[fitsbits] Re: leap second alert

[Clive Page]

In article <19991216131819.A21354 at ucolick.org>,
Steve Allen  <sla at ucolick.org> wrote:

>Look at the activity of the IAU over the past few decades and the
>proliferation of new, subtly-better-defined timescales.  I'm not privy
>to the actual discussions of the committees, but it looks like the
>astronomy community learned a lesson in 1925:

It just happens that I was present at the IAU meeting at Brighton where the
leap-second proposal was adopted.   It was fascinating to me as a student
because it was the only session of the supposedly bilingual symposium where
there were actually contributions in French (presumably because of the
number of contributors from Bureau Internationale de l'Heure).  I was
glad of the language practice.   My recollection is that the longest and
most acrimonious debate was over the question of whether UTC should be
allowed to drift from UT2 by 0.6 or 0.7 seconds before the IERS was
required to insert another leap second.   In hindsight one wonders why
anyone cared about such details, since in practice the leap second tends to
be inserted when the difference exceeds about half a second.   

So it occurs to me to wonder what would happen if the IAU simply passed a
resolution increasing the maximum offset from 0.7 (or is it 0.6 seconds?)
to, say, 300 seconds, and as a result the IERS gave up inserting leap 
seconds.  It wouldn't affect the legal situation, would it?  It wouldn't
affect astronomers, navigators, etc, since anyone who needs precise time
understands the meaning of the existing time scales, and can choose which
one suits them best, and can compute UT1/UT2/sidereal time or whatever
they need using standard techniques. The general public would surely not
notice for a long time the fact that sunset or sunrise was drifting away
at the rate of a few seconds per decade.   Can anyone see any ill effects?

-- 
-- 
Clive Page,
Dept of Physics & Astronomy,               
University of Leicester.