[LEAPSECS] it's WP7A week in Geneva

Steve Allen sla at ucolick.org
Fri Sep 11 01:34:04 EDT 2009


On Wed 2009-09-09T23:49:42 +0000, Poul-Henning Kamp hath writ:

> In message <E44632D3-66D3-47D3-8B7A-7D8E7245D582 at 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 <sla at 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


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