Hi Lugi,
thanks for the simulation. Very interesting.
In the meantime I got quite a few advices and informations about the
trifilar sundial.Thanks again to all senders.
I must confess that I am still struggling to understand the mathematical
background behind it. Not beeing a mathematician I still hope however that
one day I will find the time to devellop a program by myself which helps to
understand the dial and the many versions it seems to work. Untill than....
Thanks again to you and all the others who helped
Siegfried
Siegfried Netzband
Hebelstr. 12
75233 Tiefenbronn
Tel: 07234 2802
Fax: 07234 942909
Mob: 0151 53083636 / 0160 1531634
E-Post: [email protected]
Skype: siegfried75233<http://www.ferienhaus-frieseneck.de>
-----Original-Nachricht-----
Betreff: The Trifilar sundial of prof. Rouxel
Datum: 2020-10-04T18:19:29+0200
Von: "Luigi Ghia" <[email protected]>
An: "[email protected]" <[email protected]>
Hi all,
a few weeks ago Mr. Siegfried Netzband has requested some explanations
about the Trifilar Sundial invented by prof. Bernard Rouxel and Fabio
Savian has sent to the Sundial list a copy of the original paper
translated in Italian and published on the "XV Seminario di Gnomonica".
So I am pleased to post to this list a link where you can find an
animation used during the presentation of the paper in order to show this
Rouxel's masterpiece at work
<https://youtu.be/5psGMuzcTyM>
The animation has be made by me with the help of Tonino Tasselli and has
been computed for the summer solstice day.
On the sundial plane the tree wires shadows, crossing each other, form a
moving triangle. The triangle becoming smaller and smaller collapses into a
point exactly at noon.
The point where the triangles collapse during the year migrates up and
down along the green lines so this line is the meridian line and may be
quoted with dates or zodiac symbols.
Anyway with a different arrangement of the tree wires (for example with a
rotation of the whole wire system about the polar axis) you can obtain the
triple crossing in a point moving along hour lines other than noon.
Best salutations
Luigi Ghia
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