Fundamental units: physics and metrology

Abstract

The problem of fundamental units is discussed in the context of achievements of both theoretical physics and modern metrology. On one hand, due to fascinating accuracy of atomic clocks, the traditional macroscopic standards of metrology (second, metre, kilogram) are giving way to standards based on fundamental units of nature: velocity of light $c$ and quantum of action $h$. On the other hand, the poor precision of gravitational constant $G$, which is widely believed to define the ``cube of theories'' and the units of the future ``theory of everything'', does not allow to use $G$ as a fundamental dimensional constant in metrology. The electromagnetic units in SI are actually based on concepts of prerelativistic classical electrodynamics such as ether, electric permitivity and magnetic permeability of vacuum. Concluding remarks are devoted to terminological confusion which accompanies the progress in basic physics and metrology.

20 pages, 9 figures, LaTeX, style files included; Talk at the Seminar "Astrophysics, Clocks and Fundamental Constants" (302. WE-Heraues-Seminar, Bad Honnef, Germany, 16-18 June 2003)

References in corpus (7)

• Millisecond Pulsars as Tools of Fundamental Physics
• Oklo Constraint on the Time-Variability of the Fine-Structure Constant
• 35 Years of Testing Relativistic Gravity: Where do we go from here?
• Precision Spectroscopy of Atomic Hydrogen and Variations of Fundamental Constants
• Fundamental units: physics and metrology
• Astrophysical constraints on hypothetical variability of fundamental constants
• Cold Atom Clocks, Precision Oscillators and Fundamental Tests

Cited by in corpus (62)

• CODATA Recommended Values of the Fundamental Physical Constants: 2010
• Search for New Physics with Atoms and Molecules
• Indications of a spatial variation of the fine structure constant
• The Physics of the Intergalactic Medium
• New limit on the present temporal variation of the fine structure constant
• Experimental Tests of General Relativity: Recent Progress and Future Directions
• Precision calculation of blackbody radiation shifts for optical frequency metrology
• Constraining changes in the proton-electron mass ratio with inversion and rotational lines
• 35 Years of Testing Relativistic Gravity: Where do we go from here?
• Cold Atom Clocks, Precision Oscillators and Fundamental Tests
• Oklo Constraint on the Time-Variability of the Fine-Structure Constant
• Millisecond Pulsars as Tools of Fundamental Physics
• Astrophysical constraints on hypothetical variability of fundamental constants
• Fundamental units: physics and metrology
• Precision Spectroscopy of Atomic Hydrogen and Variations of Fundamental Constants
• 5-dimensional Brans-Dicke Theory and Cosmic Acceleration
• Breaking of the equivalence principle in the electromagnetic sector and its cosmological signatures
• Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra
• VLT/UVES constraints on the cosmological variability of the fine-structure constant
• Constraining fundamental constant evolution with HI and OH lines
• General Dynamics of Varying-Alpha Universes
• Late-time cosmology of scalar-tensor theories with universal multiplicative coupling between the scalar field and the matter Lagrangian
• The static and dynamic polarisability, and the Stark and black-body radiation frequency shifts of the molecular hydrogen ions H2+, HD+, and D2+
• Fundamental Physical Constants: Looking from Different Angles
• Constraining the Variation of the Fine Structure Constant with Observations of Narrow Quasar Absorption Lines
• Is the Quantum Hall Effect influenced by the gravitational field?
• Probing fundamental constant evolution with neutral atomic gas lines
• Superradiance in the sky
• Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD}
• Magic wavelengths in the alkaline earth ions
• Consistency tests of the stability of fundamental couplings and unification scenarios
• Entanglement Generation Using Discrete Solitons in Coulomb Crystals
• Stringent constraints on fundamental constant evolution using conjugate 18 cm satellite OH lines
• A New Option for a Search for Alpha Variation: Narrow Transitions with Enhanced Sensitivity
• Searching for deviations from the General Relativity Theory with gas mass fraction of galaxy clusters and complementary probes
• Time variation of fundamental couplings and dynamical dark energy
• Development of a relativistic coupled-cluster method for one electron detachment theory: Application to Mn IX, Fe X, Co XI and Ni XII ions
• Varying electric charge in multiscale spacetimes
• On the possibility of testing the Brane-World scenario with orbital motions in the Solar System
• Anomalously small blackbody radiation shift in Tl+ frequency standard
• Compact solid-state laser source for 1S-2S spectroscopy in atomic hydrogen
• Annexing magic and tune-out wavelengths to the clock transitions of the alkaline-earth metal ions
• Standard Model in multiscale theories and observational constraints
• Implementation and Application of the Relativistic Equation of Motion Coupled-cluster Method for the Excited States of Closed-shell Atomic Systems
• Can galaxy clusters, type Ia supernovae and cosmic microwave background rule out a class of modified gravity theories?
• RCC calculation of electric dipole polarizability and correlation energy of Cn, Nh${}^{+}$ and Og: Correlation effects from lighter to superheavy elements
• Electric dipole polarizability of group-IIIA ions using PRCC: Large correlation effects from nonlinear terms
• Oklo reactors and implications for nuclear science
• Reappraisal of the limit on the variation in $\alpha$ implied by Oklo
• Probing the time variation of fine structure constant using galaxy clusters and quintessence model
• Photoionization Broadening of the 1S-2S Transition in a Beam of Atomic Hydrogen
• Isotope shifts and relativistic shifts of Cr II for study of alpha-variation in quasar absorption spectra
• Constraints on the Variation of Physical Constants, Equivalence Principle Violation, and a Fifth Force from Atomic Experiments
• Nonlinear electrodynamics and the variation of the fine structure constant
• Redshifting of cosmological black bodies in BSBM varying-alpha theories
• Fock-space relativistic coupled-cluster calculation of hyperfine induced ${}^1{\mathbf{S}}_0\to {}^3{\mathbf{P}}_0^{\mathbf{o}}$ clock transition in Al${}^{+}$
• Fock-space perturbed relativistic coupled-cluster theory for electric dipole polarizability of one-valence atomic systems: Application to Al and In
• Quantum Trans-Planckian Physics inside Black Holes and its Spectrum
• Exploring variations in the fundamental constants with ELTs: The CODEX spectrograph on OWL
• Revised fits to $\Delta \alpha /\alpha$ in consistency with the accelerating universe
• Most precise single redshift bound to the variability of the fine-structure constant
• VLT/UVES shows no cosmological variability of alpha