CODATA and the Newtonian Gravitational Constant

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CODATA and the Newtonian Gravitational Constant
Newtonian constant of gravitation workshop NIST 9
- 10 October, 2014

David B. Newell National Institute of Standards
and Technology Gaithersburg, MD, USA
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Values of G
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Values of G
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Outline

• CODATA
• Formation
• Role
• FC adjustment methodology
• CODATA LSA of G data

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Determination of Fundamental Constants before
CODATA

• Method of Least Squares (LSA)
• Nouvelles méthodes pour la détermination des
  orites des comètes, Adrien-Marie Legendre,
  Paris, publisher F. Didot, (1805)
• Theoria motus corporum coelestium in
  sectionibus conicis solem ambientium, C. F.
  Gauss, Hamburg S. F. Perthes and I. H. Besser,
  (1809)
• Théorie Analytique des Probabilités, P. S.
  Laplace, marquis de, vol. II, Paris Ve.
  Courcier, (1812)
• Theoria Combinationis Observationum Erroribus
  Minimis Obnoxiae, in Commentationes societatis
  regiae scientiarum Gottingensis recentiores, Vol.
  v., C. F. Gauss, Göttingen Royal Society of
  Göttingen, pp. 33-62 (1823)
• Adjustments of the Constants
• Probable Values of the General Physical
  Constants, R. T. Birge, Rev. Mod. Phys. 1(1),
  1-73 (1929)

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Determination of Fundamental Constants before
CODATA

• Subsequent determinations
• Our Knowledge of the Atomic Constants F, N, m,
  and h in 1947, and of Other Constants Derivable
  Therefrom, J. W. M. DuMond and E. R. Cohen, Rev.
  Mod. Phys. 20(1), 82-108 (1948) E 21(4), 651-652
  p. (1949)
• A Re-Evaluation of the Fundamental Atomic
  Constants, J. A. Bearden and H. M. Watts, Phys.
  Rev. 81(1), 73-81 (1951)
• Least-Squares Adjustment of the Atomic
  Constants, 1952, J. W. M. DuMond and E. R.
  Cohen, Rev. Mod. Phys. 25(3), 691-708 (1953)
• Present Status of the Atomic Constants, J. A.
  Bearden, M. D. Earle, J. M. Minkowski, and J. S.
  Thomsen, Phys. Rev. 93(3), 629-630 (1954)
• A Survey of Atomic Constants, J. A. Bearden and
  J. S. Thomsen, Nuovo Cimento Suppl. 5(2), 267-360
  (1957)
• A survey of the systematic evaluation of the
  universal physical constants, R. T. Birge, Nuovo
  Cimento Suppl. 6(1), 39-67 (1957)
• Résumé of Atomic Constants, J. A. Bearden and
  J. S. Thomsen, Am. J. Phys. 27(8), 569-576 (1959)
• Status of Knowledge of the Fundamental Constants
  of Physics and Chemistry as of January 1959, J.
  W. M. DuMond, Ann. Phys. (N.Y.) 7(4), 365-403
  (1959)
• Our Knowledge of the Fundamental Constants of
  Physics and Chemistry in 1965, E. R. Cohen and
  J. W. M. DuMond, Rev. Mod. Phys. 37(4), 537-594
  (1965)
• Determination of e/h, Using Macroscopic Quantum
  Phase Coherence in Superconductors Implications
  for Quantum Electrodynamics and the Fundamental
  Physical Constants, B. N. Taylor, W. H. Parker,
  and D. N. Langenberg, Rev. Mod. Phys. 41(3),
  375-496 (1969)

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Formation of CODATA

• 1966 ICSU establishes the Committee on Data for
  Science and Technology (CODATA)
• To strengthen international science for the
  benefit of society by promoting improved
  scientific and technical data management and use

icsu.org
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Formation of CODATA

• 1966 ICSU establishes the Committee on Data for
  Science and Technology (CODATA)
• To strengthen international science for the
  benefit of society by promoting improved
  scientific and technical data management and use

icsu.org
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CODATA Adjustments

• The 1973 least-squares adjustment of the
  fundamental constants, E. R. Cohen and B. N.
  Taylor, J. Phys. Chem. Ref. Data 2(4), 663-734
  (1973)
• The 1986 adjustment of the fundamental physical
  constants, E. R. Cohen and B. N. Taylor, Rev.
  Mod. Phys. 59(4), 1121-1148 (1987)
• CODATA recommended values of the fundamental
  physical constants 1998, P. J. Mohr and B. N.
  Taylor, Rev. Mod. Phys. 72(2), 351-495 (2000)
• CODATA recommended values of the fundamental
  physical constants 2002, P. J. Mohr and B. N.
  Taylor, Rev. Mod. Phys. 77(1), 1-107 (2005)
• CODATA recommended values of the fundamental
  physical constants 2006, P. J. Mohr, B. N.
  Taylor, and D. B. Newell, Rev. Mod. Phys. 80(2),
  633-730 (2008)
• CODATA recommended values of the fundamental
  physical constants 2010, P. J. Mohr, B. N.
  Taylor, and D. B. Newell, Rev. Mod. Phys. 84(4),
  1527-1605 (2012)

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Who are they, anyway?

• F. Cabiati, Istituto Nazionale di Ricerca
  Metrologica, Italy
• J. Fischer, Physikalisch-Technische
  Bundesanstalt, Germany
• K. Fujii, National Metrology Institute of Japan,
  Japan
• S. G. Karshenboim, D. I. Mendeleyev Institute of
  Metrology, Russia
• E. de Mirandés, Bureau International des Poids et
  Mesures, France
• P. J. Mohr, National Institute of Standard and
  Technology, USA
• D. B. Newell, National Institute of Standard and
  Technology, USA
• F. Nez, Laboratoire Kastler-Brossel, France
• K. Pachucki, University of Warsaw, Poland
• T. J. Quinn, CBE FRS, France
• B. N. Taylor, National Institute of Standard and
  Technology, USA
• C. Thomas, Bureau International des Poids et
  Mesures, France
• B. M. Wood, National Research Council, Canada
• Z. Zhang, National Institute of Metrology, China

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Role of CODATA TGFC

• Provide the best values of the constants based on
  all relevant data available
• Smallest possible uncertainties
• Unlike other data comparison analysis (i.e. - key
  comparisons) - no safety factors

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Role of CODATA TGFC

• Provide the best values of the constants based on
  all relevant data available
• Smallest possible uncertainties
• Unlike other data comparison analysis (i.e. - key
  comparisons) - no safety factors

• Challenge hard decisions
• Discrepant data
• Limited data
• Lack of redundancy and independent confirmation
• Possibility of new physics

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LSA Methodology

• Collect all data
• Older data form previous LSAs
• Include new data since the last LSA
• Preliminary review of the data
• Check for up-to-date input and corrections, full
  uncertainty analysis, and internal consistency
• Select acceptable data by lowest uncertainties
• Assess relation with other input data
• Supersedes previous results?
• Covariance - sort by common uncertainty
  components

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LSA Methodology (cont.d)

• Run mini LSA for each of the main constants and
  use standard statistic tools to investigate
  goodness of fit
• Chi squared (c2), Probability of reduced c2,
  Birge ratio RB, Maximum Normalized Residuals
  (MNR), Maximum Normalized Difference (MND), etc.
• Adjust expansion factors, include/exclude
  specific data
• 1 self sensitivity test
• Run final multi-variant LSA, argue, re-run LSA,
  etc.
• Minimize total disagreement

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1973 CODATA Least-Squares Adjustment of G
1930, Heyl
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1973 CODATA Least-Squares Adjustment of G
1930, Heyl
G 6.6720(41) 10-11 m3 s-2 kg-1 (615 ppm)
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1986 CODATA Least-Squares Adjustment of G
CODATA 1973
1969, Rose et al.
1972, Pontikis
1976, Karagioz et al.
1979, Sagitov et al.
1982, Luther and Towler
CODATA 1986
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1986 CODATA Least-Squares Adjustment of G
CODATA 1973
1969, Rose et al.
1972, Ponkitis
1976, Karagioz et al.
1979, Sagitov et al.
1982, Luther and Towler
CODATA 1986
G 6.67259(85) 10-11 m3 s-2 kg-1 (128 ppm)
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1998 CODATA Least-Squares Adjustment of G
CODATA 1986
PTB-95
LANL-97
TRD-98
JILA-98
HUST-99
MSL-99
BIPM-99
UZur-99
Uwup-99
CODATA-98
G 6.673(10) 10-11 m3 s-2 kg-1 (1500 ppm)
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2002 CODATA Least-Squares Adjustment of G
CODATA 1986
CODATA-98
LANL-97
TRD-98
HUST-99
UWash-00
BIPM-01
Uwup-02
UZur-02
MSL-03
CODATA-02
G 6.6742(10) 10-11 m3 s-2 kg-1 (150 ppm)
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2006 CODATA Least-Squares Adjustment of G
CODATA-02
TRD-96
LANL-97
UWash-00
BIPM-01
Uwup-02
MSL-03
HUST-05
UZur-06
CODATA-06
G 6.67428(67) 10-11 m3 s-2 kg-1 (100 ppm)
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2010 CODATA Least-Squares Adjustment of G


?2 208.6 Probability 0.0000 Birge
4.57 MNR 10.73 MND 9.93
???
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2010 CODATA Least-Squares Adjustment of G


Remove Two Outliers
?2 40.1 Probability 0.0000 Birge
2.24 MNR 3.67 MND 3.63
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2010 CODATA Least-Squares Adjustment of G


Remove 6 of 11
?2 2.00 Probability 0.74 Birge 0.71 MNR
1.31 MND 1.27
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2010 CODATA Least-Squares Adjustment of G


Expansion Factor 14
?2 1.06 Probability 1.00 Birge 0.33 MNR
0.77 MND 0.71
G 6.67384(80) 10-11 m3 s-2 kg-1 (120 ppm)
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2014 CODATA Least-Squares Adjustment of G
CODATA-06
NIST-82
TRD-96
LANL-97
UWash-00
BIPM-01
Uwup-02
MSL-03
HUST-05
UZur-06
HUST-09
JILA-10
CODATA-10
BIPM-14
UFlorence-14
UCIrving-14
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Treatment of Discrepant Data

• Expand all uncertainties for a satisfactory ?2

• Exclude incompatible data and expand final
  uncertainty

• Exclude incompatible data, no expansion

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Treatment of Discrepant Data

• Expand all uncertainties for a satisfactory ?2

• Exclude incompatible data and expand final
  uncertainty

• Exclude incompatible data, no expansion

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2010 CODATA Values
physics.nist.gov/constants
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Searchable Bibliography
http//physics.nist.gov/cuu/Constants/Citations/Se
arch.html
http//bach.nist.gov/cuu/Constants/Citations/Searc
h.html