[LEAPSECS] A leap second proposal to consider -- LSEM
Tom Van Baak
tvb at LeapSecond.com
Thu Nov 4 17:36:28 EDT 2010
> All forms of UT1 have been direct measures of earth rotation. One can
> argue about zero points and drifts, but the underlying purpose of UT1
> is to monitor rotation with a value that tracks where the sun is over
> the earth. In that sense UT1 tries to be a form of mean solar time,
> so it merits a name consistent with the 1884 IMC "universal day" and
> the 1928 IAU "universal time".
Back when the understanding of the "universe" consisted little
more than our solar system, and back before quartz or atomic
clocks, this made sense. Now maybe it should be renamed ST
for solar time, rather than UT for universal time.
> This is not the case with a purely atomic time scale uncorrected for
> the rotation of earth. To name that "universal time" is abuse.
Since there are quite a few more cesium atoms than there are
planet earth's one could argue that atomic time scales are more
"universal" than an earth/sun rotation/revolution-based scale, no?
More information about the LEAPSECS