Pulpito, lampadario e cupola all'interno della cattedrale di Santa Maria Assunta (Opera Primaziale Pisana)
Cathedral of Santa Maria Assunta, piazza del Duomo
Cattedrale di Santa Maria Assunta (Opera Primaziale pisana)Galileo Galilei's lamp: 'with the sagacity of his ingenuity he invented that very simple and regulated measure of time by means of the pendulum, not previously perceived by anyone else, taking the opportunity to observe it from the motion of a lamp, when one day he was in the Cathedral of Pisa; and making very exact experiences of it, he ascertained the equality of its vibrations' (Vincenzo Viviani. Historical Account, 1654). At the centre of the nave hangs the bronze chandelier by Vincenzo Possanti, a work that replaced the original lamp (now in Campo Santo) that Galileo Galilei observed in the Cathedral in 1581 (when he was only 17 years old). His reflections led him to formulate the theory known as isochronism of the pendulum, according to which the oscillation time of pendulums of equal length is constant, whatever the amplitude of the oscillation. In reality this theory is valid only if the oscillations are of small amplitude, but it was still the basis for the studies to come.
