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Galileo Galeli was born on February 18, 1564 in Pisa, Italy. He was the oldest son to Vincenzo – a then well known musician and music theorist. His family moved to Florence in the early 1570s, where they had lived for years prior to Galileo’s birth. In the summer of 1581, Galileo set out to study medicine at the University of Pisa, but rather left in 1585 without any degree, due to both financial troubles and a more keen interest in mathematics and philosophy.
Galileo continued to experiment and publish findings to support him and released “La bilencetta” (“The Little Balance”) on hydrostatic principles after two decades of work. In 1588 he applied to be the chair of mathematics at the University of Bologna but was unsuccessful. In 1589 he was offered a position as chair of mathematics back at the University of Pisa as a result of this publication and his growing fame. This was a short post however, as he began to criticize Aristotle’s work on the nature of falling objects and published about this in “Du Motu”. Here is where Galileo made his famous velocity experiments by dropping objects off the Leaning Tower of Pisa to disprove Aristotle’s theory that heavier objects fall faster. To test this, Galileo used two objects of the same materials but differing masses to drop from the same height. He observed that they both landed at the same time (by 1609 he had determined that the distance fallen by a body is proportional to the square of elapsed time, and that the trajectory of a projectile is a parabola). These non-Aristotelian views were not popular with the public or his surrounding academic community, and his contract was not renewed in 1592. This poor luck almost immediately followed the loss of his father in 1591.
Fortunately, in that same year, Galileo found himself a more permanent position teaching geometry, mechanics, and astronomy at the University of Padua. This new job helped him support himself and his younger brother, Michelangelo, who he was charged with taking care of after his father’s death.
Once settled at work, and now a father of two girls, Galileo continued his research and publications. In 1604, he published “The Operations of a Geometrical and Military Compass”. He also invented a hydrostatic balance for measuring small objects. In that same year, he refined his theories on motion of falling objects and developed his universal law of acceleration, which applied to all objects in the universe. As if this were not enough, he also began to publically support the Copernican theory of heliocentrism – the notion that the earth and planets rotate about the sun. Again this theory challenged Aristotle as well as the beliefs of the Catholic Church. In 1606 he also became the father of his third child - a boy.
Galileo continued to experiment and publish findings to support him and released “La bilencetta” (“The Little Balance”) on hydrostatic principles after two decades of work. In 1588 he applied to be the chair of mathematics at the University of Bologna but was unsuccessful. In 1589 he was offered a position as chair of mathematics back at the University of Pisa as a result of this publication and his growing fame. This was a short post however, as he began to criticize Aristotle’s work on the nature of falling objects and published about this in “Du Motu”. Here is where Galileo made his famous velocity experiments by dropping objects off the Leaning Tower of Pisa to disprove Aristotle’s theory that heavier objects fall faster. To test this, Galileo used two objects of the same materials but differing masses to drop from the same height. He observed that they both landed at the same time (by 1609 he had determined that the distance fallen by a body is proportional to the square of elapsed time, and that the trajectory of a projectile is a parabola). These non-Aristotelian views were not popular with the public or his surrounding academic community, and his contract was not renewed in 1592. This poor luck almost immediately followed the loss of his father in 1591.
Fortunately, in that same year, Galileo found himself a more permanent position teaching geometry, mechanics, and astronomy at the University of Padua. This new job helped him support himself and his younger brother, Michelangelo, who he was charged with taking care of after his father’s death.
Once settled at work, and now a father of two girls, Galileo continued his research and publications. In 1604, he published “The Operations of a Geometrical and Military Compass”. He also invented a hydrostatic balance for measuring small objects. In that same year, he refined his theories on motion of falling objects and developed his universal law of acceleration, which applied to all objects in the universe. As if this were not enough, he also began to publically support the Copernican theory of heliocentrism – the notion that the earth and planets rotate about the sun. Again this theory challenged Aristotle as well as the beliefs of the Catholic Church. In 1606 he also became the father of his third child - a boy.
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In 1609 Galileo took up a fascination with a telescope built by a Dutch eyeglass maker, and set out to make his own that was said to be about 20 times more powerful than the original model. Interestingly enough, he got the materials from lenses for sale in eyeglass shops and was very quick to teach himself how to lens grind to improve the magnification of the telescopes. His device was presented to the Venetian Senate and Galileo was promised life tenure and a doubled salary. These devices were first used for navigation and ship spotting, but Galileo wished for more. He turned his device to space one day in the fall and was able to observe detail of the moon’s surface finding that it was not flat, but rather had many elevation features. Over the next several months he sketched the phases of the moon as he observed them. In January of 1610 he discovered four moons orbiting Jupiter, that more stars were visible through his telescope, and that Venus had phases like the moon (proving it rotated about the sun) and resultantly published “Sidereus Nuncius” (“The Sidereal Messenger”) to describe his recent discoveries.
Galileo’s consequent work continued to disprove Aristotle’s previous findings, and contradicted the Catholic Church’s doctrine. The acknowledgement of the moons of Jupiter showed that there had to be more than one center of motion in the universe, and the phases of Venus showed that it revolves around the sun. This was self-confirming for Galileo, that Copernicus’ ideas that the sun is the center of the universe and that the Earth is a planet must be true. Galileo’s subscription to Copernicanism was a major milestone in scientific development.
In 1612 he published his explanations of buoyancy relating to density rather than shape. The year following he published on the observations of sunspots, refuting Aristotle’s beliefs that the sun was perfect. In this same year, he explained to a student of his, Benedetto Castelli, that Copernican theory did not contradict the church, but that science provided a more accurate view. It is said that some of Galileo’s enemies sent inaccurate copies of this letter to the Inquisition in Rome. Galileo had to send an accurate copy, but regardless, in 1616, once the church had gotten a hold of this, Galileo was labeled a heretic and was banned from teaching his ways regarding planetary motion, despite his efforts to defend his position. He lived by the orders for seven years.
Struggling with these setbacks, Galileo entered into a debate through a student over the nature of comets in 1618. After a number of exchanges, most with Orazio Grassi, a mathematics professor at Collegio Romano, he eventually admitted to being responsible for his statements and rebuttals. The publication, “Il Saggiatore” (“The Assayer”) was published in 1623, discussing the philosophic development of science at the time. It contained mathematical and descriptive explanations of Galileo’s recent discoveries. It was written intentionally in such a way that only people with scientific knowledge would understand its contents.
Conveniently, also in 1623, Galileo’s friend and admirer, Maffeo Cardinal Barberini was named Pope Urban VIII. As “Il Saggiatore” was going to press, Galileo’s friends arranged to have it dedicated to Mr. Barberini. Galileo was permitted and encouraged to continue his research on astronomy by the new pope, but only if it were guaranteed to be objective and not in favour of Copernican theory. A publication was made by Galileo that was interpreted to lean in favour of Copernicus and against Aristotle entitled, “Dialogo sopra i due massimi sistemi del mondo, tolemaico e copernicano” (“Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican”) completed in 1630. Galileo diplomatically sent it to a Roman Censor who forwarded a number of harsh criticisms of the book to his colleagues in Florence. The Florentine censors heeded Galileo’s preface explaining his hypothetical position and the work, fortunately or unfortunately, was published.
Galileo’s consequent work continued to disprove Aristotle’s previous findings, and contradicted the Catholic Church’s doctrine. The acknowledgement of the moons of Jupiter showed that there had to be more than one center of motion in the universe, and the phases of Venus showed that it revolves around the sun. This was self-confirming for Galileo, that Copernicus’ ideas that the sun is the center of the universe and that the Earth is a planet must be true. Galileo’s subscription to Copernicanism was a major milestone in scientific development.
In 1612 he published his explanations of buoyancy relating to density rather than shape. The year following he published on the observations of sunspots, refuting Aristotle’s beliefs that the sun was perfect. In this same year, he explained to a student of his, Benedetto Castelli, that Copernican theory did not contradict the church, but that science provided a more accurate view. It is said that some of Galileo’s enemies sent inaccurate copies of this letter to the Inquisition in Rome. Galileo had to send an accurate copy, but regardless, in 1616, once the church had gotten a hold of this, Galileo was labeled a heretic and was banned from teaching his ways regarding planetary motion, despite his efforts to defend his position. He lived by the orders for seven years.
Struggling with these setbacks, Galileo entered into a debate through a student over the nature of comets in 1618. After a number of exchanges, most with Orazio Grassi, a mathematics professor at Collegio Romano, he eventually admitted to being responsible for his statements and rebuttals. The publication, “Il Saggiatore” (“The Assayer”) was published in 1623, discussing the philosophic development of science at the time. It contained mathematical and descriptive explanations of Galileo’s recent discoveries. It was written intentionally in such a way that only people with scientific knowledge would understand its contents.
Conveniently, also in 1623, Galileo’s friend and admirer, Maffeo Cardinal Barberini was named Pope Urban VIII. As “Il Saggiatore” was going to press, Galileo’s friends arranged to have it dedicated to Mr. Barberini. Galileo was permitted and encouraged to continue his research on astronomy by the new pope, but only if it were guaranteed to be objective and not in favour of Copernican theory. A publication was made by Galileo that was interpreted to lean in favour of Copernicus and against Aristotle entitled, “Dialogo sopra i due massimi sistemi del mondo, tolemaico e copernicano” (“Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican”) completed in 1630. Galileo diplomatically sent it to a Roman Censor who forwarded a number of harsh criticisms of the book to his colleagues in Florence. The Florentine censors heeded Galileo’s preface explaining his hypothetical position and the work, fortunately or unfortunately, was published.
![Picture](/uploads/5/4/0/2/54029697/5902899.jpg?250)
Backlash to the publication was quick. The pope struck a special review committee to the publication who found that Galileo’s statements and claims were not hypothetical, as he had promised. As a result, Galileo was summoned to Rome for an inquisition that lasted from September 1632 to July 1633. The first part of this trial before the Inquisition went back as far as 1616 when the accusers pointed out that Galileo had been ordered not to discuss Copernican theory. As defence, he showed a letter from Cardinal Bellarmine (then deceased) that he was warned only not to hold or defend the theory. This did not hold, and Galileo ended up admitting to having overstated the case.
Most of this inquisition was very civil whereby Galileo was treated with the utmost respect, but finally, to get the answers they truly wanted, he was threatened with torture. To avoid such punishment, Galileo admitted to supporting Copernicus’ theories, though he personally still felt that his ideas were correct. Convicted of heresy, Galileo spent his formative years under imprisonment and house arrest. He was ordered not to publish outside of Italy and not to have any visitors, both commands he disregarded. As he was convicted, Galileo was fabled to have whispered, “Eppur si muove” (“And yet it moves”).
When the process was complete, Galileo spent six months in the palace of Ascanio Piccolomini, the archbishop of Siena. He then made his final move to a villa in Arcetri, in the hills above Florence where he would spend the rest of his days. His daughter, Sister Maria Celeste, at a nearby nunnery, brought company and comfort to him until her unexpected death in 1634. At this point, Galileo was 70 years old but continued working.
Most of this inquisition was very civil whereby Galileo was treated with the utmost respect, but finally, to get the answers they truly wanted, he was threatened with torture. To avoid such punishment, Galileo admitted to supporting Copernicus’ theories, though he personally still felt that his ideas were correct. Convicted of heresy, Galileo spent his formative years under imprisonment and house arrest. He was ordered not to publish outside of Italy and not to have any visitors, both commands he disregarded. As he was convicted, Galileo was fabled to have whispered, “Eppur si muove” (“And yet it moves”).
When the process was complete, Galileo spent six months in the palace of Ascanio Piccolomini, the archbishop of Siena. He then made his final move to a villa in Arcetri, in the hills above Florence where he would spend the rest of his days. His daughter, Sister Maria Celeste, at a nearby nunnery, brought company and comfort to him until her unexpected death in 1634. At this point, Galileo was 70 years old but continued working.
![Picture](/uploads/5/4/0/2/54029697/3222938.jpg?207)
In Siena Galileo had begun writing about motion and the strengths of materials – two interests of his that had been previously disrupted by his work on the telescope. This work was ultimately published in the Netherlands in 1638 under the title, “Discorsi e dimostrazioni matematiche intorno a due nuove scienze attenenti alla meccanica” (“Dialogues Concerning Two New Sciences”). These manuscripts contained information including experiments and mathematics of motion, including the laws of falling bodies, as well as the parabolic path by which projectiles travel as a result of mixing of uniform motion and acceleration, and were written with Galileo’s opinions being presented in the third person by a character named Salviati. By the time these were published in 1638, Galileo was blind and in ill health. In 1640, he wrote to a colleague: “Not without envy I have heard of your going back to Padua, where I spent the best 18 years of my life (“li diciotto anni migliori di tutta la mia eta”). Do enjoy the freedom and friendship that you have found there and in the magnificent city of Venice.”
Galileo died in Arcetri, Italy on January 8, 1642 with a student of his, Vincenzo Viviani beside him. Unfortunately he did not live to see the church’s eventual acceptance of his and related works. In 1758 the bans were lifted from Copernican Theory and by 1835 opposition to heliocentrism was eliminated.
Into the 20th century, popes even acknowledged the great works of Galileo. In 1992, Pope John Paul II went so far as to make a statement of regret surrounding the unfair treatment of Galileo.
Galileo’s phenomenal discoveries and mathematical treatment of so many scientific topics are exactly what earned him the title “The Father of Modern Science.”
For those of you who prefer the condensed, video version, please check this out:
Galileo died in Arcetri, Italy on January 8, 1642 with a student of his, Vincenzo Viviani beside him. Unfortunately he did not live to see the church’s eventual acceptance of his and related works. In 1758 the bans were lifted from Copernican Theory and by 1835 opposition to heliocentrism was eliminated.
Into the 20th century, popes even acknowledged the great works of Galileo. In 1992, Pope John Paul II went so far as to make a statement of regret surrounding the unfair treatment of Galileo.
Galileo’s phenomenal discoveries and mathematical treatment of so many scientific topics are exactly what earned him the title “The Father of Modern Science.”
For those of you who prefer the condensed, video version, please check this out: