Re: [LEAPSECS] FITS and the crafting of standards

From: Roger Stapleton <jrs_at_ST-ANDREWS.AC.UK>
Date: Wed, 29 Jan 2003 11:21:06 +0000 (GMT)

Can I muddy the waters with some facts/evidence I have collected recently?
(if your answer is "no" - then hit 'delete' now ;-)

First where do I fit in this debate. I am the systems manager for the
Astronomy group at St.Andrews University. We run a small observatory with
4 telescopes, a couple of Meade LX200s, a 1980s built scope on a ~1900
Grub Parsons mount (where setting is done with large metal rings with
painted scales - too new for Victorian engraved brass, too old for digital
encoders, very nice to use) and a 1m class Schmidt-cass built on-site in
the 1960s. When this discussion first came up I was about to re-re-write
my code for the digital setting circles that have been added to the 1m
telescope, and this needs a time feed - UTC does nicely but if it going to
change I want to know.

Over the past year or two I have given a talk entitled "What time is it?"
to local Astronomical Societies. This is a quick romp from sundials giving
12 'hours' sunrise to sunset to TAI, UTC, TDT, TDB, LST, etc. with a bit
about the moon slowing us down. As part of this I do a check on the
accuracy of the timekeeping of the audience. The full range for the
audience is usually plus/minus 20secs with ~25% in the +/-5 secs range. I
had one gentleman who was happily 2 mins slow - good enough for catching
an Edinburgh bus, he claimed! Thus we have a very rough measure of the
accuracy of the interested man-in-the-street timekeeping.

Yesterday morning over a cup of coffee I floated the question of
leapseconds and their abolition passed a couple of friends in the
University IT Services dept. One quickly decided that leapseconds were
the obvious solution, then realised we have them, and wondered what the
problem was. The other, thought for a bit, then decided that decoupling
time from from the rotation of the earth was a bit more philosophical than
technical and was the sort of world cultural heritage thing that should
not be tinkered with.

A slight worry I have is what the popular media would make of it if they
decided that "scientists" were going to mess about with time. Yet more
anti-science in the media :(

Sorry nothing posative in this - but then users of clock-on-the-wall time
are always going to be a problem.


Roger Stapleton
University of St.Andrews, School of Physics & Astronomy
North Haugh, St.Andrews, Fife. KY16 9SS
Phone 01334-463141 Fax 01334-463104
Received on Wed Jan 29 2003 - 03:21:15 PST

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