Introduction to the Leaning Tower of Pisa

The Leaning Tower of Pisa (Italian: Torre pendente di Pisa or Torre di Pisa, English: Leaning Tower of Pisa) was built in August 1173. It is an independent bell tower of the Cathedral of Pisa, Italy. In the Piazza dei Miracoli in the north of Pisa, Tuscany.

There are a group of religious buildings scattered on the large lawn of the Piazza dei Miracoli. They are the cathedral (built from 1063 to the 13th century), the baptistery (built from 1153 to the 14th century), the bell tower (that is, Pisa Leaning Tower) and Cemetery (built in 1174), their outer walls are all made of milky white marble, each is relatively independent but forms a unified Romanesque architectural style. The Leaning Tower of Pisa is located behind Pisa Cathedral. ?

The Leaning Tower of Pisa is 58.36 meters high from the foundation to the top of the tower and 55 meters high from the ground to the top of the tower. The width of the bell tower wall is 4.09 meters on the ground and 2.48 meters wide at the top of the tower. The total weight About 14,453 tons, the center of gravity is 22.6 meters above the foundation. The circular foundation area is 285 square meters, and the average pressure on the ground is 497 kPa. The tilt angle is 3.99 degrees, 2.5 meters away from the outer edge of the foundation, and the top floor protrudes 4.5 meters. Tilt was first discovered in 1174.

Architectural style:

The Leaning Tower of Pisa is undoubtedly an important building in the history of architecture. Its bold circular architectural design demonstrated its originality before it tilted severely.

While designs with circular foundations were not uncommon in earlier Italian bell towers, and similar examples can be found in Ravenna, Tuscany and Umbria, Pisa The bell tower was conceived as independent of these prototypes and, to a greater extent, was independently designed and developed on the basis of the architectural experience of its predecessors, resulting in a unique Pisa style.

For example, the circular design of the bell tower was considered to correspond to the reflection of the cathedral building next to it, so it was deliberately imitated by the curved design of the semicircular apse of the church. More importantly, the bell tower is consistent with the emphasis on circular structures in the square, especially after the laying of the foundation stone of the magnificent, also circular baptistery, and the entire square is more intentionally designed to resemble the Anastasis of the Resurrection Church in Jerusalem. modern version. This kind of design is derived from classic ancient architecture.

The decorative style of the bell tower inherits the classics of the cathedral and the baptistery. The walls are made of marble or limestone with two dark and light white bands, half-exposed square column arches, and carved doors in the arcades. , long rhombus-shaped flat roof, and the wall above the arcade form a strong contrast between the bright surface and the shaded surface when exposed to sunlight, giving the illusion that the columns in the bell tower are quite heavy.

Visual continuity is created between the cathedral, baptistery and bell tower.

Extended information:

History and culture:

Galileo’s free fall experiment

Legend has it that in 1590, an Italian physicist was born in Pisa The scientist Galileo Galilei once conducted a free fall experiment on the Leaning Tower of Pisa. He dropped two spheres of different weights from the same height at the same time. As a result, the two shot balls landed almost at the same time. He thus discovered the law of free fall and overturned the previous Asian laws. Aristotle believed that heavier objects would reach the ground first, and the speed of falling objects would be proportional to their mass.

However, Galileo's two spheres did not fall together as in the legend. Even if the acceleration of gravity remains unchanged, the two spheres will not fall together due to the influence of air resistance. This is why goose feathers and shot put don't land together. Due to air resistance, the two spheres cannot be considered to be in free fall. But Galileo's experimental theory is correct. In a vacuum, objects regardless of their multiplicity follow the law of free fall.

The story of Galileo's free fall experiment at the Leaning Tower of Pisa is recorded in "The Historical Story of the Life of Galileo" written by his student Vincenzo Viviani (1622-1703) in 1654. (published in 1717), but Galileo, the University of Pisa, and others of his time had no record of this experiment. Historically, there have been two different opinions, for and against, as to whether Galileo Galileo conducted free fall experiments in the Leaning Tower of Pisa.

According to other records, a person conducted such an experiment on the Leaning Tower of Pisa in 1612, but he conducted this experiment to refute Galileo. The result was that the two balls did not reach the ground at the same time.

Reference materials:

Baidu Encyclopedia-Leaning Tower of Pisa