I'd rather keep the leap-second. The fluctuation that it brings to
clock-time only has a 1-second peak-to-peak amplitude. That's completely
insignificant to dialists. & also entirely insignificant for such
things as Sunrise, Sunset, Civil-Twilight & Nautical Twilight, where a
cloud or a little mist can change the illumination a lot more than a few
seconds of time.
If they switch to leap-minutes, then we'll have to deal with a 3rd
non-negligible component to the difference between clock-time & True-Solar
Time. Now it's the longitude-correction & the EqT. But when they switch
from leap-seconds to leap-minute, there'll be a 3rd non-negligible
component: The component resulting from the long-accumulated drift or the
abrupt 1-minute correction.
Though of course the leap-second deals with variations in the
day-length,I've heard (but not verified) that actually most of what the
leap-seconds are doing is correcting for the fact that our average
day-length differs from what it was in the early 19th century, when it was
the basis of the official precise-timekeeping second.
Since that day, our diurnal-astronomical second (1/86,400 of a mean-solar
day) has changed enough that the leap-second is needed to compensate for
the amount by which the diurnal-astronomical second has changed since the
timekeeping-second standard was set in the early 19th century.
The scientists might have very good reasons why leap-minutes would work
better for them. But not for dialists or people interested in the time of
Sunrise, Sunset, Civil-Twilight & Nautical-Twilight.
On Thu, Nov 24, 2022 at 4:54 AM fabio.sav...@nonvedolora.it <
fabio.sav...@nonvedolora.it> wrote:
> Dear all, I have never commented on this topic, I do it now with a
> proposal.
>
> - The leap second takes into account a sort of 'noise', unpredictable
> before, for small variations in the speed of the Earth's rotation.
> Anyway, over the millennia this speed will decrease, so the leap second is
> not enough but the 'physical' second will deviate from the 'astronomical'
> one.
> The physical one is necessary to measure the astronomical one and they are
> two different things despite the attempts of recent centuries to make them
> equivalent
>
> - Martian days have a different second, residents will use the physical
> second as unit of measurement for their scientific instrument but they will
> want to live a 24-hour day (in any case full hours) with an astronomical
> second significantly different from the physical one.
>
> - At the end of the 18th century the meter was calibrated as 1/1 of
> the distance between the equator and the pole, it was later found that the
> measurement is a few kilometers more and also changes from one meridian to
> another, not to mention the equator.
> This did not change the unit of measurement and did not impose a wrong
> measurement of the Earth. It is accepted that the meter has an autonomous
> definition distinct from the geographic measurements of the planet.
>
> In my opinion the problem is in the name: the 'second' is a name that
> derives from a fraction of the day while the physical second is a unit of
> measurement that is still unnamed.
> If the physical second had a definition, it would help put an end once and
> for all between the demands of scientific measurement and the rhythm of a
> planet's days.
> The gnomonists are the most focused community on the history of time for
> which I am launching a proposal:
> help the scientific world to find a definition for the physical second,
> giving it a separate identity from the local astronomical second (Earth,
> Mars, etc.).
> This forum could be the place to put forward some shared proposal and
> start using it.
> It does not matter if the scientific community wants to change it, it
> would still be a success to have established that the physical second has a
> different name and identity from our dear old terrestrial second. That of
> clocks and sundials, and of our terrestrial life.
>
> Long live the second, ciao Fabio
>
>
> Il 21/11/2022 17:39, Steve Lelievre ha scritto:
>
>
> Ah, the joys of Listservs and email software. My participation sometimes
> gets of of step too: occasionally, original posts reach me after other
> people's replies.
>
> Perhaps it wouldn't be a problem if all the world's computers were exactly
> synchronized... perhaps they could use atomic clocks for that ;-)
>
> Cheers,
>
> Steve
>
>
> On 2022-11-21 12:04 a.m., John Pickard wrote:
>
> Sorry Steve,
>
> I sent my post before seeing yours.
>
> --
> Cheers, John.
>
> Dr John Pickard.
>
>
>
> ---https://lists.uni-koeln.de/mailman/listinfo/sundial
>
> --
> Fabio savianfabio.sav...@nonvedolora.itwww.nonvedolora.eu
> Paderno Dugnano, Milano, Italy
> 45° 34' 9'' N, 9° 9' 54'' E, UTC +1 (DST +2)
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
