Abstract
The need to consider time scales in a relativistic framework appeared more than 20 years age following the progress of atomic time standards. After long discussions, this led the IAU to define, in 1976, time scales which were designated, in 1979, as Terrestrial Dynamical Time (TDT) and Barycentric Dynamical Time (TDB). But soon afterwards difficulties in the interpretation of the definitions of TDT and TDB arose. It appeared that the source of these difficulties was the lack of a global approach to space-time reference systems. This point of view, first voiced by J. Lieske, gained acceptance. At the very beginning of the work of the WGRS Sub-Groups on Frames and Origins (SGFO) and on Time (SGT), it became clear the the primary mission of the SGFO and SGT was to jointly prepare general recommendations on space-time references on which they could base their specific recommendations.
I start by general remarks on the background of the recommendations on space-time references which are submitted to you.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Argue, N., 1991, “Hipparcos: its link to extragalactic reference frame”, in Reference systems, IAU Coll. 127,J.A. Hughes, C.A. Smith and G.H. Kaplan (eds.), US Naval Observatory Publ., p.63.
Capitaine, N. and Gontier, A.M., 1991, “Procedures for VLBI estimates of the Earth rotation parameters using the non-rotating origin”, in Reference systems, IAU Coll. 127, J.A. Hughes, C.A. Smith and G.H. Kaplan (eds.), US Naval Observatory Publ., p.77.
Guinot, B., 1992, this volume.
Kovalevsky, J., 1991. “Preliminary report of the work of the subgroup coordinateframes and origins”. in Reference systems, IAU Coll. 127, J.A. Hughes, C.A. Smith and G.H. Kaplan (eds.), US Naval Observatory Publ., p.17.
Recommendations of the working group on reference systems, in Reference systems, IAU Coll. 127. J.A Hughes, C.A. Smith and G.H. Kaplan (eds.),US Naval Observatory Publ., p.408.
References
Brumberg, V.A., 1991, “Relativistic Hierarchy of Reference Systems and Time Scales,” Proc. IAU Colloq. No. 127, Eds. J.A. Hughes, C.A. Smith and G.H. Kaplan, p36, USNO, Washington.
Fukushima T., Fujimoto M.-K., Kinoshita H., and Aoki S., 1986, “A System of Astronomical Constants in the Relativistic Framework,” Celest. Mech. 38, 215.
Klioner S.A., “The Problem of Clock Synchronization: A Relativistic Approach,” Celest. Mech. (in press).
Soffel M.H., and Brumberg V.A., “Relativistic Reference Frames and Time Scales: Questions and Answers,” Celest. Mech. (in press).
References
Ludwig Boltzmann (1912) Vorlesungen ueber Gastheorie, II. Teil. Johannn Ambrosius Barth, Leipzig. See p. 257 (paragraph 90): B. argues that in a closed universe there must eventually be as many regions where entropy increases as regions where it decreases. “Therefore” there is no preferred direction of time, as there is no up or down in space. Since this was written long before relativity theory (1912 is the date of a second edition) it is remarkable that B. clearly states a concept of time which is radically different from Newton’s. However, the reasoning is not correct because it tacitly presupposes a time of reference against which one can state whether anything increases or decreases. The reasoning assumes tacitly what it tries to disregard: that time is a primitive concept.
Louis Marton (ed.) (1977) Advances in Electronics and Electron Physics. Chapter 2. Academic Press NY. ISBN 0-12-014644-4 LCC# 49–7504 Gives an overview of time measurement with many references.
C.O. Alley, “Introduction to Some Fundamental Concepts of General Relativity and to Their Required Use in Some Modem Timekeeping Systems,” Proceedings of the Thirteenth Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, pp. 687–727, 1981 (NASA Conference Publication 2220).
J.C. Hafele and R.E. Keating, “Around the World Atomic Clocks,” Science, vol. 177, pp. 166–170, 14 July 1972.
C.O. Alley, “Relativity and Clocks,” Proceedings of the 33rd Annual Symposium on Frequency Control, pp. 4–39A, 1979.
I.I. Shapiro, “Down to Earth Relativity,” Proceedings of the Tenth Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, pp. 549–568, 1978 (NASA Technical Memorandum 80250).
N. Ashby and D.W. Allan, “Practical Implications of Relativity for a Global Coordinate Time Scale,” Radio Science, vol. 14, pp. 649–669, 19791979. This is a particularly important paper for timing applications: it discusses many specific examples, from clock trips to satellite time comparisons.
N. Ashby and D.W. Allan, “Coordinate Time on and near the Earth,” Physical Review Letters, vol. 53, p. 1858, 1984.
C.O. Alley, et al., “Differential Comparison of the One-Way Speed of Light in the East-West and West-East Directions on the Rotating Earth,” Proceedings of the Twentieth Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, pp. 261–286, 1988 (available from the U.S. Naval Observatory). For full details of this interesting experiment see [19].
D.W. Allan and N. Ashby, “Coordinate Time in the Vicinity of the Earth,” in International Astronomical Union Symposium No. 114: Relativity in Celestial Mechanics and Astrometry, J. Kovalevsky and V.A. Bromberg, Eds., pp. 299–313, Dordrecht, Holland: D. Reidel Pub. Co., 1986.
D.W. Allan, M.A. Weiss, and N. Ashby, “Around-the-World Relativistic Sagnac Experiment,” Science, vol. 228, pp. 69–70, 5 April 1985.
J.B. Thomas, “A Relat ivistic Analysis of Clock Synchronization.” Proceedings of the Sixth Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting pp. 425–439, 1974 (available from the U.S. Naval Observatory).
Comité Consultatif pour la Définition de la Seconde, “Declaration et Note”, 9e Session, Bureau International des Poids et Mesures (BIPM), PavilIon de Breteuil, F-92310 Sèvres, France, 1980.
Recommendations and Reports of the CCIR, “Relativistic Effects in a Terrestrial Coordinate Time System”, ITU Geneva, Report 439–4, Volume VII, pp. 134–138, 1986. A slightly modified version will be published in the “Green Book” of the XVIIth Plenary Assembly, Diisseldorf, Germany, 1990.
G.M.R. Winkler and T. van Flandem, “Ephemeris Time, Relativity, and the Problem of Uniform Time in Astronomy”, Astron. J. 82, pp. 84–92, January 1977.
B. Guinot and P.K. Seidelmann, “Time Scales: their history, definition and interpretation,” Astron. Astrophys. vol. 194, pp. 304–308, 1988.
In I.A.U. Colloquium 127 Reference Systems, Virginia Beach, Virginia, USA, 14–20 October 1990. Eds. J. A. Hughes, G. Kaplan, and C. Smith, U.S. Naval Observatory 1991.
References
McCarthy, D.D., 1989, IERS Standards, IERS Technical Note 3, Observatoire de Paris, Paris
Guinot, B., 1979, “Basic problems in the kinematics of the rotation of the Earth”, in Time and the Earth’s Rotation, D.O. McCarthy and J.D. Pilkington (eds), D. Reidel Publishing Company.
Editor information
Rights and permissions
Copyright information
© 1992 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Hughes, J.A. (1992). Reference systems: What are they & what’s the problem?. In: Bergeron, J. (eds) Highlights of Astronomy. International Astronomical Union, vol 9. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-2828-5_5
Download citation
DOI: https://doi.org/10.1007/978-94-011-2828-5_5
Publisher Name: Springer, Dordrecht
Print ISBN: 978-0-7923-1916-0
Online ISBN: 978-94-011-2828-5
eBook Packages: Springer Book Archive