“Galileo was that guy who
invented the telescope.” This is what most people say when
they think about Galileo. However, Galileo did not even
invent the telescope; he only made improvements to it so it
could be used for astronomy. Galileo did use it to make
many important discoveries about astronomy, though; many
of these discoveries helped to prove that the sun was the
center of the galaxy. Galileo also made many important
contributions to Physics; he discovered that the path of a
projectile was a parabola, that objects do not fall with
speeds proportional to their weight, and much more. For
these discoveries, Galileo is often referred to as the founder
of modern experimental science. Galileo Galilei was born in
Pisa, Italy on February 15, 1564. Until he was about 10
years old, Galileo lived in Pisa; in 1574 the family moved to
Florence where Galileo started his education at
Vallombroso, a nearby monastery. In 1581, Galileo went to
the University of Pisa to study medicine, the field his father
wanted him to peruse. While at the University of Pisa,
Galileo discovered his interest in Physics and Mathematics;
he switched his major from medicine to mathematics. In
1585, he decided to leave the university without a degree to
pursue a job as a teacher. He spend four years looking for a
job; during this time, he tutored privately and wrote on some
discoveries that he had made. In 1589, Galileo was given the
job of professor of Mathematics at the University of Pisa.
His contract was not renewed in 1592, but received another
job at the University of Padua as the chair of Mathematics;
his main duties were to teach Geometry and Astrology.
Galileo taught at the university for eighteen years. Galileo
made many important discoveries from the time he was born
to when he left the University of Padua, 1564-1610. While
attending the University of Pisa, 1584, Galileo discovered
the principle of isochronism. Isochronism showed that the
period of a pendulum remains the same no matter what the
amplitude is. Galileo was said to have discovered this while
watching a chandelier swing in the cathedral next to the
Leaning Tower of Pisa. Galileo proved the isochronism of a
pendulum in 1602. He later used his discovery to design a
clock that used pendulums. While Galileo was looking for a
job after he left the University of Pisa, 1856, he invented the
hydrostatic balance. This was a device that found the
specific gravity of substances by weighing them under water.
This is what gave Galileo his first notice from the public.
Galileo also discovered that Aristotle’s belief that objects fall
at velocities proportional to their weight was wrong. He
found that all objects fall at the same rate; it is only the
density of the median they fall through that causes larger
objects to fall slower. He believed that all objects would fall
the same rate if they were in a vacuum. It is said Galileo
showed his students at the University of Pisa his discovery
by dropping a musket ball and a cannon ball at the same
time from the Leaning Tower of Pisa. Some scientists in an
article in New Scientist claim that Galileo was wrong in
saying that all objects fall at the same rate. They base their
calculations on the quantum theory. Particles in the objects
are constantly absorbing and releasing photons; this
absorbing and releasing changes the total energy that the
particles carry, which depends on temperature. This then
changes the inertial mass of the object. From this the
scientists concluded that heavier and cooler objects will fall
faster than those objects that are lighter and hotter. Although
this disproves what Galileo found, Galileo was still fairly
correct in his findings; the effect these scientists found is very
small. It is almost impossible to measure the difference in the
time it takes two objects of different weights to reach the
ground. (“Galileo Got it Wrong”, p. 36.) Galileo also made
many discoveries while he was teaching at the University of
Padua. Some of his little inventions were a calculating
compass, a thermometer, and a pump. One of his bigger
discoveries was that the path of a projectile was a parabola.
The parabola was due to the combined forces of horizontal
motion and vertical acceleration. He tested this by mounting
a chute on a table and letting the ball on it fly off the edge.
He then marked the spot where the ball landed. This became
very useful in the firing of ballisticas, guns, and rockets.
Another discovery Galileo made while he was at the
University of Padua was the “law of fall,” 1604. Galileo
explained the “law of fall” as “the spaces passed over in
natural motion are in proportion to the squares of the time.”
This is basically the acceleration of objects in a free fall.
Galileo based this law on Newton’s laws of motion. During
his last years at the University of Padua, Galileo heard about
a knew invention called the telescope. At Padua, he built a
telescope that was 20 times as powerful as the one that was
first invented. Galileo used this for astronomical purposes.
During the time this telescope was built, the belief of most
people, including the Catholic Church, was that the Earth
was the center of the universe. This view of the universe is
referred to as the Ptolemaic system. They also believed that
all things around the earth were perfect and unchanging.
There were some people who opposed the Ptolemaic
system; these people believed in the Copernican system.
This is where the sun is the center, rather than the sun.
Galileo believed in the Copernican system. When Galileo
pointed his telescope to the sky, he made many discoveries
that confirmed the Copernican system. One thing he found
was that the moon was not a perfect sphere as thought of in
the Ptolemaic system; it had craters and mountains not
visible to the human eye. Another discovery Galileo made
was that Jupiter had moons going around it. This conflicted
with the Ptolemaic system. It proved that the earth was not
the only planet with moons going around it. Galileo also
found that Venus had phases just like the Moon; this meant
that it had to be orbiting the sun. He also discovered that the
sun had spots on it that could be used to see how the earth
orbits around it. These discoveries all contradicted the
Ptolemaic system and confirmed the Copernican system. In
1610, Galileo started to publish his findings on the
Copernican system. The first publication of his findings was
in “The Starry Messenger.” The publications of Galileo’s
findings got him in a lot of trouble with the Catholic Church.
In 1616, Galileo was summoned to Rome and band by the
Catholic Church to discuss the Copernican system. Galileo
followed the rule until 1632 when he published the “Dialogue
Concerning the Two Chief World Systems.” This article told
Galileo’s views of why the Copernican system was better
than the Ptolemaic system. Galileo was summoned to Rome
again and given life imprisonment under house arrest for
disobeying orders. The charge given to Galileo was very
unfair considering that he was right. In 1979, Pope John Paul
II wanted the Catholic Church to reverse the condemnation
of Galileo. In 1992, the Catholic Church admitted to their
error in condemning Galileo to house arrest. Galileo did not
give up his work because he was under house arrest. He
spent much of his time writing publications of his early work.
He had to sneak his publications to Holland to be printed,
though, because they were forbidden to be printed in Italy.
He wrote of Isochronism, the parabola path projectiles take,
the “law of fall”, and much more. In 1637, Galileo went
blind, but he found assistants to write for him. “Discourses
upon Two New Scientists” was one of the most known
articles that Galileo wrote during this time. Galileo also
worked on clock that used a pendulum to run during this
time. Galileo died in early January of 1642. As you see,
Galileo is much more than just a man who used a
astronomical telescope. Galileo made many important
discoveries for the field of Physics; he opened the way for
scientists to combined Mathematic and Physics. He also
proved that the sun was the center of the galaxy. Galileo
deserved to be called the founder of modern experimental
science. Bibliography Dunn, Travis. Galileo Biography.
Http:/es.rice.edu/ES/ humsoc/Galileo/index.html. 23 January
1996. Field, J.V. Galileo Galilei.
August 1995. “Galileo Got it Wrong.” New Scientist. 4 June
1987, p. 36. MacKeith, Bill. “Galileo Galilei.” The Classical
Scientists. Southside Ltd. Edinburgh, England. 1989. vol.
15, pp. 25-44. O’Malley, Charles D. “Galileo.” The New
Encyclopedia Britannica. Encyclopedia Britannica Inc.
Chicago, Illinois. 1989. vol. 19, pp. 640-642. Stillman,
Drake. The Life of Galileo Galilei. http://www.
owlnet.rice.edu/-jessdave/Galileo2.html. 1980. Stillman,
Drake. “Galileo.” Microsoft Encarta. Copyright 1994
Microsoft Corp. Copyright 1994 Funk ; Wagnalls Corp.
Stillman, Drake. “Galileo.” The World Book Encyclopedia.
World Book Inc. London, England. 1995. vol. 8, pp.