Nocturnal dials are star clocks to tell time by the stars. This instrument replicates an original nocturnal dial created by Girolano della Volpaia in Florence in 1569, held in the Museo Galileo in Florence. It consists of three superimposed brass disks: an outermost disk of days, divided in 360 degrees, with months and zodiac signs; a middle disk divided into 24 hours with an indicator for “Media Nox”; and a top disk with 24 numbered teeth.
Exhibit Gallery OERs
Coma Berenices is the only one of the modern 88 official constellations named after a historical figure. It represents the hair of Berenice, Queen of Egypt (267 221 BCE), who reigned with Ptolemy III Euergetes. Learn more about this in this learning leaflet.
Vincenzo Galilei was among the first music theorists to advocate for a new system of tuning based on performance, instead of the mathematical principles of music set fourth by Pythagoras. Pythagorean music theory bases pitch on the mathematical proportions of dividing a string. Vincenzo's primary problem with this system is that, although it is great for the mathematician and the music theorist, it is impractical for the performer. All music based on this particular system of tuning would inevitably sound out of tune and unpleasant. In this learning leaflet learn about the tuning systems in the late-Renaissance period.
Can you identify the five regular solids?
Throughout history the regular solids were studied with keen interest by astronomers, mathematicians, artists, architects and philosophers. The Pythagoreans proved that there are only five regular solids: the cube, triangle, octahedron, dodecahedron, and icosahedron.
Is there a mathematical basis of the universe?
Johann Kepler's "Mystery of the Universe" is one of the brilliant illustrations in the history of astronomy. Kepler used the five regular Pythagorean solids to refute the major objections to Copernicanism. In this work he demonstrated that vast empty regions lying between the planetary spheres, which were required by Copernicus, were not wasted space. Rather, these gaps perfectly matched, within the limits of observational error, the geometry of the 5 regular Pythagorean solids.
Can you identify simple musical intervals?
The ancient Pythagoreans envisioned the heavens as a musical scale, comprised of celestial spheres rotating according to harmonious music. For Robert Fludd, a seventeenth-century physician, the universe was a monochord, its physical structure unintelligible without an understanding of music. In this activity, explore the relationship between mathematics, astronomy, and music.