1485-1491 ◽  
Author(s):  
Neil Waterhouse
Keyword(s):  
Specific Heat ◽  
Molecular Hydrogen ◽  
Pure Copper ◽  
Solid Hydrogen ◽  
Rotational State ◽  
Experimental Results ◽  
Ortho Hydrogen ◽  
Temperature Range ◽  
A Value ◽  
Heat Curve

The specific heat of copper heated in hydrogen at 1040 °C has been measured over the temperature range 0.4 to 3.0 °K and found to be anomalous. The anomaly occurs in the same temperature range as the solid hydrogen λ anomaly which, in conjunction with evidence of ortho to para conversion of hydrogen in the sample, suggests the presence of molecular hydrogen in the copper. The anomaly reported by Martin for "as-received" American Smelting and Refining Company (ASARCO) 99.999+ % pure copper has been briefly compared with the present results. The form of the anomaly produced by the copper-hydrogen specimen has been compared with Schottky curves using the simplest possible model, that for two level splitting of the degenerate J = 1 rotational state of the ortho-hydrogen molecule.Maintenance of the copper-hydrogen sample at ~20 °K for approximately 1 week removed the "hump" in the specific heat curve. An equation of the form Cp = γT + (464.34/(θ0c)3)T3 was found to fit these experimental results and produced a value for γ which had increased over that for vacuumannealed pure copper by ~2%.

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