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Physical Measurement Laboratory /Quantum Measurement Division

Fundamental Constants Data Center

The Fundamental Constants Data Center is focused on physics relevant to the determination of values of the fundamental constants of physics and chemistry.

Activities include gathering and analyzing information for, and carrying out periodic least-squares evaluations of the constants. When necessary, new theoretical calculations are carried out to provide additional information for the adjustments. The Data Center is also involved in the development of the International System of Units, which is the basis for expressing the values of the constants. Support for research relevant to the fundamental constants and tests of basic laws of physics is provided through the Precision Measurements Grants Program.

News and Updates

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Projects and Programs

CODATA values of the fundamental physical constants

Ongoing
CODATA recommended values of the constants Database of references for data on the constants Publications: Reviews of Modern Physics ( 1998) ( 2002) ( 2006) ( 2010) ( 2014) Journal of Physical and Chemical Reference Data ( 1998) ( 2006) ( 2010) Resource Letter FC-1: The physics of fundamental
guide to the SI covers

International System of Units (SI)

Ongoing
Members of the Fundamental Constants Data Center (FCDC) participate in meetings of the Consultative Committee for Units (CCU) which advises the International Committee for Weights and Measures on matters concerning the SI. The latest meeting of the CCU, held at the BIPM in June of 2013 was attended
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Newtonian constant of gravitation international consortium

Ongoing
The disagreement calls into question our ability to measure small forces on a laboratory scale. It also raises the question of whether the Newtonian force law is a complete description of gravity at these distances. An international consortium is being formed to address this problem. The

Precision Measurement Grants Program

Ongoing
If funding is available, two new grants in the amount of $50,000 per year will be awarded for the initial period of October 1 through September 30 of the following year. Each award may be continued for up to two additional years; however, future or continued funding will be at the discretion of NIST

Publications

An introduction to the new SI

Author(s)
Peter J. Mohr, Sandra Knotts, William D. Phillips
Plans are underway to redefine the International System of Units (SI) around 2018. The new SI specifies the values of certain physical constants to define units
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Contacts

Group Leader