Re: No more leap seconds!
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 > > -
Re: No more leap seconds!
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 Savian fabio.sav...@nonvedolora.it www.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
RE: No more leap seconds!
Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die eigentliche Nachricht steht dadurch in einem Anhang. This message was wrapped to be DMARC compliant. The actual message text is therefore in an attachment.--- Begin Message --- Didn't we have the same problem with the year, some centuries ago? Is it what it is. The earth is slower than our atomic clock, and so at some point, you will have to adjust - if you want noon to fall anywhere near noon, that is. Now people will complain about a leap second every few years (too often!), likewise, they will complain about a leap minute very century (too big!). If something is a fact of nature, people will complain about it and demand it go away. It won't, so they complain more, and louder. It won't help, but that only makes them be more right - everyone happy. For my part, I don't care if they wait until it's a full year they must adjust. I will just be amused by the hullaballoo that will cause when the time comes - if I live to see it; it's a fairly big adjustment. Rudolf 52-30N 4-40E --- End Message --- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: No more leap seconds!
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
Re: No more leap seconds!
Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die eigentliche Nachricht steht dadurch in einem Anhang. This message was wrapped to be DMARC compliant. The actual message text is therefore in an attachment.--- Begin Message --- It’s hard to conclude that ‘“nothing will change” for the public’, when there’s a proposal for ‘a “kind of smear”, in which the last minute of the day takes two minutes.’ > Date: Sun, 20 Nov 2022 19:56:23 -0800 > From: Steve Lelievre > To: Sundial List > Subject: No more leap seconds! > > Apparently the Powers That Be have officially decided that Clock Time is > right and Solar Time is wrong. > > Or to put it another way, the International Bureau of Weights and > Measures has voted to stop using Leap Seconds by by 2035. > > However, an IBWM representative said "the connection between UTC and the > rotation of the Earth is not lost [...] Nothing will change [for the public]" > which apparently means we'll have less frequent adjustments instead (leap > minutes?). > > https://phys.org/news/2022-11-global-timekeepers-vote-scrap.html > > Steve > > -- > Date: Mon, 21 Nov 2022 18:59:44 +1100 > From: John Pickard > > Good evening, > > I doubt it will affect dials very much, especially the EoT, ... > > https://www.theguardian.com/world/2022/nov/18/do-not-adjust-your-clock-scientists-call-time-on-the-leap-second > > -- > Cheers, John. > > Dr John Pickard. --- End Message --- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: No more leap seconds!
Sorry Steve, I sent my post before seeing yours. -- Cheers, John. Dr John Pickard. On 21-November-2022 14:56, Steve Lelievre wrote: Apparently the Powers That Be have officially decided that Clock Time is right and Solar Time is wrong. Or to put it another way, the International Bureau of Weights and Measures has voted to stop using Leap Seconds by by 2035. However, an IBWM representative said "the connection between UTC and the rotation of the Earth is not lost [...] Nothing will change [for the public]" which apparently means we'll have less frequent adjustments instead (leap minutes?). https://phys.org/news/2022-11-global-timekeepers-vote-scrap.html Steve --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
No more leap seconds!
Apparently the Powers That Be have officially decided that Clock Time is right and Solar Time is wrong. Or to put it another way, the International Bureau of Weights and Measures has voted to stop using Leap Seconds by by 2035. However, an IBWM representative said "the connection between UTC and the rotation of the Earth is not lost [...] Nothing will change [for the public]" which apparently means we'll have less frequent adjustments instead (leap minutes?). https://phys.org/news/2022-11-global-timekeepers-vote-scrap.html Steve --- https://lists.uni-koeln.de/mailman/listinfo/sundial
