English

Fundamental units: physics and metrology

Physics Education 2017-08-23 v1 General Physics

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 cc and quantum of action hh. On the other hand, the poor precision of gravitational constant GG, which is widely believed to define the ``cube of theories'' and the units of the future ``theory of everything'', does not allow to use GG 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.

Keywords

Cite

@article{arxiv.physics/0310069,
  title  = {Fundamental units: physics and metrology},
  author = {L. B. Okun},
  journal= {arXiv preprint arXiv:physics/0310069},
  year   = {2017}
}

Comments

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)