Fundamental Constants Data Center
Overview 
Program Directions 
Major Technical Highlights
Overview
The FCDC supports the NIST mission by:
 providing an international information center on the fundamental constants;
 periodically providing sets of recommended values of the constants for
international use;
 administering the NIST Precision Measurement Grant (PMG) Program;
 providing the editorship of the Journal of Research of the National
Institute of Standards and Technology; and
 interpreting the International System of Units (SI) for the United States.
Program Directions
 Information Center and Constants Adjustments. Maintain a fundamental
constants library, a Web bibliographic database, respond to inquiries, and
carry out the next Committee on Data for Science and Technology (CODATA)
leastsquares adjustment of the values of the constants.
 Precision Measurement Grants. Continue to fund proposals of the
highest quality and that provide maximum benefit to NIST.
 Fundamental Constants Theory. Create an atomic theory bibliographic
database and do calculations where needed for the theory used in evaluation of
the fundamental constants.
 SI Units. Generate and disseminate publications related to the SI.
 Measurement Uncertainty. Under the auspices of the international
Joint Committee for Guides on Metrology (JCGM), generate guides on expressing
measurement uncertainty.
Major Technical Highlights
 Constants Wall Chart and Wallet Cards. Concurrent with the NIST
centennial, thousands of copies of a wall chart and a wallet card giving
subsets of the 1998 CODATA recommended values of the fundamental constants of
physics and chemistry (the most current) were distributed to physicists,
chemists, other scientists, engineers, and students throughout the world.
 Centennial Issue of NIST Journal of Research. To commemorate the
NBS/NIST centennial on March 3, 2001, the JanuaryFebruary 2001 issue
(Vol. 106, No. 1) of the Journal of Research of the National
Institute of Standards and Technology was published as the Centennial Issue
under the title "NBS/NIST — 100 Years of Measurement." The
370 page issue contains 12 articles, all centered on measurement
recognizing that since its founding in 1901, NBS/NIST has served as the Nation’s
National Metrology Institute (NMI). Indeed, metrology has been the foundation
upon which the institution has rested for the first 100 years of its
existence. The Centennial Issue is available on the Web at
http://www.nist.gov/jres.
 Theory of the Hydrogen Atom. Precise theoretical predictions of the
properties of hydrogen are important, not only to test our understanding of
this basic atom, but also to provide information on the fundamental physical
constants, such as the Rydberg constant. Over the past several years, a
NISTled project has carried out a precise computation of the most basic
quantum electrodynamic (QED) effect in the spectrum of hydrogen, namely the
radiative process in which the atom emits and then reabsorbs a photon (the
quantum of electromagnetic radiation). This process results in shifts of the
atomic energy levels, which, in turn, determines the frequencies of light that
are emitted and absorbed in experiments. The calculation was carried out for
the 1S, 2S, and 2P states of hydrogen. By employing intensive, highperformance
parallel computation, with CPU times of the order of months, the project has
led to a reduction of the uncertainty in the onephoton QED effect by over
three orders of magnitude. This work was the result of a collaboration between
NIST and the Technical University of Dresden, Germany, and is described as a
"spectacular success" in Physics Reports 342, 63 (2001).
 New Publication on the SI. The 2001 Edition of NIST Special
Publication (SP) 330, The International System of Units (SI)
is now available. It is the U.S. version of the English text of the seventh
edition (the most recent) of the definitive international reference on the SI,
the modern metric system, published in 1998 by the International Bureau of
Weights and Measures (BIPM) under the title Le Système International
d’Unités (SI). However, the 2001 Edition of SP 330 also
incorporates the contents of Supplément 2000:
additions et corrections à la 7^{e} édition
(1998) published by the BIPM in June 2000. The 2001 edition of
SP 330 replaces its immediate predecessor, the 1991 edition, which was
based on the sixth edition of the BIPM SI publication.
 New Precision Measurement Grants. Two new NIST Precision Measurement
Grants have been awarded. One was made to Prof. Mohideen of the University
of California at Riverside for the project entitled "Precision
Measurements of the Casimir Force Using an Atomic Force Microscope." The
aim of the research supported by this grant is to make high precision
measurements of the Casimir force between small metallic objects. The Casimir
force is the result of the effect that the objects have on the electromagnetic
fluctuations in the vacuum in the space between them. This force can be
significant at distances less than 100 nm, and so it plays an important role in the mechanical properties of artificial microstructures. The proposed research will increase the precision of measurements of the Casimir force by over a factor of 10,000 and will measure the temperature dependence of the force.
The other grant was made to Prof. Schoelkopf of Yale University for
the project entitled "Development of an ElectronCounting Ammeter."
The aim of the research supported by this grant is to make a device to measure
electric current (an ammeter) based on measurement of the frequency of voltage
oscillations across a tunnel junction that allows only one electron at a time
to pass through. Such a device could only measure small currents, however a
sufficient number in parallel could measure a current that would be large
enough to allow fundamental tests of present day resistance and voltage
standards based on quantum devices. An electroncounting ammeter is more likely
to be scalable to such a use than the analogous single electron pumps which
already exist.
Overview 
Program Directions 
Major Technical Highlights
