On Fri 2004-01-30T17:41:03 -0500, Seeds, Glen hath writ:
> My concern is for the general populace, not for astronomers. For the former,
> "apparent" is what matters, and in matters in lay terms, not in astronomical
> terms.
The papers that define the constants which are now being used to
calculate UT1 explicitly assert that their expressions are only
expected to be valid for about 100 years.
The rules for UTC imply that being able to agree on a
conventional/civil mean solar time which is within a second of the
"true mean solar time" is sufficient.
Even in 100 years a replacement expression designed to continue to
ignore the sun and simply give continuity with the current form of UT1
will be well within one second of anything that might satisfy the
definition of the "true mean solar time".
We have many centuries before we need to take action about defining
such a "true mean solar" quantity which might replace UT1 for the
purposes of determining leap seconds in UTC.
Since the current expressions for UT1 indicate that we must
revisit the notion of UT1 within a century, there is no need
to worry about dismaying the general populace on this issue.
Hopefully the nomenclature working group will have long since
clarified conundrums like the one posed in the title of this paper
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2001AJ....122..482F
to wit
"Global Rotation of the Nonrotating Origin"
--
Steve Allen UCO/Lick Observatory Santa Cruz, CA 95064
sla_at_ucolick.org Voice: +1 831 459 3046 http://www.ucolick.org/~sla
PGP: 1024/E46978C5 F6 78 D1 10 62 94 8F 2E 49 89 0E FE 26 B4 14 93
Received on Fri Jan 30 2004 - 15:00:54 PST