Re: [LEAPSECS] the legacy of ephemeris time

From: Steve Allen <>
Date: Mon, 22 Dec 2003 10:50:14 -0800

On Mon 2003-12-22T10:12:27 -0500, hath writ:
> It's not about understanding the difference between earth rotation
> and time. It's whether civil time shall be tied to one or the other or
> to a compromise between them.

The ITU recognizes that it has no direct control over local civil
time, although it clearly has indirect control by means of the radio
broadcasts. That's why it is strange to see the summary slide from
Ron Beard's presentation at the most recent CGSIC meeting

The second to the last bullet reads
        Civil timekeeping is assumed as continuing with approximately
        0.1 s accuracy linked to the length of the Solar Day

This raises all sorts of hopes, questions, and maybe flames.

How exactly will civil agencies continue to keep mean solar time if
UTC vanishes? Will they have to invent a new time scale on new
broadcast channels -- or keep using the old channels?

The current ITU SRG was formed after the CCTF wrote letters regarding
leap seconds and concerns over "proliferation of timescales". Is
Beard offering a slap in the face at the CCTF for writing the letter
that got him into the chairmanship of the SRG?

Will anyone take the reponsibility of reviving the UTC standard
given that pronouncing leap second in the absence of an international
agreement might lead to liability issues if arbitrage occurs?

If a local civil agency decides that mean solar time is more
desirable, and keeps its broadcasts on something approximating UTC,
has not the ITU conceded its authority entirely?

There is a letter to the New Scientist from Petit at BIPM
and the last paragraph seems almost damning.

Has this leap seconds process come to the point where, just like 30
years ago, the gloves are being taken off during ongoing discourse?

In the case of the IAU GA 33 years ago it is clear who were the
duelists and who were the seconds counseling restraint.
In this case is there anyone with a brilliant technical solution and
the charisma to promote it, or will this entire episode result in

Steve Allen          UCO/Lick Observatory       Santa Cruz, CA 95064      Voice: +1 831 459 3046
PGP: 1024/E46978C5   F6 78 D1 10 62 94 8F 2E    49 89 0E FE 26 B4 14 93
Received on Mon Dec 22 2003 - 10:50:28 PST

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