Re: Most accurate Sundial in the World
On 13/04/2014 20:24, Brooke Clarke wrote: Hi Dan: Don't know the answer to your question but have a comment. The dial itself doesn't appear to have a built in correction for the EOT, i.e. the correction comes from the adjacent instruction bulletin board. This allows changing the instructions to account for year to year variations like leap year or leap seconds. If that's the case then I don't think it's fair to say the dial is that accurate, you could say the dial plus the correction table is that accurate. Dials like the Schmoyer or direct reading equatorial have the EOT and longitude corrections built in. http://www.prc68.com/I/Sundial.shtml#Schmoyer Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html You might just as well say that the Sun itself isn't that accurate, because you need a correction table to convert solar time to clock time. -- -- Richard Mallett Eaton Bray, Dunstable South Beds. UK --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Most accurate Sundial in the World
Hi Dan: Don't know the answer to your question but have a comment. The dial itself doesn't appear to have a built in correction for the EOT, i.e. the correction comes from the adjacent instruction bulletin board. This allows changing the instructions to account for year to year variations like leap year or leap seconds. If that's the case then I don't think it's fair to say the dial is that accurate, you could say the dial plus the correction table is that accurate. Dials like the Schmoyer or direct reading equatorial have the EOT and longitude corrections built in. http://www.prc68.com/I/Sundial.shtml#Schmoyer Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html cerculdestele . wrote: Does anyone know if this record has been broken? http://www.engadin.stmoritz.ch/sommer/en/activities/mountain-adventure/mountains/muottas-muragl-mountain-adventures/sundial-muottas-muragl/ Dan Uza Romania --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Most accurate Sundial in the World
That is pretty bold claim, one which I do not make with my own dials. This dial is designed to be readable to 5 seconds, but accuracy could be another matter. There are so many variables that affect accuracy, and some are easily overlooked. Specifically, critical alignment with the north celestial pole is extremely hard to achieve. A magnificently designed dial can perform only as well as its installation will allow. Accuracy related to alignment varies with time of day and the sun's declination; I have not done the math for a while, but I think even a misalignment by 1/10th of a degree an any direction will preclude accuracy of say, 15 seconds for a least part of the day, during some part of the year. Year-on-year variation in the EoT is another matter, but could be properly compensated if accounted for. Claims of accuracy (for civil time) can be evaluated only by simultaneous measurements of dial and clock at different times of day, and different times of the year. Even a broken watch is accurate twice a day. -Bill On Sun, Apr 13, 2014 at 9:54 AM, cerculdestele . wrote: > Does anyone know if this record has been broken? > > > http://www.engadin.stmoritz.ch/sommer/en/activities/mountain-adventure/mountains/muottas-muragl-mountain-adventures/sundial-muottas-muragl/ > > Dan Uza > Romania > > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Most accurate Sundial in the World
Does anyone know if this record has been broken? http://www.engadin.stmoritz.ch/sommer/en/activities/mountain-adventure/mountains/muottas-muragl-mountain-adventures/sundial-muottas-muragl/ Dan Uza Romania --- https://lists.uni-koeln.de/mailman/listinfo/sundial
