The Leaning Tower of Pisa (Italian: Torre pendente di Pisa or Torre di Pisa, English: Leaning Tower of Pisa), constructed in August 1173, is the freestanding bell tower of the cathedral of the city of Pisa, Italy, located in the Piazza del Mirador (Square of Miracles) on the north side of the city of Pisa in the province of Tuscany, Italy.

The Piazza del Miracle's large lawn is scattered with a group of religious buildings, the Duomo (built 1063-13th century), the Baptistery (built 1153-14th century), the Bell Tower (known as the Leaning Tower of Pisa), and the Cenotaph (built 1174), whose fa?ades are all of cream-colored marble The Leaning Tower of Pisa is located on the site of the Pisa Cathedral. 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, and 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, with a total weight of about 14,453 tons, and the center of gravity is 22.6 meters above the foundation. The area of the circular foundation is 285 square meters and the average pressure on the ground is 497 kPa. The angle of inclination is 3.99 degrees, deviating 2.5 meters from the outer edge of the foundation, and the top floor protrudes 4.5 meters.The inclination was first noticed in 1174.

Architecture:

The Leaning Tower of Pisa is undoubtedly an important building in the history of architecture. Its bold circular architectural design had already shown its originality to the world before the severe tilt occurred.

While it is not uncommon to find Italian bell towers of an earlier date with circular foundations - similar examples can be found in Ravenna, Tuscany and Umbria - the Pisa bell tower is considered to be independent of these prototypes, and to a greater extent it was designed and developed independently of its predecessors, taking into account their experience of building in a circular form, which gave it its distinctive Pisa style.

For example, the circular design of the bell tower is thought to correspond to the reflection of the cathedral building next to it, and therefore intentionally mimics the curved design of the semi-circular nave of the church. More importantly, the bell tower is in keeping with the emphasis on circular structures in the square, especially after the laying of the foundation stone of the magnificent, also circular, Baptistery, which was intentionally designed to be a modern version of the Church of the Resurrection (Anastasis) in Jerusalem. The design is derived from classic ancient architecture.

The decorative style of the bell tower inherits the classics of the Cathedral and the Baptistery, with walls of marble or limestone in two shades of white, half-exposed square columns of the arches, carved gates in the arcades, long diamond-shaped latticework of flat ceilings, and walls above the arcades that create a strong contrast of light and shade from sunlight, creating the illusion that the columns inside the bell tower are quite heavy.

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

Extended Information:

History and Culture:

Galileo's Free Fall Experiment

Legend has it that in 1590, Galileo, an Italian physicist who was born in the city of Pisa, did a free-fall experiment on the Leaning Tower of Pisa by dropping two spheres with different weights from the same height At the same time thrown down, the result of the two lead balloon almost at the same time to the ground, thus discovering the law of free fall, overthrowing the previous Aristotelian view that the heavy object will reach the ground first, the speed of the falling body is proportional to the mass of the point of view.

But Galileo's two spheres did not fall together as legend has it; even if the acceleration of gravity were constant, the two spheres were affected by air resistance and would not fall together. That's why the quill and the lead ball won't land together. Due to air resistance, the two spheres cannot be seen as in free fall. But Galileo's experimental theory is correct; in a vacuum, objects, no matter how heavy, follow the law of free fall.

The story of Galileo's free-fall experiment at the Leaning Tower of Pisa is recorded in the book The Historical Story of the Life of Galileo (published in 1717), written in 1654 by his pupil Vincenzo Viviani (1622-1703), but there is no record of this experiment by Galileo, the University of Pisa, or by any of his contemporaries. There is no record of this experiment. There have been two different historical views for and against whether Galileo did the free-fall experiment at the Leaning Tower of Pisa.

On the other hand, it is recorded that a man did such an experiment on the Leaning Tower of Pisa in 1612, but he did it to refute Galileo, and the result was that the two balls did not reach the ground at the same time.

Reference:

Baidu Encyclopedia - The Leaning Tower of Pisa