[LEAPSECS] Solar time: From mean solar days, to mean solar years

[Preben Nørager]

Thank you Keith, my stupid mistake.
Den 20/08/2014 16.44 skrev "Keith Winstein" <keithw at mit.edu>:

> 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 <samp5087 at gmail.com>
> 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
> > LEAPSECS at leapsecond.com
> > http://six.pairlist.net/mailman/listinfo/leapsecs
> >
> _______________________________________________
> LEAPSECS mailing list
> LEAPSECS at leapsecond.com
> http://six.pairlist.net/mailman/listinfo/leapsecs
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://six.pairlist.net/pipermail/leapsecs/attachments/20140820/9252e27a/attachment.html>