[quote] Yes i's an image of the Sun, if the ratio of hole-to-spot distance to hole-diameter isn't much less than the ratio of the Sun's distance to its diameter. [/quote]
Alright, it isn't a very *accurate* image unless the ratio of hole-to-spot distance to hole-diameter is considerably greater than the ratio of the Sun's distance to its diameter. Michael Ossipoff 2019, Week 12, Thursday 1632 UTC On Wed, Mar 13, 2019 at 6:32 PM Kurt Niel <[email protected]> wrote: > In German language we have: > > WOZ Wahre Ortszeit (= LAT, 12:00 = sun is exactly south at the location) > > MOZ Mittlere Ortszeit - within a year the medium length of a day`s time > WOZ = MOZ + EoT > > MEZ Mitteleuropäische Zeit = MOZ at longitude 15° East > > MESZ Mitteleuropäische Sommerzeit = MEZ + 1 h > > Regarding the ongoing diskussion whitch time shall we take in the future > if we leave the yearly double change standard/summer/daylight saving time: > I would prefer a revolution and take only two definitions worldwide: > 1) UTC (universal time for global synchronisation) > 2) LAT (the most natural local time caused by the sun's position only). > > The calculation in between should not be a problem by GPS driven > watches/smartphones/IoT-devices. Even mechanic watches would be able to do > the job for EoT - EoL can be set manually if necessary while travelling. > > Kurt > > Kurt Niel <[email protected]> schrieb am Mi., 13. März 2019, 22:51: > >> Dear sundialists, >> >> within my sundial-/webcamproject https://kepleruhr.at/en/live-view I >> already declared the following relationship: >> >> UTC + >> EoT (equation of time) + >> EoL (equation of longitude) = >> LAT (local apparent time) = >> WOZ (Wahre Ortszeit) [German] >> >> Kurt >> >> Dan-George Uza <[email protected]> schrieb am Mi., 13. März 2019, >> 22:21: >> >>> Perhaps "equation of longitude"? >>> >>> Dan Uza >>> >>> On Wed, Mar 13, 2019, 20:50 Julian Lush <[email protected]> >>> wrote: >>> >>>> How about longitude adjustment? >>>> >>>> Julian Lush >>>> 72 Bromfelde Road, London SW4 6PR >>>> 020 7622 9497 07815 637706 >>>> ------------------------------ >>>> *From:* sundial <[email protected]> on behalf of Frank King >>>> <[email protected]> >>>> *Sent:* 13 March 2019 12:29 >>>> *To:* Dan-George Uza >>>> *Cc:* Sundial List >>>> *Subject:* Re: dischrony >>>> >>>> Dear All, >>>> >>>> I have a mild distaste for "correction" since >>>> it implies something is wrong. In particular >>>> 'local mean time' and 'local mean time-zone time' >>>> are both correct, but different, times. One is >>>> offset from the other but this offset is in no >>>> sense a correction! >>>> >>>> To me "offset" is neutral. >>>> >>>> There are, of course, many many different >>>> times in current use. Here are just a few: >>>> >>>> TAI, UTC, UT1, UT2, GMT, GST, GPS time >>>> >>>> None of these is wrong but each is offset >>>> from all the others. >>>> >>>> Sometimes the offset is constant such as >>>> the difference between TAI and GPS time >>>> >>>> Sometimes the offset changes infrequently, >>>> such as the difference between TAI and UTC >>>> (which changes only when there is a leap >>>> second). >>>> >>>> Sometimes the offset changes continuously, >>>> such as the difference between GST (sidereal >>>> time) and GMT. >>>> >>>> This suggests that the word 'constant' is >>>> not generally appropriate and is why I am >>>> not keen on the Italian "costante locale". >>>> >>>> This is actually a false assertion when >>>> referring to local mean time versus local >>>> time-zone time because in most places the >>>> reference time zone is shifted 15 degrees >>>> backwards and forwards at the whim of >>>> legislators! The offset is not constant! >>>> >>>> Dan-George asks: >>>> >>>> how would you translate the Italian >>>> "foro gnomonico" >>>> >>>> In English, this translates literally as >>>> "gnomonic hole" but this would be a bad >>>> translation! It generally refers to the >>>> hole in the roof (or possibly a side wall) >>>> of a cathedral or large church that lets >>>> in the sun so as to cast an image of the >>>> sun on the floor. >>>> >>>> The best English equivalent is "aperture >>>> nodus" but that isn't quite the same thing. >>>> An aperture nodus provides a spot of light >>>> on the dial plate, not an image of the sun. >>>> >>>> The French "oeilleton" is more challenging! >>>> In English, this translates literally as >>>> "eye-cap" which I think of as something >>>> for medical use, for washing your eyes. >>>> >>>> I rather suspect that the French also use >>>> this to mean aperture nodus but I should >>>> like confirmation. >>>> >>>> Frank >>>> >>>> Frank King >>>> Cambridge, U.K. >>>> >>>> --------------------------------------------------- >>>> https://lists.uni-koeln.de/mailman/listinfo/sundial >>>> >>>> --------------------------------------------------- >>> https://lists.uni-koeln.de/mailman/listinfo/sundial >>> >>> --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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