On Fri 2006-12-29T07:43:56 +0000, Tony Finch hath writ:
> Astronomers still count Julian
> years (365.25 days instead of exact years) when dealing with long MJD
> intervals.
Such intervals are almost always expressed in the IAU's time scale of
Terrestrial Time (TT) which is taken to be a more uniform measure than
any practically available time scale, including TAI. As such it is a
simplification for the sake of human cognition that comes close to the
notion of year without any intent to match observable or political
reality.
--
Steve Allen <sla_at_ucolick.org> WGS-84 (GPS)
UCO/Lick Observatory Natural Sciences II, Room 165 Lat +36.99858
University of California Voice: +1 831 459 3046 Lng -122.06014
Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m
Received on Fri Dec 29 2006 - 00:06:43 PST