To be a pedant [but if you can't be one on the leapsecs mailing list...], the SI second is *9192631770* periods of the radiation etc. Your figure is high by 1000.
On Wed, Aug 20, 2014 at 9:22 AM, Preben Nørager <[email protected]> wrote: > > In the discussion about whether or not to drop the leap second, I think it > is not a question about solar time or not solar time. It is in other words > not a question about either solar time or atomic time. > > > > If we drop the leap second it will be in favour of another timescale, which > uses only atomic clocks to tell the time, but the time in that other > timescale will still be based upon a kind of solar time. > > > > About a hundred years ago it was decided, that the mean solar year, and not > the mean solar day, should be the unit of international time. > > > > In 1960 the second was defined as 1/31556925,9747 of the mean solar year, > and in 1967 the second was redefined [equally in length to the previously > defined second] as the duration of 9192632770 periods of radiation. > > > > When the second was defined in 1960 it was defined as a fraction of the > so-called tropical year. That was a mistake of wording. The tropical year is > a measurement of the solar longitude on the ecliptic, but the international > definition of the second is not based upon measurement of the solar > longitude on the ecliptic. > > > > The definition of the second is based upon Newcomb's theory of the solar > system, and in that theory it is the barycenter of the solar system, and not > the center of the sun, which defines the length of the solar year. > > > > The length of the solar year, according to Newcomb’s theory, is the time for > the longitude of the barycenter of the solar system to increase 360 decrees. > > > > The solar year, thus defined, can be measured either for one year, or for an > average of years. > > > But the 1960 and the 1967 definition of the second can also be used as an > international definition of the mean solar year. > > > > I think we should drop the leap second, and continue UTC without leap > seconds as TI [International Time], so that 1 mean solar year is the > duration of 290091231835491000 [31556925,9747x9192632770] periods of > radiation in the caesium atom. > > _______________________________________________ > LEAPSECS mailing list > [email protected] > http://six.pairlist.net/mailman/listinfo/leapsecs > _______________________________________________ LEAPSECS mailing list [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
