On Wed 2009-09-09T23:49:42 +0000, Poul-Henning Kamp hath writ: > In message <e44632d3-66d3-47d3-8b7a-7d8e7245d...@noao.edu>, Rob Seaman writes: > > Why leap seconds are difficult to get right for an equipment vendor > >Sam Stein, Symmetricom, Inc.
> > I hope the presentations will be posted online. > > Ask him ? Sam has been very friendly & responsive in the past. The CGSIC presentations are often posted to the web. I welcome the presentation by Sam Stein and look forward to seeing it. It has the possiblility of addressing one of the big lacunae in the whole story of UTC and abandoning leaps: Who are the stakeholders and what problems are they having? The atomic chronometer keepers have been insisting that there is some urgent need to avoid leap seconds, and to avoid more time scales, but they do not name names, they do not give examples, they simply repeat that assertion, sometimes along with the spectre of planes crashing which was first aired 40 years ago. As they say on the USENET (or is that blogosphere now?) cite or shite. Without the cite it is clear that the BIPM temporal hegemony is threatened, but it is not clear how much the rest of the world should care. What the CCIR did demonstrate by their action in 1970, and the IAU (by redefining UT1 twice in the past 30 years), and the UK Admiralty (changing GMT by twelve hours) is that a time scale defined by somebody else can be changed at their whim to have characteristics which are no longer compatible with previous uses. So the natural response from everyone whose new operational system needs an operational time scale is to say "If we use their scheme we're just SOL, for they may change it at any time in a way that breaks our system, so why not define a new time scale that suits us?" The only thing in the favor of the current ITU-R structure is that this time it has been so diplomatically circumspect that there may be no organization which could hold the current UTC definition in a condition safer against any kind of change. This has become an "Us vs. Them" situation instead of a "We the people" situation -- all of the people, not just the physicists, not just the astronomers, not just the navigators, and not just us here now, but looking forward to secure things for "our posterity". I have to suppose some leadership of that sort was present, privately, while Klepczynski acted for US DoS as he got the Galileo folks to agree to change the specified time scale for the EU navigation satellites from the original TAI to GPS time. That sort of leadership and diplomacy is not evident openly in the ITU-R process. But having typed this I seem to have echoed a Canadian actor playing a 23rd century starship captain reciting an 18th century US document on a devastated planet. This is way too Kirk-like for me, where's Spock? -- Steve Allen <s...@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory Natural Sciences II, Room 165 Lat +36.99855 University of California Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs