[LEAPSECS] presentations from AAS Future of Time sessions

Steve Allen sla at ucolick.org
Tue Jan 14 10:05:35 EST 2014


On Tue 2014-01-14T10:48:33 +0000, Poul-Henning Kamp hath writ:

> To everybody else but the scientists who tickled the atomic clocks,

> leap seconds was an academic detail of no consequence.


Right. Most of the world had quartz crystal clocks off by seconds per
month. The ephemerides simply tabulated UT for many phenomena. The
IAU, CCIR, CCDS and CGPM approved UTC with statements effectively
saying UTC is like GMT.

Nobody was expressing any worry that a time scale where the duration
of one second was defined differently and unrelated to the duration of
one day might be a problem. They licked their wounds from the decade
of battle, trumpted their compromise as the solution for all problems,
and went on as though nothing signficant had changed.


> UTC being Coordinated was a The Big Deal, and the *only* reason why

> CCITT ever got involved in timescales: Telcos needed to schedule and

> bill across national borders.


In 1980 November the CCITT accepted UTC "as the time scale for all
other telecommunications activities". In 2007 the BIPM contributed
document 7A/51-E to the ITU-R WP7A meeting regarding Question ITU-R
236/7 saying please don't use TAI, we might even suppress it. Then in
2010 November ITU-T SG 15 recommended the use of PTP (IEEE 1588) in
ITU-T Recommendation G.8265.1, an operational time scale based on TAI.

These international agencies with multi-letter-acronym names are
still not listening to each other about the nitty gritty details.

--
Steve Allen <sla at ucolick.org> WGS-84 (GPS)
UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855
1156 High Street Voice: +1 831 459 3046 Lng -122.06015
Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m


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