Re: [LEAPSECS] Precise time over time

From: Poul-Henning Kamp <>
Date: Thu, 11 Aug 2005 09:46:18 +0200

In message <>, Rob Seaman writes:

>The method you suggest would work, but I believe mean and apparent
>solar time historically were derived from nighttime sidereal

In Denmark the last "holder" of the job was the "Carlsberg Meridian
Telescope" which has subsequently been moved to La Palma:

It was one of the first telescopes to be equipped with a computer
so it could carry out an observation schedule autonomously.

(I have been told, but am not quite sure I belive, that this was
where it was first documented that the thermal disturbances caused
by humans in the dome degraded observation performance.)

>I suspect even folks
>on the extreme opposite sides of the leap second question would today
>prefer a single world wide civil time standard.

Yes, anything else would just be asking for trouble. The problem
is that today we have two:
        Correct implementations of UTC
        Botched implementations of UTC

The USA proposal is not about scientific correctness as much as
about the economic implications of living with or fixing the second
category, compared to redefining UTC so the two become identical.

As I understood the situation last week, nobody in the gang here
had problems with leap seconds if we got a longer warning (40-50

So what prevents us from writing up our own proposal to ITU ?

I'm pretty sure that we could get a rather impressive list of
signatures from both camps if we did a bit of lobby work in our
respective communities.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk_at_FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Received on Thu Aug 11 2005 - 00:46:34 PDT

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