The great Italian physicist and astronomer, Galileo Galilei, was born in the city of Pisa on February 15, 1564, to Vicenzo Galilei and Julia Ammanati di Pescia.
His father, although belonging to the nobility, was poor, but with a respected culture and a spirit that opposed prevailing ideas; he wanted a solid position for his son who, at age 17, was referred to the study of medicine as a lucrative profession. However, a medical career was not very attractive to Galileo and his restless spirit made him interested in other types of problems.
Galileo was still in his second year of medical school – which he never completed, as he found it uninteresting – when he discovered his vocation for mathematics and natural sciences. It is said that, once casually watching the oscillations of a chandelier in Pisa Cathedral, Galileo became interested in measuring the time of each oscillation, comparing it with the number of beats of his own pulse.
Surprised, he found that although the oscillations became smaller and smaller, the time of each oscillation always remained the same. Repeating the experiment in your home, using a pendulum made with a stone tied to a string, this result was confirmed, verifying that the time of an oscillation depended on the length of the thread. With this discovery he invented the pulsillogium, a kind of clock used to measure the pulse. This would be his last contribution to medicine.
The discovery of his true scientific vocation made him leave the university against his father's wishes, and he dedicated himself to new studies. In 1585, Galilei went to Florence, where he kept in touch with the intellectuals who frequented his father's house, which greatly enriched his philosophical and literary training.
Turning now to the study of the pendulum, Galileo found that, regardless of the weight of the body suspended in the end of a wire, the oscillation time is the same for both a light body and a body heavy.
This discovery led him to conclude that two stones of different sizes and weights would take the same amount of time. to fall, that is, to move from the highest position to the lowest position of the same trajectory. He then discovered that pendulum motion and free fall are caused by the same cause (gravity).
In addition to his work in the field of mechanics, Galileo contributed to the development of astronomy. Due to his great experimental ability, he built the first telescope for use in astronomical observations.
His observations led him to great discoveries that contradicted the philosophical and religious beliefs of the time, which were based on the teachings of Aristotle.
Galileo discovered that the planet Venus has phases like those of the moon, and this observation led him to conclude that the planet revolves around the Sun, as the astronomer Nicolas Copernicus stated in his heliocentric theory.
With that, he started to defend and spread the Copernicus theory, that the Earth, like the other planets, moves around the Sun. These ideas were presented in his Dialogues on the Two Great Systems of the World, published in 1632.
The publication of this work was condemned by the Church. In 1633, the Holy Inquisition arrested and tried Galileo for heresy.
To avoid being burned alive, Galileo Galilei was forced to deny his ideas through a confession, read aloud before the Holy Council of the Church.
“I, Galileo, son of the late Vincenzo Galilei, a seventy-year-old Florentine, personally summoned to the presence of this court and kneeling before you, Most Eminent and Most Reverend Cardinal Inquisitors General against heretical gravity throughout the Christian community, having before their eyes and touching the Holy Gospels, I swear that I have always believed that I believe, and, God's mercy, I will believe in the future, in everything that is defended, preached and taught by the Holy Catholic Church and Apostolic. But considering that (...) I wrote and printed a book in which I discuss the new doctrine (heliocentrism) already condemned and adduce arguments of great force in their favor, without presenting any solution for them, I went by the Holy Office accused of vehemently suspected of heresy, that is, of having held and believed that the Sun is at the center of the world and immobile, and that the Earth is not in the center, but moves; desiring to eliminate from the spirit of Your Eminences and of all faithful Christians this vehement suspicion conceived very justly against me, with sincerity and true faith, I abjure, curse and detest the aforementioned errors and heresies, and in general any other error, heresy and sect contrary to the Holy Church, and I swear that in the future I will never again say or affirm, verbally or in writing, anything that gives my respect."
Still, he was convicted and forced to remain under house arrest for the rest of his life.
It is said that after the verdict, Galileo uttered the following sentence: “eppur se muove” – “and yet she moves”.
Completely blind, Galileo died at his home, near Florence, on January 8, 1642.
By Kleber Cavalcante
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/fisica/galileu-ciencia-santa-inquisicao.htm