[LEAPSECS] Fwd: Re: Leap second is back
Richard B. Langley
lang at unb.ca
Sat Dec 27 09:07:42 EST 2008
List members might be interested in the message below posted to the Sundial List--yes,
some of us are interested in these devices that provide "true" time ;-). Not that this
posting will likely sway current diverse and seemingly entrenched opinions of some
members (one way or the other). By the way, I must confess, that reading some of the
postings reminds me of the Dilbert cartoon strip at times. ;-) Anyway, happy holidays
-- Richard Langley
Links to The Times items:
----- Forwarded message from Frank King <Frank.King at cl.cam.ac.uk> -----
Date: Sat, 27 Dec 2008 09:15:30 +0000
From: Frank King <Frank.King at cl.cam.ac.uk>
Reply-To: Frank King <Frank.King at cl.cam.ac.uk>
Subject: Re: Leap second is back
To: Sundial List <sundial at uni-koeln.de>
On 9 December, Fred Sawyer reminded us that there
will be a leap second at the end of this month. He
suggested that the proposal to eliminate Leap Seconds
has not been adopted.
It is true that this proposal has not yet been adopted
but the proposal has certainly not been abandoned.
There was a worrying report in the London Times newspaper
of 18 December noting that the ITU is still keen to get rid
of Leap Seconds. The Times also printed a defence of the
Leap Second by David Rooney (Curator of timekeeping at the
Royal Greenwich Observatory) and a further defence by my
colleague Markus Kuhn (whose office is next to mine!).
I mentioned the report to my friend John Chambers who was
Head of the UK Time Service from 1993 to 1996 and prompted
him to write a letter to the Times giving his views.
His letter, as published, can be found at:
His letter, as sent (before the Letters Editor got hold of
it!), can be found below my signature.
Very diplomatically, he notes that it really is no business
of the ITU to mess about with Civil Time.
Unfortunately, the published version leaves out John's note
about sundials. [Do Times readers have no interest in these
Equally unfortunately, the published version leaves out the
important comment that those who want an unchanging timescale
can use GPS time. Moreover, GPS time is provided free!
==== Original Letter about Leap Seconds as sent to the Times ====
Letters to the Editor, The Times -
[This letter is sent exclusively to The Times]
Any intention to interfere with the current worldwide arrangements for
civil time by minutes, or even hours (third leader and report (page 8)
December 18, letters December 19, 20) are surely beyond the competence
of the International Telecommunications Union (ITU). The ITU's scope
extends only to time signals as broadcast. Reform of civil time is as
important as calendar reform, where the ramifications of the Vatican
initiative in 1582 took hundreds of years to settle.
Coordinated Universal Time (UTC) is a compromise which has served us well
since 1972 as the basis for time zones. It provides a timescale within one
second of mean solar time for everyday use. It has seconds markers
coincident with the more regular atomic timescale used, for example, in
GPS and deep-space navigation. The two are simply related: GPS time is
14s ahead of UTC until after the leap second at the end of this month,
then it will be 15s ahead.
Sundials are used worldwide to tell the time, requiring neither fuel nor
moving parts. Some can be read to an accuracy of better than a minute.
Traditional navigation, based on observation of sun and stars, loses less
than 400 metres in accuracy when UTC is used. However much train time-
keeping improves we can live within these limits in everyday life.
Those who need to live a precise life, or whose systems depend on there
being 60 seconds in every minute, can already use GPS time. There is no
need for another time scale.
(Mr) John Chambers
(Head of UK Time Service 1993-96)
Koskenpääntie 79, 42300 Jämsänkoski, Finland
----- End forwarded message -----
Richard B. Langley E-mail: lang at unb.ca
Geodetic Research Laboratory Web: http://www.unb.ca/GGE/
Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142
University of New Brunswick Fax: +1 506 453-4943
Fredericton, N.B., Canada E3B 5A3
Fredericton? Where's that? See: http://www.city.fredericton.nb.ca/
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