On Thu, Jun 22, 2017 at 12:31, Donald L Snyder <dsny...@wustl.edu> wrote:
> Since > atan(1.61803) equals 58.28 degrees, a horizontal sundial in a city at > this latitude could have a triangular gnomon with a height to base > ratio that is golden. > Don Snyder > > On 6/21/2017 10:00 PM, Michael Ossipoff wrote: > > > > On Wed, Jun 21, 2017 at 5:27 PM, Brooke Clarke <bro...@pacific.net> wrote: > >> Hi Roderick: >> >> I also have a book on this number that makes the case that there is no >> such ratio. >> > > > Your book is mistaken. > > If A/B = (A+B)/A, then A/B is the golden ratio. > > If a line-segment is divided into two parts related by that ratio, then > the golden ratio is also called the golden section. > > If the interval between two numbers is divided into two intervals related > by the golden ratio, then the golden ratio is also called the golden mean. > > > >> For example if you look at a photograph of something where do you put the >> markers to make the measurement? >> > > Along two mutually-perpendicular edges, measured from a common corner? :^) > > > Michael Ossipoff > > > >> Brooke >> Clarkehttp://www.PRC68.comhttp://www.end2partygovernment.com/2012Issues.html >> >> -------- Original Message -------- >> >> Hi all, >> >> I have been reading a book on the Golden Ratio which is 1.6180339887. It >> describes how the Golden Ratio describes how the spiral of a sea shell is >> produced. And how nature uses the Golden Ratio on the size of leaves etc. >> >> Does anyone know if sundials have ever been produced useing the Golden >> Ratio. The Golden Ratio goes back in history so one wonders if it was ever >> applied to sundials. >> >> The book describes that the short and long sizes of credit cards are >> close to being the Golden Ratio. >> >> LongSide/ShortSide = Golden Ratio. >> >> Regards, >> >> Roderick Wall. >> >> >> >> ---------------------------------------------------https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> >> --------------------------------------------------- >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> > > > ---------------------------------------------------https://lists.uni-koeln.de/mailman/listinfo/sundial > > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > -- Cell +1 778 837 5771
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