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    <42B25AB9.4060007@aiub.unibe.ch>
Date: Fri, 17 Jun 2005 08:51:15 -0000 (UTC)
Subject: Re: Proposed Changes in UTC
From: "Dehant Veronique" <v.dehant@oma.be>
To: "Gerhard Beutler" <beutler@aiub.unibe.ch>,
        "Daniel Gambis" <daniel.gambis@obspm.fr>,
        "Clark Wilson" <clarkw@maestro.geo.utexas.edu>,
        "Christian Tscherning" <cct@gfy.ku.dk>
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Dear all,
After having discussed with Daniel Gambis, as the ITU WG working on that
problem has been asked to provide with official positions of the Union on
the problem, I propose to bring this up at the EC in Cairns.  Daniel
Gambis has agreed to brief us about this as he will be in Cairns. He will
also send to me material that we could further provide to the EC members.
Thank you for your consideration,
Veronique
> Dear Clark,
> I thank you very much for your e-mail. I have heard of this initiative
> and I believe that it is rather controversial. Institutions like ours
> (working in fundamental astronomy/celestial mechanics) are probably
> among those seriously affected by such decisions. Personally, I do not
> like this proposal -- despite the fact that I am very well aware of the
> inconeniences associated with leap seconds. By relaxing the limit from a
> fraction of a second to a fraction of an hour will create a "millenium
> problem" in a future generation and not something manageable for our
> (and all future)  generation(s). I am against such easy solutions from a
> philosophical point of view.
> Please do not take this as the official IAG answer, however. This is my
> personal opinion. I would like to ask Véronique Déhant, president of IAG
> Commission 3 (Earth Rotation and Geodynamics) to come up with the
> official IAG answer after consulting with this and other commissions. We
> may also discuss the issue at the Cairns IAG Executive Committee
> meeting. Would a reply by the end of September be ok?
> I did, by the way, not mention the space geodetic services, because I
> assume that they, as very directly affected bodies, have been consulted
> "autonamtically" by the IERS. Should this not have been the case, we
> would have to give them the opportunity to react through this IAG
> channel, as well. Please let me know whether this step is necessary or
> not.
> Kind regards
> Gerhard
>
>
> Clark R. Wilson wrote:
>
>> Dear Gerhard: As the IAG/IUGG representative on the International
>> Earth Rotation Service Board,  I am writing to you as IAG president.
>> The purpose is to send you documents related to proposed changes in
>> Coordinated Universal Time and the use of leap seconds, and ask
>> whether the IAG would like to provide comment on the proposal.
>> Comments can be directed to Daniel Gambis daniel.gambis@obspm.fr
>>
>> My understanding is that the proposal will be considered for adoption
>> in November 2005 by the ITU.  The purpose is to effectively do away
>> with leap seconds which are a nuisance in many timing applications.
>> After December 21 2007, the tolerated difference between UT1 and UTC
>> will be 1 hour, rather than the present 0.9 seconds, so leap seconds
>> (or leap hours or other adjustments) would not be required for
>> hundreds or thousands of years.
>>
>> Best regards,
>>
>> Clark R. Wilson
>> Chairman, Department of Geological Sciences
>> Wallace Pratt Professor of Geophysics
>> Jackson School of Geosciences
>>
>> Office location: GEO 4.220C
>>
>> Mailing Address:
>> The University of Texas at Austin
>> Geol Science Dept
>> 1 University Station C1100
>> Austin, Texas 78712-0254
>>
>> Phone   512-471-5008
>> FAX             512-471-9425
>> email           crwilson@mail.utexas.edu
>
>
>


-- 
Veronique Dehant
Royal Observatory of Belgium
3 avenue Circulaire
B 1180 Brussels
Tel: +32 2 373 0266
GSM: +32 475 57 59 53
Fax: +32 2 374 98 22