Article abstract: Galileo helped establish the modern scientific method through his use of observation and experimentation. His work in mathematics, physics, and astronomy made him a leading figure of the early scientific revolution.
Galileo Galilei was the first of seven children born to Vincenzo Galilei and Giulia Ammanati. His father was a cloth merchant as well as a noted musician who wrote several treatises on musical theory. The Galileis were a noble Florentine family that over the years had lost much of its wealth. It was for financial reasons that Vincenzo left Florence and moved to Pisa to establish his textile trade.
At the age of ten, Galileo and his family returned to Florence. His early education was directed by his father with the help of a private tutor. He also spent some time at the monastery of Santa Maria di Vallombrosa. The content of Galileo’s elementary education is unknown, but it was probably humanistic in character. His father urged him to pursue university studies which would lead to a lucrative profession.
Following his father’s wish, Galileo enrolled as a student of medicine at the University of Pisa in 1581. He showed little interest in his medical studies; it was mathematics that captured his attention. A year after enrolling at the university, Galileo made his legendary discovery of the isochronal movement of pendulums by observing a chandelier in the Pisa cathedral. He confirmed his theory regarding the equal movement of pendulums by conducting a series of experiments. He continued an independent study of science and mathematics, finally convincing his father to allow him to abandon his medical studies. Galileo withdrew from the University of Pisa in 1586 without receiving a degree, and he returned to his family.
Upon his return to Florence, Galileo studied a wide range of literary and scientific texts. In addition, he delivered a series of popular lectures on the Inferno of Dante’s La divina commedia (c. 1320; The Divine Comedy, 1802) at the Florentine Academy. In 1589, he used the influence of friends to obtain an appointment as a lecturer of mathematics at the University of Pisa. His return to Pisa marked a productive and enjoyable time for the young scholar. He conducted a series of experiments relating to falling bodies and wrote a short manuscript which challenged many traditional and generally accepted teachings about physics. In addition to his scholarly activities, Galileo was known for his quick wit, biting sense of humor, and excellent debating ability. Once again his friends intervened on his behalf to arrange an appointment, in 1592, to a more prestigious chair of mathematics at the University of Padua.
It was at Padua that Galileo began his life’s work, which would bring him both fame and controversy. He quickly established himself as an excellent and popular teacher, both in terms of public lectures and private tutoring. He also wrote a series of short manuscripts on a variety of technical and practical issues. In 1597, he constructed a “military compass” to assist artillery bombardments and army formations.
Although Galileo’s invention of the military compass brought him acclaim and a good source of additional income, it was his work in the study of motion and astronomy that firmly established his reputation as a leading scientist. In 1604, a new star could be seen, and its sudden appearance prompted a fierce debate. According to the dominant theory of the time, Earth was the immovable center of the universe. Based on the work of Aristotle and Ptolemy, most scholars believed that the planets, sun, and stars rotated around a stationary Earth. The universe was thought to reflect a perfect and unchangeable order that had been created by God. The new star raised a problem of how to account for its presence in an already complete and perfectly ordered universe.
The intensity of this debate reflected a larger controversy regarding the work of Nicolaus Copernicus. Copernicus claimed that Earth and the other planets orbited the sun, and the stars were fixed or stationary. The appearance of a new star provided a tangible point of reference to settle a much larger scientific and theological debate on the structure and nature of the universe. It was a debate Galileo wanted to enter. As his correspondence with the astronomer Johannes Kepler indicated, Galileo found Copernicus’ thesis convincing, but he lacked the necessary instrument to test the theory. This problem was remedied in 1609 when on a visit to Venice, Galileo learned about a new “eye-glass by means of which visible objects, though very distant from the eye, were distinctly seen as if nearby.” Based on this limited information, Galileo returned to Padua to design and build his own telescope.
With this new instrument, Galileo turned his gaze toward the sky. He saw that the moon was not a smooth sphere, as previously...
(The entire section is 2055 words.)