Galileo Galilei

Galileo Galilei was an Italian physicist, mathematician and astronomer who has gone down in history as one of the greatest scientists of all time. Galileo showed an appreciation for Mathematics when he was studying Medicine at the University of Pisa and ended up becoming an important reference in fields such as Physics and Astronomy.

He discovered the satellites orbiting Jupiter and concluded, through astronomical observation, that the Copernican model, which held that the Earth orbited the Sun, was correct. He was persecuted by the Holy Inquisition for his positions as a scientist and forced to spend the last years of his life under house arrest.

Summary about Galileo Galilei

• Galileo Galilei was an important physicist, astronomer and mathematician of the Renaissance period .
• He entered the University of Pisa to study Medicine, but showed great interest in Mathematics.
• He invented the first thermometer, a kind of thermometer.
• He built his own telescope in 1609 and began to observe the Universe.
• He defended the Copernican model and was persecuted by the Inquisition .

Youth of Galileo Galilei

Galileo Galilei was born in Pisa , part of the Duchy of Florence at the time. His date of birth is February 15, 1564 . Son of Vincenzo Galilei, a lutenist (musician who played the lute), and of Giulia Ammannati, Galileo was a descendant of Galileo Bonaiuti, a famous physician from Pisa. He came from part of the family that abandoned “Bonaiuti” and adopted “Galilei” instead.

Galileo’s family moved to Florence when he was eight years old, but the young man remained living in Pisa, residing in his tutor’s house. In childhood, Galileo was able to build a number of important objects such as water mills, learned to play the lute and had good skill in the arts.

He spent time studying at a monastery, where he had access to content such as Grammar and Rhetoric. The young man even wanted to pursue an ecclesiastical career, but was convinced by his father to become a doctor. Vincenzo wanted his son to become a doctor because it was a more promising career, one that brought more financial returns.

Discoveries of Galileo Galilei

In 1581, Galileo was enrolled at the University of Pisa for a degree in Medicine . However, throughout the course, Galileo showed less interest in Medicine and more in Mathematics. A remarkable event in his university career was to observe a chandelier that swung from side to side due to the force of the wind.

He observed the phenomenon, replicated it in his home, and identified the law of the pendulum , finding that a pendulum takes the same amount of time to swing between two sides. Galileo’s interest in mathematics was reinforced when he mistakenly attended a lecture by Ostilio Ricci, a professor at the University of Pisa .

Galileo’s father did not agree with his son’s involvement with Mathematics, but he was eventually convinced and allowed him to study what he wanted. Galileo Galilei began to study with Ostilio Ricci, proving to be an excellent student. However, he did not complete the course and left the university in 1585 .

After dropping out of the course, Galileo supported himself for a while by teaching Mathematics to students and began to look for opportunities at universities. In 1589 he got a three-year contract to work at the University of Pisa, and an event marked him during this period.

He was able to prove that a theory that had held up since Aristotle ‘s time was incorrect . This theory claimed that heavier-mass objects fell faster toward the ground than lighter-mass objects. Many biographies of Galileo claim that he climbed to the top of the Leaning Tower of Pisa to prove this theory incorrect.

In this experiment, he would have launched two objects from the top of the tower, one object being lighter than the other. Both reached the ground at the same time, thus proving that Aristotle’s theory was incorrect. However, many historians claim that this experiment would not have happened.

In 1592, Galileo moved to Padua , where he worked at the University of Padua, teaching subjects such as Geometry and Astronomy. During the period he was in the city, Galileo conducted innovative studies that led him to manufacture important objects, one of which was a kind of thermometer, the first object capable of measuring temperature in history.

This rudimentary thermometer became known as a thermoscope . Another significant invention of his was a kind of compass, widely used by the military until the mid-19th century. The creation of these objects allowed Galileo to earn extra income.

• Galileo Galilei and Astronomy

All the work developed by Galileo Galilei ensured that his name stood out among the intellectuals of the Italian peninsula. The great achievements of his academic and scientific career were in the field of Astronomy, starting with the construction of a telescope in 1609.

He decided to build his own telescope after word got around that Hans Lippershey, a Dutch eyeglass maker, had invented this device. Galileo managed to develop a telescope three times more powerful than Lippershey’s. Later, the physicist produced a device ten times more powerful.

With the telescope in hand, Galileo began his studies in the field of astronomy, which enjoyed enormous popularity. He began to make astronomical observations and identified, for example, that the surface of the moon was completely different from what was imagined, having many imperfections, craters, etc.

Galileo also devoted himself to observing Jupiter , from a telescope improved by 30 times. The astronomer’s observations led him to realize that the planet was surrounded by small stars. Later, he realized that they were not stars, but small satellites orbiting Jupiter.

From this observation, Galileo began to question the Ptolemaic model , which declared that the Earth was the center of the Universe and that the other planets revolved around it. The astronomer agreed with the theory proposed by Nicolaus Copernicus : in fact, the Sun was the center of the Universe.

Galileo Galilei carried out other observations on planets such as Venus, Neptune and Saturn. These observations reinforced Galileo’s position that the planets orbited the Sun. The defense of this position was a risk for him, since the thought recognized by the Catholic Church at the time was that the Sun and the planets orbit the Earth.

Galileo’s Problems with the Church

Galileo ‘s position in defense of heliocentrism caught the attention of the Church. Those who were more religious began to contest the studies promoted by him. The questions made to Galileo were based on biblical verses, such as Psalm 93:1, which mentioned that the “world is established”, or Joshua 10:13, which stated that the “Sun has stopped”.

At one point, a follower of Galileo was asked by a woman named Christina of Florence about her tutor’s ideas. The astronomer decided to send her a letter presenting arguments that proved her position on heliocentrism. Galileo’s letter was read by many at the time, which gave more repercussion to his work.

One of the phrases stated that the Bible was the basis for faith and morals, but not for science. In 1615, Galileo was denounced to the Inquisition for heresy for refuting the Ptolemaic model. The investigation that followed did not lead to the conviction of the physicist, but he was instructed not to defend the heliocentric theory any longer. In addition, Copernicus’ books and other heliocentric works were banned by the Church.

Galileo’s situation was complicated in 1632, when he published a book called Dialogue Concerning the Two Major World Systems . In that book, he compared, through a dialogue, the Copernican (heliocentrism) and Ptolemaic (geocentrism) systems. The book was very successful, but it bothered the Church’s greatest authority, Pope Urban VIII.

Galileo’s work was interpreted as tending to defend the Copernican system, since the character defending the Ptolemaic model was constantly placed in contradiction. Galileo was again accused by the Inquisition and went to Rome in 1633 to defend himself. He was even threatened with torture and was told to admit that his book could lead people to understand his message as a defense of Copernican ideas.

Galileo’s ruling, on June 22, 1633, stated that he should publicly deny Copernicus’ ideas and the heliocentric model. The astronomer was also sentenced to life imprisonment , and his book was banned.

A popular account has become popular that after publicly denying heliocentrism, Galileo muttered to himself “and yet he moves”, a reference to the fact that the Earth moved around the Sun.

Last years of Galileo Galilei

Galileo’s sentence defined what his last years were like. He was allowed to settle in his residence, which was on the outskirts of Florence, where he remained until his death. He continued to study, but from 1638 onwards he became blind, in addition to suffering from other health problems that affected his quality of life.

Galileo Galilei died on January 8, 1642 . Publication of his banned book was not authorized again until 1822. Galileo’s pardon was issued by the Vatican in 1992, in an announcement that claimed he had done nothing wrong.

The physicist never married , but he had a lasting relationship with Marina Gamba, a woman with whom he had three children, named Virgínia, Maria and Vincenzo. Galileo’s children were considered illegitimate as he was not married to Marina. Galileo’s two daughters followed the ecclesiastical life. His son was legitimized in 1619 and followed his grandfather’s career, becoming a Lutheran.