Galileo's Biography
Text by Megan Wilde. Plain text version edited by Ashley Fell for the Electronic Text Center. This biography is based upon information culled from The Galileo Project website.
Sections:
Early Life
Galileo and the Pendulum
Galileo On Motion
Galileo's Mechanical Devices
Galileo's Family Life
Galileo's Telescope
Galileo and the Inquisition
Galileo's Early Life
Galileo was born in Pisa, Italy
on February 15, 1564. His father, Vincenzo Galilei,
was a musician. Galileo's mother was Giulia degli Ammannati. Galileo was the
first of six (though some people believe seven) children. His family belonged
to the nobility but was not rich. In the early 1570's, he and his family moved
to Florence.
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The Pendulum
In 1581, Galileo began studying at the University of Pisa,
where his father hoped he would study medicine. While at the University of Pisa,
Galileo began his study of the pendulum
while, according to legend, he watched a suspended lamp swing back and forth
in the cathedral of Pisa. However, it was not until 1602 that Galileo made his
most notable discovery about the pendulum - the period (the time in which a
pendulum swings back and forth) does not depend on the arc of the swing (the
isochronism). Eventually, this discovery would lead to Galileo's further study
of time intervals and the development of his idea for a pendulum clock.
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On Motion
At the University of Pisa, Galileo learned the physics of
the Ancient Greek scientist, Aristotle. However, Galileo questioned the Aristotelian
approach to physics. Aristotelians believed that heavier objects fall faster
through a medium than lighter ones. Galileo eventually disproved this idea by
asserting that all objects, regardless of their density, fall at the same rate
in a vacuum. To determine this, Galileo performed various experiments in which
he dropped objects from a certain height. In one of his early experiments, he
rolled balls down gently sloping inclined plane and then determined their positions
after equal time intervals. He wrote down his discoveries about motion in his
book, De Motu, which means "On
Motion."
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Mechanical Devices
In 1592, Galileo was appointed professor of mathematics at
the University of Padua. While teaching there, he frequently visited a place
called the Arsenal, where Venetian ships were docked and loaded. Galileo had
always been interested in mechanical devices. Naturally, during his visits to
the Arsenal, he became fascinated by nautical technologies, such as the sector
and shipbuilding. In 1593, he was presented with the problem involving the placement
of oars in galleys. He treated the oar as a lever and correctly made the water
the fulcrum. A year later, he patented a model for a pump. His pump was a device that raised
water by using only one horse.
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Family Life
Galileo was never married. However, he did have a brief relationship
with Marina Gamba, a woman he met on one of his many
trips to Venice. Marina lived in Galileo's house in Padua where she bore him
three children. His two daughters, Virginia and Livia, were both put in convents
where they became, respectively, Sister Maria Celeste
and Sister Arcangela. In 1610, Galileo moved from Padua to Florence where he
took a position at the Court of the Medici family. He left his son, Vincenzio, with
Marina Gamba in Padua. In 1613, Marina married Giovanni Bartoluzzi, and Vincenzio
joined his father in Florence.
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Telescope
Galileo invented many mechanical devices other than the pump,
such as the hydrostatic balance. But perhaps his
most famous invention was the telescope. Galileo made his first
telescope in 1609, modeled after telescopes produced in other parts of Europe
that could magnify objects three times. He created a telescope later that same
year that could magnify objects twenty times. With this telescope, he was able
to look at the moon, discover the four satellites of Jupiter,
observe a supernova, verify the phases of Venus, and discover sunspots. His discoveries proved
the Copernican system which states
that the earth and other planets revolve around the sun. Prior to the Copernican
system, it was held that the universe was geocentric, meaning the sun revolved
around the earth.
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The Inquisition
Galileo's belief in the Copernican System eventually
got him into trouble with the Catholic Church. The Inquisition was a permanent institution in
the Catholic Church charged with the eradication of heresies. A committee of
consultants declared to the Inquisition that the Copernican proposition that
the Sun is the center of the universe was a heresy. Because Galileo supported
the Copernican system, he was warned by Cardinal Bellarmine, under order of Pope Paul
V, that he should not discuss or defend Copernican theories. In 1624, Galileo
was assured by Pope Urban VIII that he could write about Copernican
theory as long as he treated it as a mathematical proposition. However, with
the printing of Galileo's book, Dialogue Concerning the Two Chief World Systems,
Galileo was called to Rome in 1633 to face the Inquisition again. Galileo was
found guilty of heresy for his Dialogue, and was sent to his home near Florence
where he was to be under house arrest for the remainder of his life. In 1638,
the Inquisition allowed Galileo to move to his home in Florence, so that he
could be closer to his doctors. By that time he was totally blind. In 1642,
Galileo died at his home outside Florence.
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