Exton, PA (PRWEB) December 31, 2013
The American Astronautical Society (AAS) recently published “Requirements for UTC and Civil Timekeeping on Earth,” a book detailing expert opinions about the present and future course of civil timekeeping. Based on the proceedings of an international colloquium held in spring 2013, the text expands on technical research surrounding modern civil timekeeping by considering terminological, philosophical and societal requirements, in addition to scientific usage of time-of-day.
The book answers a 2012 call by the World Radiocommunication Conference of the International Telecommunication Union (ITU) to address all technical options related to the future of the civil time scale, including “some other method” which does not modify the timekeeping convention known as Coordinated Universal Time (UTC). Changing UTC was proposed by the ITU’s study group because of technical difficulties which sometimes happen when users fail to consider leap seconds. However, leap-second adjustments are needed to keep clocks synchronized with Universal Time, the modern version of Greenwich Mean Time. Such astronomical timekeeping is basic to calendars and other human systems of dating, but today’s precise atomic frequency standards operate at a slightly different rate than the rotation of the Earth relative to the sky.
Based on the book’s findings, the distribution of an additional atomic time standard without leap seconds appears to be a promising alternative to the proposal that the ITU shelved in 2012. A parallel scale—available for technical applications that need such—is an approach already adopted by navigation systems such as GPS. A parallel scale also avoids changes to existing legal systems and avoids the need for a time scale that is no longer coordinated with Universal Time. The International Standards Organization (ISO) dissuaded the ITU from reusing the label “UTC” for a time scale without leap seconds, because this would violate established protocols for international standards and invite confusion.
“Requirements for UTC and Civil Timekeeping on Earth” is Volume 115 of the AAS Science and Technology Series, complementing an earlier companion volume. It was edited by John H. Seago of Analytical Graphics, Inc. (AGI), Robert L. Seaman of the National Optical Astronomy Observatory, P. Kenneth Seidelmann of the University of Virginia and Steven L. Allen of UCO/Lick Observatory. The book can be purchased directly from Univelt, Inc., or through major booksellers. Preprints of the articles, discussions and original presentations are available for preview at http://futureofutc.org.