The Museo Galileo Museum is located in Palazzo Castellani, Florence, next to Piazza della Signoria and Uffizi Gallery. Visitors and local tourists pass by daily. Now You can enjoy it together with the museum’s giant sundial. Four years ago, Florence watch brand Panerai entered into a partnership with a cultural institution dedicated to protecting Galileo’s heritage, and the giant sundial was restored with the assistance of Panerai.
Panerai’s strong support not only restored the magnificent works completed in 2007 and designed by Luis e Schnabel and Filippo Camerota, but also shot the complex operation principles of the sundial into short films for display on the Galileo Museum website.
Panerai has sponsored the Galileo Museum since 2012. In the same year, it assisted the museum to create interactive content in the exhibition area entitled ‘Measurement of Galileo and Time’, allowing visitors to learn about the research and development of this great Tuscan mathematician, scientist and astronomer. The discovery laid the foundation for contemporary timepiece machinery. One of the rooms in the exhibition area exhibits the Panerai Jupiter: this exquisite and complex planetarium, centered on the earth, displays the current position and trajectory of the current sun, moon and Jupiter, and presents four orbiting Jupiters discovered by Galileo Satellite. The two parties have continued their partnership, and Panerai has promised to fund the Galileo Museum every year to support its preservation and promotion of Galileo’s outstanding heritage projects.
Galileo Museum Sundial
The sundial is an ancient time-measuring instrument, consisting of a pan and a needle on the pan, for measuring time. By changing the position of the sun over time, it looks like it is orbiting the earth regularly, and the index projection on the disk also moves with it. People only need to observe the projection to read the time.
The sundial at the Galileo Museum consists of a dial engraved on the sidewalk and two bronze pillars that symbolize day and night. A copper pillar representing the daytime faces the Arno River in the south. The pillar is engraved with a vertical meridian. The pillar is a ‘lucifer’ devil shaped like a snake and a lizard. The tail is projected on the meridian under the sun, showing the year. The midday position of each period. The copper cylinder representing the night is facing north. The cylinder is engraved with two constellations that can identify polar stars: Ursa Major and Ursa Minor. The wind rose at the bottom of the needle shows geo-location. The ground is paved with marble travertine and brass, with glass and marble constellation symbols, and extends about 15 meters from the entrance of the museum. During the winter solstice and summer solstice, the sun shadow falls on the entrance of the museum and the bottom of the needle. Dali travertine has multiple arcs running through the meridian to display the date, while brass radiation forms a grid with the arcs of the winter and summer solstice to display the hour.
The meridian is inlaid with four materials, representing different seasons and elements, including marble representing autumn and earth; glass representing winter and water; graystone (pietra grigia) symbolizing spring and wind; and bronze for summer and fire representative.
How Sundial Works
The large bronze stinger has a glass polyhedron on its tip and its projection shows the time and date. The hour markers from 9 am to 2 pm are engraved on the brass radiation. The date is displayed on the horizontal Dali travertine line, depicting the daily pace of the sun at various times of the year, and accurately showing the moment when the sun enters each star house. The slender projection of the sundial moves with the change of the day and season, indicating the true solar time, that is, the time defined according to the sun’s trajectory, which is different from the standard time displayed by the watch and clock. There is a periodic difference in real solar time, which may differ from standard time by a quarter of an hour or more.
When daylight saving time is implemented, in addition to the astronomical time difference, observers need to add one hour by themselves. For example, in February, the real needle will be projected near the 12 o’clock mark at noon, but in July, the noon will be around 13.20 daylight saving time. When observing the hours and dates, look at the hourly radiation and calendar arcs that are closest to the projection of the needle. When the sun shadow is not on the hour line, the observer can reasonably calculate half an hour and a quarter of an hour by dividing the space in the center of the two hour lines into half and half. Observers can also accurately calculate the date through the constellation symbol and the scale indicating the beginning of the month on the meridian line.