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

[Michael Deckers]

    On 2010-11-03 18:43, Poul-Henning Kamp observed on
    a remark by Rob Seaman:


>  >  "Universal Time" *means* "mean solar time".

>

>  It probably did in the 1800's, in these days of Lego-toys on Mars,

>  most people I have talked to, find it utterly strange that a timescale

>  with "universal" in it, depends on one particular lump of rotating rock.


    Since 2003, UT1 has no connection with the Sun -- it measures
    Earth rotation independent of the revolution of the Earth around
    the Sun (except for geodesic precession, sigh). So "mean solar
    time" may well be considered a misnomer for UT1.

    Since sidereal time is still well-defined (based on both UT1 and
    TT), any definition of a mean sun could resurrect mean solar time
    in the original sense, if desired. For the time being, it would not
    deviate appreciably from UT1 (because that's how UT1 was redefined).

    Michael Deckers.