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 1/10000 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 > >
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