Galileo Galilei

Galileo Galilei

1 . Synopsis

Born on February 15, 1564, in Pisa, Italy, Galileo Galilei was a mathematics professor who made pioneering observations of nature with longlasting implications for the study of physics. He also constructed a telescope and supported the Copernican theory, which supports a suncentered solar system. Galileo was accused twice of heresy by the church for his beliefs, and wrote books on his ideas. He died in Arcetri, Italy, on January 8, 1642.

2 . Early Life

Galileo Galilei was born on February 15, 1564, in Pisa in the Duchy of Florence, Italy. He was the first of six children born to Vincenzo Galilei, a wellknown musician and music theorist, and Giulia Ammannati. In 1574, the family moved to Florence, where Galileo started his formal education at the Camaldolese monastery in Vallombrosa.

In 1583, Galileo entered the University of Pisa to study medicine. Armed with high intelligence and talent, he soon became fascinated with many subjects, particularly mathematics and physics. While at Pisa, Galileo was exposed to the Aristotelian view of the world, then the leading scientific authority and the only one sanctioned by the Roman Catholic Church. At first, Galileo supported this view, like any other intellectual of his time, and was on track to be a university professor. However, due to financial difficulties, Galileo left the university in 1585 before earning his degree.

3 . Academic Career

Galileo continued to study mathematics, supporting himself with minor teaching positions. During this time he began his twodecade study on objects in motion and published The Little Balance, describing the hydrostatic principles of weighing small quantities, which brought him some fame. This gained him a teaching post at the University of Pisa, in 1589. There Galileo conducted his fabled experiments with falling objects and produced his manuscript Du Motu (On Motion), a departure from Aristotelian views about motion and falling objects. Galileo developed an arrogance about his work, and his strident criticisms of Aristotle left him isolated among his colleagues. In 1592, his contract with the University of Pisa was not renewed.

Galileo quickly found a new position at the University of Padua, teaching geometry, mechanics and astronomy. The appointment was fortunate, for his father had died in 1591, leaving Galileo entrusted with the care of his younger brother Michelagnolo. During his 18year tenure at Padua, he gave entertaining lectures and attracted large crowds of followers, further increasing his fame and his sense of mission.

4 . Controversial Findings

In 1604, Galileo published The Operations of the Geometrical and Military Compass, revealing his skills with experiments and practical technological applications. He also constructed a hydrostatic balance for measuring small objects. These developments brought him additional income and more recognition. That same year, Galileo refined his theories on motion and falling objects, and developed the universal law of acceleration, which all objects in the universe obeyed. Galileo began to express openly his support of the Copernican theory that the earth and planets revolved around the sun. This challenged the doctrine of Aristotle and the established order set by the Catholic Church.

July 1609, Galileo learned about a simple telescope built by Dutch eyeglass makers, and he soon developed one of his own. In August, he demonstrated it to some Venetian merchants, who saw its value for spotting ships and gave Galileo salary to manufacture several of them. However, Galileos ambition pushed him to go further, and in the fall of 1609 he made the fateful decision to turn his telescope toward the heavens. In March 1610, he published a small booklet, The Starry Messenger, revealing his discoveries that the moon was not flat and smooth, but a sphere with mountains and craters. He found Venus had phases like the moon, proving it rotated around the sun. He also discovered Jupiter had revolving moons, which didnt revolve around the earth.Soon Galileo began mounting a body of evidence that supported Copernican theory and contradicted Aristotle and Church doctrine. In 1612, he published his Discourse on Bodies in Water, refuting the Aristotelian explanation of why objects float in water, saying that it wasnt because of their flat shape, but instead the weight of the object in relation to the water it displaced. In 1613, he published his observations of sunspots, which further refuted Aristotelian doctrine that the sun was perfect. That same year, Galileo wrote a letter to a student to explain how Copernican theory did not contradict Biblical passages, stating that scripture was written from an earthly perspective and implied that science provided a different, more accurate perspective. The letter was made public and Church Inquisition consultants pronounced Copernican theory heretical. In 1616, Galileo was ordered not to

5 . Reaction by the Church

Church reaction against the book was swift, and Galileo was summoned to Rome. The Inquisition proceedings lasted from September 1632 to July 1633. During most of this time, Galileo was treated with respect and never imprisoned. However, in a final attempt to break him, Galileo was threatened with torture, and he finally admitted he had supported Copernican theory, but privately held that his statements were correct. He was convicted of heresy and spent his remaining years under house arrest. Though ordered not to have any visitors nor have any of his works printed outside of Italy, he ignored both. In 1634, a French translation of his study of forces and their effects on matter was published, and a year later, copies of the Dialogue were published in Holland. While under house arrest, Galileo wrote Two New Sciences, a summary of his lifes work on the science of motion and strength of materials. It was printed in Holland in 1638. By this time, he had become blind and in ill health.

6 . Personal Life

In 1600, Galileo met Marina Gamba, a Venetian woman, who bore him three children out of wedlock: daughters Virginia and Livia, and son Vincenzo. He never married Marina, possibly due to financial worries and possibly fearing his illegitimate children would threaten his social standing. He worried the two girls would never marry well, and when they were older, had them enter a convent. His sons birth was eventually legitimized and he became a successful musician.

7 . Law of the Pendulum

At age twenty, Galileo noticed a lamp swinging overhead while he was in a cathedral. Curious to find out how long it took the lamp to swing back and forth, he used his pulse to time large and small swings. Galileo discovered something that no one else had ever realized: the period of each swing was exactly the same. The law of the pendulum, which would eventually be used to regulate clocks , made Galileo Galilei instantly famous.

Except for mathematics, Galileo Galilei was bored with university. Galileos family was informed that their son was in danger of flunking out. A compromise was worked out, where Galileo would be tutored fulltime in mathematics by the mathematician of the Tuscan court. Galileos father was hardly overjoyed about this turn of events, since a mathematicians earning power was roughly around that of a musician, but it seemed that this might yet allow Galileo to successfully complete his college education. However, Galileo soon left the University of Pisa without a degree.

8 . Mathematics

To earn a living, Galileo Galilei started tutoring students in mathematics. He did some experimenting with floating objects, developing a balance that could tell him that a piece of, say, gold was 19.3 times heavier than the same volume of water. He also started campaigning for his lifes ambition: a position on the mathematics faculty at a major university. Although Galileo was clearly brilliant, he had offended many people in the field, who would choose other candidates for vacancies.

9 . Dantes Inferno

Ironically, it was a lecture on literature that would turn Galileos fortunes. The Academy of Florence had been arguing over a 100yearold controversy: What were the location, shape, and dimensions of Dantes Inferno Galileo Galilei wanted to seriously answer the question from the point of view of a scientist. Extrapolating from Dantes line that [the giant Nimrods] face was about as long And just as wide as St. Peters cone in Rome, Galileo deduced that Lucifer himself was 2,000 armlength long. The audience was impressed, and within the year, Galileo had received a threeyear appointment to the University of Pisa, the same university that never granted him a degree.

10 . The Leaning Tower of Pisa

At the time that Galileo arrived at the University, some debate had started up on one of Aristotles laws of nature, that heavier objects fell faster than lighter objects. Aristotles word had been accepted as gospel truth, and there had been few attempts to actually test Aristotles conclusions by actually conducting an experiment.According to legend, Galileo decided to try. He needed to be able to drop the objects from a great height. The perfect building was right at handthe Tower of Pisa, 54 meters tall. Galileo climbed up to the top of the building carrying a variety of balls of varying size and weight, and dumped them off of the top. They all landed at the base of the building at the same time (legend says that the demonstration was witnessed by a huge crowd of students and professors). Aristotle was wrong.

However, Galileo Galilei continued to behave rudely to his colleagues, not a good move for a junior member of the faculty. Men are like wine flasks, he once said to a group of students. …look at….bottles with the handsome labels. When you taste them, they are full of air or perfume or rouge. These are bottles fit only to pee into!Not surprisingly, the University of Pisa chose not to renew Galileos contract.