Re: [LEAPSECS] Torino meeting and implications of international time >> UT1

From: Rob Seaman <seaman_at_NOAO.EDU>
Date: Thu, 5 Jun 2003 11:09:38 -0700 (MST)

> William Klepczynski: In safety-critical navigation systems, leap seconds
> will over time cause catastrophic system failures that will cost many
> lives. This long-term risk should justify even considerable one-off
> expenses to fix permanently the problem of a commonly used non-uniform
> precision timescale.

Perhaps this is true. It may also be true that such safety critical
navigation systems implicitly rely on civil time being based on GMT.
This is the reality of civil time that has applied since the 19th
century. I can imagine innumerable ways in which software systems,
hardware systems or the operational procedures for navigation
(either terrestrial or celestial) might depend on UTC ~= GMT.

Why should we accept any anecdotal handwaving on this subject? Not
only would acting on such flimsy reasoning be intellectually bankrupt,
it might actually be criminal. If any individual has hard evidence to
suggest that specific systems or procedures are intrinsically subject
to failure due to leap seconds - and equally importantly - are *not*
subject to failure from breaking the approximation of GMT by UTC,
well then, let that evidence be presented. It certainly has not been
presented previously on this mailing list, and it sounds like such
wasn't presented in Torino either.

Were any representatives of the air traffic control or other safety
critical navigational communities present at the meeting? Such input
should be sought up front, not brought in at the end to justify a
conclusion that "Leap seconds must die!" that was already formed
prior to Y2K.

Rob Seaman
National Optical Astronomy Observatory
Received on Thu Jun 05 2003 - 11:09:57 PDT