Re: [LEAPSECS] what should a time standard encompass?

From: John Cowan <jcowan_at_REUTERSHEALTH.COM>
Date: Mon, 27 Jan 2003 13:53:56 -0500 (EST)

William Thompson scripsit:

> > Because as a practical matter time-distribution protocols will never reach
> > everybody, when you consider all the civil-time clocks in the world.
> > Yet such clocks will be set, as a practical matter, from civil time. This
> > leads to a very segmented time indeed.
> From my point of view, this seems to be an argument against changing the system,
> rather than the reverse. The argument of some people seems to be that
> astronomy's problems are irrelevant, and they should just depend on distributed
> time signals to make up the lack.

Currently *everyone* (not just astronomers) has to depend on distributed
leap-second information to just know what the local civil time is. That is
a most unreasonable burden.

We can't do anything about the summer-time part of it, because that depends
on local political entities that can change their minds freely, but we
can do something about the leap seconds, viz. stop tying civil time to them.
The discrepancy between LCT and LMT is already in the multi-hour range
for some locations, and a half-hour or even an hour difference is considered
entirely normal.

> However, my point was that the burden will
> come down hardest on the much larger number of amateur astronomers and
> astronavigationalists who wouldn't necessarily have ready access to time signals
> for the ever increasing discrepency between a TAI-like time, and Earth rotation.

Compared to all the civil-time clocks in the world, the number of amateur
astronomers and astronavigationalists (nice word!) is small indeed, and
suitable low-bandwidth and high S/N communication channels already exist
for them.

> I find the argument that astronomer's objections are inconvenient, and thus
> should be just ignored, to be completely specious.

I don't care how many timescales astronomers set up for their special purposes,
and I encourage them to have lots of 'em, just as needed.

What I object to is tying the world's civil times to the rotation of the
Earth: civil days should always consist of 24 h of 60 m of 60 SI seconds each.

I also care, as a practical matter, that the name "UTC", which is used
in (almost all of) the world's civil time legislation, be kept for that
purpose. Astronomers can very well switch to a different abbreviation for
their |UTC - UT1| < 0.9 timescale.

What is the sound of Perl?  Is it not the       John Cowan
sound of a [Ww]all that people have stopped
banging their head against?  --Larry  
Received on Mon Jan 27 2003 - 10:54:06 PST

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