Born 15 Feb 1564 in Pisa, Duchy of Florence

Died 8 Jan 1642 at age 77 in Arcetri, Grand Duchy of Tuscany

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Biography

Galileo (Galilæi) de' Galilei is Notable.

Galileo Galilei (15 February 1564 – 8 January 1642) was a Pisan astronomer, physicist, and engineer recognized as a polymath. Galileo is known as the "Father of Modern Astronomy," the "Father of Modern Physics," the "Father of the Scientific Method," and the "Father of Modern Science." ^[1]

Name

Galilæo ^[2] / Galileo ^{[1] [3] [4]} di Vincenzo Bonaiuti ^[1] Galilæi ^[2] / de' Galiˈlei ^[1] / Galilei ^{[1] [5] [3] [4]} / Galilæi Lynceo ^[2] / Galilei Linceo ^[1]

Galileo Galilei's Signature [1]

Parents

Father: Vincenzo Galilei ^{[1] [3] [5]}

Mother: Giulia Ammannati ^[1]

Birth

Date: 15 February 1564 ^{[1] [3] [4] [5]}

Place: Pisa, Duchy of Florence ^{[1] [3] [4] [5]}

Children

1. Virginia Gamba ^{[1] [5]}
2. Livia Gamba ^{[1] [5]}
3. Vincenzo Gamba ^{[1] [5]}

Death

Date: 8 January 1642 ^{[1] [3] [4] [4] [5]}

Place: Arcetri, Grand Duchy of Tuscany ^{[1] [3] [5]}

Life Story

Birth

Galileo Galiliei was born on 15 February 1564 in Pisa, Duchy of Florence to Vincenzo Galilei and Giulia Ammannati. ^{[1] [3] [4] [5]}

Early Life

When Galileo was eight years old, his family moved to Florence. Muzio Tedaldi, his uncle, was entrusted with his care. When he was ten years old, he moved to Florence and was tutored by Jacopo Borghini. From 1575 to 1578, he was educated at the Vallombrosa Abbey, 30 kilometers south of Florence. ^{[1] [3] [4] [6]}

Education

Galileo considered becoming a priest as a young man, but his father persuaded him to pursue a medical degree at the University of Pisa in 1580. In 1581, he noticed a swinging chandelier and discovered that no matter how far it swung, it took the same amount of time to swing. So far, his father has refused to allow him to study mathematics on purpose, saying that a physician earns more money than a mathematician.

Galileo Galilei by Domenico Tintoretto [1]

However, in 1582-83, Galileo participated in Ostilio Ricci's course, and in the summer of 1583, he invited Ricci to his home, where Ricci tried to persuade Vincenzo to allow his son to continue his mathematical studies. Vincenzo initially fought against it, but eventually gave way. ^{[1] [3] [4] [5] [7]}

Scientific Career

In 1588, Galileo applied for a chair of mathematics at the University of Bologna, but was turned down. His reputation grew, and later that year he was invited to give two lectures to the Florentine Academy, a prestigious literary club, on the layout of the world in Dante's Inferno. He also discovered some theorems on centers of gravity, earning him the respect of mathematicians and the patronage of Guidobaldo del Monte (1545–1607), a nobleman and author of several major books on mechanics. In 1589, he was appointed to the chair of mathematics in Pisa. When his father died in 1591, he was left to handle the financial burden of the family. He came to the University of Padua in 1592, where he taught geometry, mechanics, and astronomy until 1610, which he considered his best years. Galileo made significant discoveries in both pure basic science and practical applied science during this time. Based solely on hazy descriptions of the first workable telescope, which Hans Lippershey attempted to patent in the Netherlands in 1608, Galileo built a telescope with around 3x magnification the following year. Later, he built upgraded versions that could magnify up to 30 times. A Greek mathematician named Giovanni Demisiani coined the term "telescope" for Galileo's equipment at a banquet hosted by Prince Federico Cesi in 1611 to appoint Galileo to his Accademia dei Lincei.

Galileo Galilei by Justus Sustermans [1]

He published his first telescopic astronomical observations in a small essay titled Sidereus Nuncius in March 1610. (Starry Messenger). On November 30, 1609, Galileo pointed his telescope at the Moon. Galileo was the first to identify the cause of the uneven waning as light obstruction from lunar mountains and craters, though he was not the first to examine the Moon through a telescope. On January 7, 1610, Galileo used his telescope to discover "three fixed stars, utterly undetectable due to their smallness," all close to Jupiter and lying on a straight line through it. Observations the next night revealed that the positions of these "stars" in relation to Jupiter were shifting in ways that would have been impossible to explain if they had been fixed stars. On January 10th, Galileo noticed that one of them had vanished, which he attributed to it being hidden behind Jupiter. After only a few days, he realized they were orbiting Jupiter: he had discovered three of Jupiter's four largest moons. He discovered the fourth on January 13th. Galileo named the Medicean stars after his future patron, Cosimo II de' Medici, Grand Duke of Tuscany, and Cosimo's three brothers. Galileo was appointed Grand Duke of Tuscany's mathematician and philosopher. When he visited Rome in 1611, Christopher Clavius' observatory confirmed his findings, and he was greeted as a hero. The Collegio Romano hosted a lavish supper with speakers to commemorate Galileo's astounding discoveries. Galileo was also elected as the sixth member of the Accademia dei Lincei, an honor that meant a lot to him, and he began signing himself 'Galileo Galilei Linceo' from then on. In 1610, Galileo observed Saturn, mistaking its rings for planets and mistaking it for a three-body system. ^{[1] [3] [4] [5] [8] [9] [7]}

For More See Galileo's Scientific Career

Children

Despite being a devout Roman Catholic, Galileo fathered three children out of wedlock with Marina Gamba. Virginia was born in the year 1600, and Livia was born in the year 1601. In addition, they had a son, Vincenzo, who was born in 1606. Galileo concluded that the only life worthy for his daughters was a religious life, so Virginia became Sister Maria Celeste and Livia became Sister Arcangela when they entered the Convent of San Matteo. It is impossible to deny Galileo's frequent visits to the Convent of San Matteo on the outskirts of Florence. After being recognized as Galileo's legal heir, Vincenzo married Sestilia Bocchineri. ^{[1] [3] [5] [9]}

The Assayer

Galileo got into an argument with Father Orazio Grassi, a mathematics professor at the Jesuit Collegio Romano, in 1619. It started as a disagreement about the nature of comets, but by the time Galileo published The Assayer (Il Saggiatore) in 1623, his final volley in the debate, it had grown into a much broader debate about the essence of science itself. ^{[1] [3]}

For More See The Assayer

Controversy over heliocentrism

Galileo defended heliocentrism based on his astronomical observations of 1609. In December 1613, the Grand Duchess Christina of Florence confronted one of Galileo's friends and followers, Benedetto Castelli, with biblical objections to the motion of the Earth. Prompted by this incident, Galileo wrote a letter to Castelli in which he argued that heliocentrism was actually not contrary to biblical texts and that the Bible was an authority on faith and morals, not science. This letter was not published but circulated widely. Two years later, Galileo wrote a letter to Christina that expanded his arguments previously made in eight pages to forty pages. Part of which said:

“I hold that the Sun is located at the centre of the revolutions of the heavenly orbs and does not change place and that the Earth rotates on itself and moves around it. Moreover … I confirm this view not only by refuting Ptolemy’s and Aristotle’s arguments, but also by producing many for the other side, especially some pertaining to physical effects whose causes perhaps cannot be determined in any other way, and other astronomical discoveries; these discoveries clearly confute the Ptolemaic system, and they agree admirably with this other position and confirm it."

By 1615, Galileo's writings on heliocentrism had been submitted to the Roman Inquisition by Father Niccolò Lorini, who claimed that Galileo and his followers were attempting to reinterpret the Bible, which was seen as a violation of the Council of Trent and looked dangerously like Protestantism. At the start of 1616, Monsignor Francesco Ingoli initiated a debate with Galileo, sending him an essay disputing the Copernican system. Galileo later stated that he believed this essay to have been instrumental in the action against Copernicanism that followed. In February 1616, an Inquisitorial commission declared heliocentrism to be "foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture". The Inquisition found that the idea of the Earth's movement "receives the same judgement in philosophy and ... in regard to theological truth it is at least erroneous in faith". On 26 February, Galileo was called to Bellarmine's residence and ordered "to abandon completely ... the opinion that the sun stands still at the centre of the world and the Earth moves, and henceforth not to hold, teach, or defend it in any way whatever, either orally or in writing.” The decree of the Congregation of the Index banned Copernicus's De Revolutionibus and other heliocentric works until correction. He revived his project of writing a book on the subject, encouraged by the election of Cardinal Maffeo Barberini as Pope Urban VIII in 1623. In 1631, Galileo moved to the Villa Il Gioiello to be closer to his daughters. Galileo's book, Dialogue Concerning the Two Chief World Systems, was published in 1632, with formal authorization from the Inquisition and papal permission. Whether unknowingly or deliberately, Simplicio, the defender of the Aristotelian geocentric view in Dialogue Concerning the Two Chief World Systems, was often caught in his own errors and sometimes came across as a fool. ^{[1] [3] [5] [6] [9]}

For More See Controversy Over Heilocentrism

The Galileo Affair

Galileo had alienated one of his biggest and most powerful supporters, the Pope, and was called to Rome to defend his writings in September 1632. He finally arrived in February 1633 and was brought before inquisitor Vincenzo Maculani to be charged. Throughout his trial, Galileo steadfastly maintained that since 1616 he had faithfully kept his promise not to hold any of the condemned opinions, and initially he denied even defending them.

Galileo Facing The Roman Inquisition by Cristiano Banti [1]

In view of Galileo's rather implausible denial that he had ever held Copernican ideas after 1616 or ever intended to defend them in the Dialogue, his final interrogation, in July 1633, concluded with his being threatened with torture if he did not tell the truth, but he maintained his denial despite the threat. The sentence of the Inquisition was delivered on 22 June. It was in three essential parts:

• Galileo was found "vehemently suspect of heresy", namely of having held the opinions that the Sun lies motionless at the centre of the universe, that the Earth is not at its centre and moves, and that one may hold and defend an opinion as probable after it has been declared contrary to Holy Scripture. He was required to "abjure, curse and detest" those opinions.
• He was sentenced to formal imprisonment at the pleasure of the Inquisition. On the following day, this was commuted to house arrest, under which he remained for the rest of his life.
• His offending Dialogue was banned; and in an action not announced at the trial, publication of any of his works was forbidden, including any he might write in the future. ^{[1] [3] [5]}

House Arrest

He appeared once more and was then kept in suspense for months. The Pope eventually decided on life imprisonment. Of the 10 cardinals, three had refused to sign the verdict, Francesco had demanded a pardon and when it was refused he persuaded his brother to make life “imprisonment” that of house arrest in the home of a sympathetic bishop. To pay for this, Galileo was made to kneel and admit to being vain and ambitious and to renounce the Copernican doctrine as being wrong. According to popular legend, after recanting his theory that the Earth moved around the Sun, Galileo allegedly muttered the rebellious phrase "And yet it moves".

Galileo Gazing At The Words "E pur si muove" (Any Yet It Moves) by Murillo [1]

After a period with the friendly Ascanio Piccolomini, the Archbishop of Siena, Galileo was allowed to return to his villa at Arcetri near Florence in 1634, where he spent part of his life under house arrest. At Il Gioiello, Galileo watched the candle burn out of his last days. His daughter Virginia, now Sister Maria Celeste was a great comfort to her father throughout these days. The untimely death of his favourite daughter in 1634, a blow from which Galileo never really recovered came the year after his prosecution in Rome. Alone, depressed, and in constant ill health, he worked to complete his masterpiece, Discourse on the Two New Sciences, which laid the foundations of modern physics. The book was smuggled out of Italy and published in 1636 in the Netherlands. Galileo made his last astronomical discovery in July 1637. Months later, he went completely blind. At last, in 1638, the Roman authorities showed mercy to Galileo. He received permission to move for several months to his house in Florence so that he could more easily visit his doctors. After this brief interlude, he was back at Il Gioiello in September 1638. ^{[1] [3] [5] [9]}

For More See Galileo's House Arrest

Death

Galileo continued to receive visitors until 1642, when, after suffering fever and heart palpitations, he died on 8 January 1642, aged 77. ^{[1] [3] [5]}

Burial

It was indicated he should be buried with his ancestors in the Basilica of Santa Croce in his will and Ferdinando II wanted to erect a mausoleum there in his honour but they face fierce opposition and Galileo was instead buried next to the novices’ chapel, he was reburied in the basilica in 1737. ^[1]

Galileo's Tomb At Santa Croce, Florence [1]

For More See Galileo's Burial

Galileo’s Main Written Works

Galileo's main written works are as follows:

• The Little Balance (1586)
• On Motion (c. 1590)
• Mechanics (c. 1600)
• The Operations of Geometrical and Military Compass (1606)
• The Starry Messenger (1610)
• Discourse on Floating Bodies (1612)
• History and Demonstration Concerning Sunspots (1613)
• "Letter to the Grand Duchess Christina" (1615)
• "Discourse on the Tides" (1616)
• Discourse on the Comets (1619)
• The Assayer (1623)
• Dialogue Concerning the Two Chief World Systems (1632)
• Discourses and Mathematical Demonstrations Relating to Two New Sciences (1638) ^[1]

Legacy

The Inquisition's ban on reprinting Galileo's works was lifted in 1718 In 1741, Pope Benedict XIV authorised the publication of an edition of Galileo's complete scientific works which included a mildly censored version of the Dialogue. In 1758, the general prohibition against works advocating heliocentrism was removed from the Index of prohibited books, although the specific ban on uncensored versions of the Dialogue and Copernicus's De Revolutionibus remained. All traces of official opposition to heliocentrism by the church disappeared in 1835 when these works were finally dropped from the Index. Interest in the Galileo affair was revived in the early 19th century when Protestant polemicists used it to attack Roman Catholicism. Interest in it has waxed and waned ever since. In 1939, Pope Pius XII, in his first speech to the Pontifical Academy of Sciences, within a few months of his election to the papacy, described Galileo as being among the "most audacious heroes of research... not afraid of the stumbling blocks and the risks on the way, nor fearful of the funereal monuments". On 15 February 1990, in a speech delivered at the Sapienza University of Rome, Cardinal Ratzinger (later Pope Benedict XVI) cited some current views on the Galileo affair as forming what he called "a symptomatic case that permits us to see how deep the self-doubt of the modern age, of science and technology, goes today". The Cardinal did not clearly indicate whether he agreed or disagreed with these assertions. He did, however, say: "It would be foolish to construct an impulsive apologetic on the basis of such views.” On 31 October 1992, Pope John Paul II acknowledged that the Church had erred in condemning Galileo for asserting that the Earth revolves around the Sun. In December of the same year, during events to mark the 400th anniversary of Galileo's earliest telescopic observations, Pope Benedict XVI praised his contributions to astronomy. A month later, however, the head of the Pontifical Council for Culture, Gianfranco Ravasi, revealed that the plan to erect a statue of Galileo on the grounds of the Vatican had been suspended. ^{[1] [5]}

For More See Galileo's Legacy

Research Notes

Family Trees

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Translations Needed For Sources

Letter To The Grand Duchess Christina

https://digi.vatlib.it/view/MSS_Vat.lat.8472.pt.1

https://digi.vatlib.it/view/MSS_Vat.lat.8472.pt.2

Sources

1. ↑ ^{1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31 1.32 1.33} Wikipedia Editors. “Galileo Galilei.” Wikipedia. Wikimedia Foundation, (https://en.wikipedia.org/wiki/Galileo_Galilei : 10 June 2021)
2. ↑ ^{2.0 2.1 2.2} “Stamp.Ross.5162.” DigiVatLib. Vatican Libary. (https://digi.vatlib.it/view/STP_Stamp.Ross.5162. : 19 June 2021)
3. ↑ ^{3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16} Van Helden, Albert. “Galileo.” Encyclopædia Britannica. Encyclopædia Britannica, inc. (https://www.britannica.com/biography/Galileo-Galilei : 10 June 2021)
4. ↑ ^{4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9} Boltz, C. L. “Galileo Galilei.” New Scientist. New Scientist, April 7, 1983. (https://www.newscientist.com/people/galileo-galilei/ : 10 June 2021)
5. ↑ ^{5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17} History.com Editors. “Galileo Galilei.” History.com. A&E Television Networks, July 23, 2010. (https://www.history.com/topics/inventions/galileo-galilei : 10 June 2021)
6. ↑ ^{6.0 6.1} Williams, Matt. “Who Was Galileo Galilei?” Universe Today. Universe Today, October 8, 2019. (https://www.universetoday.com/48756/galileo-facts/ : 20 June 2021)
7. ↑ ^{7.0 7.1} O'Connor, J. J., and E. F. Robertson. “Galileo Galilei - Biography.” Maths History. Maths History, 2002. (https://mathshistory.st-andrews.ac.uk/Biographies/Galileo/ : 20 June 2021)
8. ↑ Redd, Nola Taylor. “Galileo Galilei: Biography, Inventions & Other Facts.” Space.com. Space, November 14, 2017. (https://www.space.com/15589-galileo-galilei.html : 20 June 2021)
9. ↑ ^{9.0 9.1 9.2 9.3} Sheehan, William. “Happy 455th Birthday Galileo.” Astronomy.com, February 15, 2019. (https://astronomy.com/news/2019/02/experience-galileos-italy-for-his-455th-birthday : 20 June 2021)

Further Reading

• The Britannica Guide to The 100 Most Influential Scientists (2007), pp. 18, 45, 65-70, 73.
• The Private Life Of Galileo
• Galileo And His Judges
• Memorials Of Galileo