Time Scales

  title={Time Scales},
  author={L Essen},
  pages={161 - 165}
  • L Essen
  • Published 1968
  • Physics
  • Metrologia
Time scales have traditionally provided the time of day and the season of the year, as well as time interval, and if it is to be of universal use the atomic scale must be coordinated with astronomical scales. Two major steps in the coordination have already been taken: the atomic unit has been defined in terms of the second of Ephemeris Time, and the scales were made to agree on 1st January 1958. If the rotation of the Earth were constant the scales would continue to agree, but because of the…