Galileo Galilei

Galileo Galilei was born on February 15, 1564, in Pisa, Italy. Galileo was the
first of seven children of Vincenzio Galilei, a trader and Giula Ammannati, an
upper-class woman who married below her class. When Galileo was a young boy, his
father moved the family moved to Florence. Galileo moved into a nearby monastery
with the intentions of becoming a monk, but he left the monastery when he was 15
because his father disapproved of his son becoming a monk. In November of 1581,

Vincenzio Galilei had Galileo enrolled in the University of Pisa School of

Medicine because he wanted his son to become a doctor to carry on the family
fortune. Vincenzio thought that Galileo should be able to provide for the family
when he died, and his sister would need a dowry soon. Galileo had other plans,
and in early 1583 he began spending his time with the mathematics professors
instead of the medical ones. When his father learned of this, he was furious and
traveled 60 miles from Florence to Pisa just to confront his son with the
knowledge that he had been "neglecting his studies." The grand duke's
mathematician intervened and persuaded Vincenzio to allow Galileo to study
mathematics on the condition that after one year, all of Galileo's support would
be cut off and he was on his own. In the spring of 1585, Galileo skipped his
final exams and left the university without a degree. He began finding work as a
math tutor. In November of 1589, Galileo found a position as a professor of
mathematics at the university of Pisa, the same one he had left without a degree
four years before. Galileo was a brilliant teacher, but his radical ways of
thinking and open criticism of Aristotle's teachings were not acceptable to the
other professors at the university. They felt that he was too radical and that
his teachings were not suitable. In 1592, his three-year contract was not
renewed. 1n 1592, he landed a job teaching mathematics at the University of

Padua with the help of some aristocratic friends. After his father's death,

Galileo supported many relatives (including his brother Michelangelo and his
family) and the sum of money he earned as a professor was not nearly enough. He
began to tutor on the side to make extra money, including Prince Cosimo, the son
of Grand Duchess Christine of Tuscany, which helped Galileo with some of his
financial problems. This was also the year that Galileo met Marina Gamba, whom
he never married but had three children with. In 1604, Galileo's belief he had
found a new star - and his conclusion that the Earth was moving- began causing
him problems. The Roman Catholic Church was uneasy about this declaration that
they were wrong. The Church believed that all the planetary bodies were formed
at the beginning of Creation, and that new stars were impossible. In 1609,

Galileo heard of a "spyglass" that had been developed in Holland and
quickly constructed one himself - the first telescope of twenty times
magnification. Galileo presented the telescope to the senate of Venice in August
of 1609, who were so impressed they doubled his salary and gave him a permanent
job at the University of Padua. Galileo used his new device to observe the
heavens. He found that the popular belief that the moon was completely smooth
was incorrect; for he could see the craters and mountains with his new device.

In 1610, he observed four bodies around Jupiter which he concluded to be moons.

This was incredible proof against the theory of the time that the earth was the
center of the solar system because it was believed that all the planets and our
moon revolved around the earth. Since these four bodies apparently circled

Jupiter, this theory was put in question. Also through his telescope, Galileo
observed that the Milky Way was made up of thousands of stars and that could not
be seen with the naked eye. After observing Earth's moon and then finding the
four moons of Jupiter though his new device, he began to declare that the
findings of Aristotle and Ptolemy were wrong. Galileo believed that the
geocentric model was incorrect. Through lectures and writings, Galileo said that

Copernicus was right - that the earth moved around the sun. Galileo's enemies
took this declaration and used it against him. They went to the Vatican in Rome
and said that these ideas were heresy, because they went against the beliefs of
the Church. Of course, the Church sided with Galileo's accusers and in early

1616,