[quote] Assuming that a dial should read only local solar time is a rather limited view.
[/quote] … :-) What? … So, an expressed preference is a “limited view”? :-) … LTST stands for Local-True-Solar-Time. … A dial that reads in LTST at your latitude *at your standard meridian*…instead of *where the sundial is*, makes no sense. … It doesn’t make it any easier for viewers to obtain clock-time from the dial. That’s because, if the dial reads in your LTST, where the dial is, then, when making the correction-table, the longitude-correction-constant can just be added to every EqT entry, resulting in a combined-corrections table. … Then, the user’s task, for converting from dial-time to standard time, is exactly the same: Add a correction from a correction-table. … In other words, making dial read in LTST at your standard-meridian, instead of where the dial is, doesn’t make it any easier for the viewer to get clock-time from the dial. … But what it DOES accomplish is that it makes it necessary to apply a correction in order to get LTST (where you are) from the dial. … [quote] While it might be of interest to the dial purist [/quote] … LTST, Sundial-Time is the time-of-day that standard-time is based on & approximated. …but LTST is the real-thing. A dial that reads in LTST is telling you the actual time-of-day by the Sun. … For appointments, & catching a scheduled bus, train or flight, clock-time is what matters. For the Sun’s time-of-day, LTST is what it’s about, & what standard-time is merely a rough approximation of. … Yes, other kinds of hours have been used. Temporary Hours must have been useful if you had some task that needed daylight, &, to evaluate your progress in that task, it was helpful to know what fraction of the day has elapsed. You’ve plowed ¾ of the field, & about ¾ of the day has elapsed, & so you know that your progress is good. … Myself, I personally don’t like Temporary Hours, because I don’t want to be told what fraction of the day has elapsed, because it sounds like negative news. It seems to me that it emphasizes a negative interpretation of the time-of-day. Just my impression. … Co-Italian Hours can be very relevant, however, when it tells you how many hours of daylight remain. Better yet, I’d prefer being told how many hours remained until the end of evening Civil-Twilight. … My next sundials will give French Hours (equal 15-degree hours) & Co-Italian Hours (but hours till the end of evening Civil-Twilight instead of Sunset). … Also, my next sundials will have declination-lines for the Solar ecliptic-months (Aries-Pisces)., marked with the old symbols for those ecliptic-months. I’ll also add declination-lines for some days during the waxing half of the year, when the Solar-Declination has gone significant fractions of the way from its Winter-Solstice value to its Summer-Solstice value. …&, additionally, declination-lines for the ancient Celtic cross-quarter seasonal-holidays. … [quote] it is not particularly useful to the general population [/quote] … News-flash: People nowadays take pleasure from, & admire sundials for reasons other than practical-need. … Sundials are liked & looked-at & read because of their beauty & their natural significance, directly showing nature’s time, the Sun’s own time, based on where the Sun actually is. …not clock-time. … As I mentioned, LTST is what standard-time is based on & approximates…but LTST is the real-thing. The genuine natural Solar time-of-day…the kind expressed in equal 15-degree hours. … Clock time can indeed be important, when you have an appointment, meeting job deadline, or must catch a bus, train or plane, etc. That just isn’t part of what people like about sundials. … As I’ve mentioned, I used to use & carry a tablet-dial, when reliable accurate watches were expensive. It had a combined longitude-correction-constant + Eqt, on the top of the closed tablet. One single correction-table for the combined correction. … [quote] and often requires a lot of explanation. [/quote] … How hard is it to tell someone that the Sundial tells the time based on where the Sun is, as opposed to clock-time, which has less relation to the Sun’s time. … A Sundial that reads directly in the LTST where you are doesn’t need any correction for that. … Getting clock-time from a sundial that reads directly in the LTST at your standard-meridian needs the EqT correction to be applied, to get standard-time. …but also needs a correction to be applied to get your LTST where the dial is. … So which is really simpler?. … [quote] And it makes us seem like an eccentric clique. [/quote] … People don’t come over & look at a Sundial because they want clock-time from it. They like its beauty & its Solar nature significance, when it directly tells them the time based on where the Sun is, Sun’s time, nature’s time. … [quote] The dial produces a shadow. The hour lines and other indications are strictly our interpretation and a particular one should not be forced on everybody else [/quote] … I didn’t force anything on you. I expressed my preference, & I asked why anyone would want a dial to directly read the LTST at the standard-meridian instead of where you are, & I told why that modification doesn’t make it any easier to obtain clock-time, but does make the dial require a correction for local LTST. On Tue, Apr 4, 2023 at 7:17 PM <kool...@dickkoolish.com> wrote: > Assuming that a dial should read only local solar time is a rather limited > view. While it might be of interest to the dial purist, it is not > particularly useful to the general population and often requires a lot of > explanation. And it makes us seem like an eccentric clique. The dial > produces a shadow. The hour lines and other indications are strictly our > interpretation and a particular one should not be forced on everybody else. > --- > > > > On 2023-04-04 13:05, Michael Ossipoff wrote: > > > > On Tue, Apr 4, 2023 at 08:45 <kool...@dickkoolish.com> wrote: > > Rotating the dial plate around a vertical axis is wrong because the hours > lines are not at constant angles. > > Rotating the whole dial around the polar axis is the correct way to adjust > a local solar time dial to a different longitude, the time zone center, for > example. > > Having a dial show the time in a different location is strictly a creative > choice. > --- > > > Rotating the dial about the vertical axis & then doing the non-meridian Al > tipping, in the right combination, is how you get the result that the dial > is oriented (still in the meridianal-plane) to give Local True Solar Time > at your standard meridian. > > > I don't know why anyone would want to do that, unless it's important to > keep using an old EqT plaque. > > > > On 2023-04-04 08:44, Jack Aubert via sundial wrote: > > 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. > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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