[LEAPSECS] A leap second proposal to consider -- LSEM

Steve Allen sla at ucolick.org
Wed Nov 3 19:31:59 EDT 2010

On Wed 2010-11-03T23:06:03 +0000, Michael Deckers hath writ:

> Since 2003, UT1 has no connection with the Sun

Actually, since 1984, see the discussion in Aoki et al.

In that discussion note that not even Newcomb's expression was
connected with the sun because he knew that his precession value was
wrong. In the archives related this subject are also the longstanding
issues of the value of the constant of aberration and the problems of
the "conventional longitides". But it was Newcomb's expression which
was adopted by international agreement as the formula for computing
mean solar time in order that everyone could agree on its value.

If an expression is deficient it can be amended, but that only works
if there is agreement on what it is trying to do.
I see the point of "mean solar time" not as "how accurately does the
expression represent the sun over the earth?" but as "does the
expression even try to represent the sun over the earth?".
I think that the discussions and intentions surrounding the current
draft revision of TF.460 indicate that it does not try.

Steve Allen <sla at ucolick.org> WGS-84 (GPS)
UCO/Lick Observatory Natural Sciences II, Room 165 Lat +36.99855
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Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m

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