Egnazio Danti (1536-1586 Mathematiker & Kartograph) -The equinox sphere (Armillarsphäre)
placed on the facade of the Basilica of Santa Maria Novella (replica) 3 Löcher, 2 in
Marmorfassade agieren als camera obscura (solstizio invernale Capricorn + equinozio , 1 Loch in
Glasrosette (Meridianlinie); Sonnenlicht am Boden der Basilica
Located on the south facade of Santa Maria Novella, Florence, this armillary sphere was
designed and erected by Ignazio Danti in 1572 enabling him, with other instruments, to
measure the exact length of the year by determining the true equinox. At the vernal equinox in
March 1574 Danti observed that it was eleven days early according to the Julian calendar. This
was one of the factors that led to the introduction of the Gregorian calendar in 1584
https://www.smn.it/en/events/autumn-equinox-in-santa-maria-novella/
Auch von G.D. Cassini in der Basilica San Petronio in Bologna
Danti-Armillar-Novella-info
Ignazio Danti: entdeckte 1574 die 11-Tage-Lücke zwischen dem julianischen Kalender und
dem Sonnenjahr. Daraufhin wurde er ein wichtiger Fürsprecher der gregorianischen
Kalenderreform.
Als leitender Kosmograf (primario cosmografo) sowie Lehrer des Grossherzogs der Toskana
(maestro e cosmografo del Serenissimo Gran Duca di Toscana) hatte Danti schliesslich ab Juli
1571 das Privileg, in unmittelbarer Nähe des Grossherzogs, im Palazzo Pitti, zu wohnen.
http://michel.lalos.free.fr/cadrans_solaires/autres_pays/italie/toscane/florence/doc_cadran
s/florence_s_m_novella_meridienne.pdf
Christophorus Clavius: Die Gregorianische Kalenderreform wurde im Wesentlichen von ihm
auf Basis der Vorschläge des 1576 verstorbenen Aloisius Lilius gestaltet und durchgeführt.
Aloisius Lilius: machte in einem heute verschollenen Manuskript einen Vorschlag für die
Kalenderreform, den sein Bruder Antonio, der Leibarzt des Papstes war, den Experten des
Papstes Gregor XIII. 1575 präsentierte, zu denen u. a. die Mathematiker und
Astronomen Christophorus Clavius,Pedro Chacón (1526–1581), Ignazio Danti und der
Kardinal Guglielmo Sirleto gehörten. Lilius starb bald darauf 1576.
With this armillary sphere, Danti made
accurate measurements of the exact length
of the year. Along with principal astronomer
Clavius, Danti was commissioned by Pope
Gregory XIII to correct the calendar (Julian),
and produced the Gregorian Calendar in
1582, subtracting ten 'leap back' days in the
process. The Julian Calendar was based on
a year of 365.25 days. The number decided
upon by the astronomers of the late 16th
century was 365.2422 days. February 29th
leap days were henceforth omitted if they are
divisible by 100, but re-instated if they were
divisible by 400. For example in 2000, we
had a leap year, but they didn't in 1900. This
picture was taken on September 19th, so the
'horizontal' shadow is nearly exactly
horizontal, as it will be at the equinox.
http://www.nfo.edu/family/italy/meridiana.html
Here is the scientist’s beam of light that travels
down to the Meridian four ??? times a year. Sta
Maria Angeli Rom
Loch!
2 Löcher in West??????-Fassade
Il foro gnomonico
Il momento di massima coincidenza con il punto
dell'Equinozio (Foto Claudio Mastrodicasa)
Un disco di luce proiettato dal foro gnomico sta per raggiungere il
punto indicato per l'Equinozio (Foto Maurizio Rufino) Un fascio di luce attraversa il foro gnomico nella
facciata (Foto Giovanni Casini)
Una folla di persone si riunisce attorno alla meridiana
(coperta ancora da un telo) per assistere all'evento
Einweihung des Meridian 22 Sept. 2016
https://www.smn.it/it/magazine/inaugurazione-delle-meridiane-di-santa-maria-novella/
