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 [EMAIL PROTECTED] 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