Variation in the Speed of Rotation of the Earth since June 1955

Abstract

The Editors do not hold themselves responsible jO'I' opinions expressed by their cO'l'Tespondents. No notice is taken of anonymous communications. Variation in theSpeed of Rotation of the Earth since June 1955 TIME and frequency comparisons have. been ma.de since June 1955 between the National Physical Laboratory, Teddington, and the U.S. Naval Observatory, Washington, with the ultimate purpose of establishing the value of the transition frequency of cresiuro, {4,0) ~ {3,0), in terms of the second of Ephemeris Time based on the orbital motion of the Moon 1 , 2 • The second of Ephemeris Time is being determined at the Naval Observatory from photographic observations of the Moon, and will be reported on later. 9192631950 vu 900

Comparing Relativistic Theories Against Observed Perihelion Shifts of Icarus and Mercury

“…Even though TAI was set to be identical with UT on 0 January 1958, TAI steadily diverged ahead of UT. The very team that so precisely calibrated the SI second to the lunar ET second reported that the UT second was larger than the lunar ET second by using the same calibration data from 1955 through 1958 [30,31].…”

“…The very team that precisely calibrated the lunar ET second for the SI (or atomic) second later reported from the same data of lunar observations, cesium frequencies and UT observations that the UT second was longer than the lunar ET second [30,31]. The calibration for the cesium clock to the ILE started January 1955 and lasted 3 ¼ years.…”

“…The calibration for the cesium clock to the ILE started January 1955 and lasted 3 ¼ years. (For brevity, only [30] will be discussed.) Figure 1 illustrates that the average UT second is longer than the ET second as compared to the standard cesium frequency, which is defined as 9192631770 cycles [27].…”

31. Commission de L’Heure

“…Atomic and molecular standards of frequency are being used to control standard frequency transmission and to study changes in the speed of rotation of the Earth. The cesium standard built by L. Essen and J. V. L. Parry at the National Physical Laboratory, Teddington, in 1955 has an apparent stability of 1 part in io 10 [1]. A cesium standard, called the Atomichron, is being built commercially in the United States.…”

“…Naval Observatory, Washington. The results were published in two papers [1,2]. The frequency obtained is 9 192 631 770 cycles per second.…”