Galileo Galilei

Galileo di Vincenzo Bonaiuti de’ Galilei, also known as Galileo Galilei (/ˌɡaelɪˈleɪoŊ ˌɡælɪˈleɪ/, US also /ˌ̡ælɪˈli\oŊ -/, Italian: [šaliˈlɛ\o ʥalïlɛ\i]), was a Florentine astronomer, physicist, and engineer who was sometimes referred to as a polymath. When he was born, Pisa was a part of the Duchy of Florence. Galileo has been referred to as the founder of modern science, the scientific method, observational astronomy, and classical physics of the modern age.

In addition to studying motion and speed, gravity, free fall, the theory of relativity, inertia, and projectile motion, Galileo also engaged in practical science and technology, defining “hydrostatic balances” and the characteristics of pendulums. He created many military compasses and was among the first Renaissance scientists to create the thermoscope. He constructed a better telescope and used it to study the Milky Way’s stars, Venus’s phases, Jupiter’s four main satellites, Saturn’s rings, lunar craters, and sunspots. He also created the first microscope.

Galileo encountered resistance to Copernican heliocentrism from several scientists as well as from members of the Catholic Church. After looking into the issue in 1615, the Roman Inquisition came to the conclusion that his views went against commonly held readings of the Bible.

Galileo later defended his opinions in Dialogue Concerning the Two Chief World Systems (1632), which seemed to criticize Pope Urban VIII. As a result, the Jesuits, who had previously backed Galileo, and the Pope became enraged. Upon trial by the Inquisition, he was declared “vehemently suspect of heresy” and was made to retract his claims. He was under house arrest for the remainder of his life. He authored Two New Sciences (1638) during this period, mostly on kinematics and material strength.

Childhood and family

Vincenzo Galilei, a lutenist, composer, and music theorist, and Giulia Ammannati, who had tied the knot in 1562, had six children total when Galileo was born on February 15, 1564, in Pisa, which was then a part of the Duchy of Florence. Galileo went on to become a skilled lutenist and probably picked up his father’s distrust of authority at a young age.

Of Galileo’s five siblings, three lived to childhood. As a lutenist and composer, the youngest, Michelangelo (or Michelagnolo), further increased Galileo’s financial difficulties for the remainder of his life. Unable to give their brothers-in-law their just portion of the dowries promised by their father, Michelangelo prevented them from pursuing legal action to recover unpaid dowries. Additionally, Michelangelo periodically needed to borrow money from Galileo to sustain his musical endeavors and travels. These monetary difficulties could have influenced Galileo’s early drive to create innovations that would increase his revenue.

Galileo Galilei’s family relocated to Florence when he was eight years old, but he spent the next two years under Muzio Tedaldi’s care. After leaving Pisa at the age of eleven to live with his family in Florence, Jacopo Borghini tutored Galileo while he was there. He had his education in the Vallombrosa Abbey, some 30 kilometers southeast of Florence, from 1575 to 1578, specializing in logic.

Name

Galileo was inclined to address himself just by his given name. His initial name shared the same etymology as his occasionally used family name, Galilei, and surnames were optional at the time in Italy. His ancestor Galileo Bonaiuti, a significant physician, professor, and statesman in Florence during the 15th century, is eventually the source of both his given name and his family name. About two centuries later, Galileo Galilei was buried at Florence’s Basilica of Santa Croce, the same church where Galileo Bonaiuti had been interred.

When he did use more than one name, it was occasionally Galileo Galilei Linceo, referring to his membership in the Accademia dei Lincei, an esteemed Italian scientific society. Tuscan families tended to name their firstborn son after their parents’ surname around the middle of the sixteenth century. Therefore, it is not necessary that Galileo Galilei was named after his ancestor Galileo Bonaiuti. The Latin “Galilaeus,” which means “of Galilee,” is the source of the Italian male given name “Galileo” (and consequently the surname “Galilei”).

A well-known joke would be made about Galileo’s name and surname’s biblical origins. One of Galileo’s adversaries, the Dominican priest Tommaso Caccini, gave a contentious and significant sermon in 1614 during the Galileo controversy. Acts 1:11, “Ye men of Galilee, why stand ye gazing up into heaven?” was one of the passages Jesus specifically quoted.

Children

Galileo was a very devout Catholic, yet he and Marina Gamba had three unmarried children together. Vincenzo (born 1606) was their son, and they had two daughters, Virginia (born 1600) and Livia (born 1601).

Galileo thought the daughters were unmarried due to their illegal origin, if not because they would have required unreasonably high dowries or maintenance, which would have been comparable to Galileo’s past severe financial difficulties with two of his sisters. The life of a religious was their only worthwhile alternative. The San Matteo convent in Arcetri took both girls in and they lived there for the remainder of their lives.

When Virginia joined the convent, she was given the name Maria Celeste. She passed away on April 2, 1634, and is buried at Florence’s Basilica of Santa Croce alongside Galileo. Livia was sick for the majority of her life and adopted the name Sister Arcangela. Later, Vincenzo married Sestilia Bocchineri after being recognized as Galileo’s legitimate successor.

Career and First Contributions to Science

Galileo was encouraged by his father to pursue a medical degree at the University of Pisa in 1580, despite having given the priesthood considerable thought throughout his formative years. Francesco Buonamici and Girolamo Borro’s lectures at Florence had an impact on him. While studying medicine in 1581, he caught sight of a hanging chandelier that was being affected by air currents, causing it to swing in ever smaller arcs. No matter how far it swung, it appeared to him that the chandelier took the same amount of time to swing back and forth in relation to his heartbeat.

Upon his return home, he assembled two equal-length pendulums and discovered that they maintained time in unison when he swung one with a broad sweep and the other with a tiny sweep. Nearly a century later, Christiaan Huygens’ work was the first to employ the tautochrone property of a swinging pendulum to produce an accurate watch. Galileo had up to now been purposefully kept out of mathematics because a doctor made more money than a mathematician. But after inadvertently attending a geometry lecture, he persuaded his reticent father to allow him to pursue a degree in mathematics and natural philosophy rather than medicine.

In addition to inventing the thermoscope, which was the precursor of the thermometer, he wrote a little book in 1586 detailing the construction of an original hydrostatic balance, which first attracted the interest of academics. In 1588, Galileo was appointed as an instructor at the Accademia delle Arti del Disegno in Florence, where he taught perspective and chiaroscuro.

Galileo also studied disegno, a word that encompasses fine art. In an effort to put out a rigorous cosmological model of Dante’s hell, he gave two lectures on the shape, location, and size of Dante’s inferno the same year at the Florentine Academy’s request. Galileo developed an aesthetic mindset as a result of being influenced by the city’s creative heritage and the creations of Renaissance artists.

He had a lasting connection with the Florentine painter Cigoli when he was a young teacher at the Accademia.

He was assigned to the Pisa mathematics chair in 1589. After his father passed away in 1591, his younger brother Michelagnolo was sent to take care of him. He went to the University of Padua in 1592, where he worked as a geometry, mechanics, and astronomy professor until 1610. Galileo produced important discoveries during this time in both practical applied science (such as strength of materials and developing the telescope) and pure basic science (such as astronomy and kinematics of motion). Among his many interests was the study of astrology, which at the time was associated with astronomy and mathematics.

Astronomy

Kepler’s supernova

The supernova of 1572 had been seen by Tycho Brahe and others. Galileo first learned of the supernova of 1572 and the less brilliant nova of 1601 through Ottavio Brenzoni’s letter dated January 15, 1605, which was sent to him. In 1604, Galileo noted Kepler’s Supernova and talked about it. Galileo came to the conclusion that these new stars were distant stars because they showed no discernible diurnal parallax, which refuted the Aristotelian theory that the skies are unchangeable.

Telescope with Refractive Index

Galileo created a telescope with a magnification of nearly three times the first operational telescope the next year, based solely on hazy descriptions of the device that Hans Lippershey attempted to patent in the Netherlands in 1608. Later on, he created enhanced versions that could magnify up to thirty times.

An observer could view enlarged, upright representations of the Earth using a Galilean telescope, sometimes called a terrestrial telescope or spyglass. He could also use it to watch the sky, as he was once among those capable of building telescopes that were suitable for such a function. He gave legislators in Venice a demonstration of one of his early telescopes, which had a magnification of around 8 or 9. This was on August 25, 1609.

Galileo made money off of his telescopes as a side business, selling them to traders who might use them for commerce and as a means of navigation. In March 1610, he published his first telescopic observations of the sky in a little dissertation called Sidereus Nuncius (Starry Messenger).

Moon

Galileo pointed his telescope to the Moon on November 30, 1609. Galileo was the first to identify the source of the uneven fading as a light blockage from lunar mountains and craters, even though English mathematician Thomas Harriot had done so four months earlier and had merely seen a “strange spottednesse” when looking at the Moon via a telescope. He also created topographical maps in his studies, calculating the mountain tops. The Moon was not the translucent, flawless sphere that Aristotle said it was, nor was it even the first “planet,” as proposed by Dante, an “eternal pearl to magnificently ascend into the heavenly empyrian.”

Although Thomas Harriot or William Gilbert may have discovered the lunar libration in latitude earlier, Galileo is commonly given credit for making the discovery in 1632.

Painter Cigoli, a friend of Galileo’s, painted a lifelike picture of the Moon; nevertheless, it is likely that he used his personal telescope to make the view.

The moons of Jupiter

Using a telescope, Galileo saw what he first reported to be “three fixed stars, totally invisible by their smallness” on January 7, 1610; these stars were all near Jupiter and formed a straight line that passed through the planet. Subsequent nightly observations revealed that these “stars” were shifting in a way that would have been puzzling if they were fixed stars in relation to Jupiter. One of them had vanished, as reported by Galileo on January 10. He explained this finding by saying that it was concealed by Jupiter. After a few days, he deduced that they were in Jupiter’s orbit as he had found three of the planet’s four biggest moons. On January 13, he made the fourth discovery.

In honor of his future patron, Cosimo II de’ Medici, Grand Duke of Tuscany, and Cosimo’s three brothers, Galileo dubbed the group of four stars the Medicean stars. Nevertheless, they were later dubbed Galilean satellites after their discoverer. Simon Marius independently discovered these satellites on January 8, 1610; he named them Io, Europa, Ganymede, and Callisto, which were published in his 1614 Mundus Iovialis.

Galileo’s discoveries of Jupiter’s satellites sparked debate in astronomy because, contrary to Aristotelian cosmology, which maintained that all celestial bodies should orbit the Earth, a planet with smaller planets orbiting it could not exist. At first, many astronomers and philosophers did not think Galileo could have found such a planet.

This issue was made worse by the fact that other astronomers could not independently verify Galileo’s findings. The guests in Bologna had trouble seeing the moons when he showed them how to use the telescope. Martin Horky, one of them, noticed that while looking through a telescope, some fixed stars, including Spica Virginis, appeared twice. This, he interpreted as proof that the device was misleading in its observation of the sky, raising doubts about the moon’s actual existence.

When Galileo visited the observatory the next year, Christopher Clavius in Rome welcomed him as a hero despite not knowing how to analyze the findings. Over the course of the following eighteen months, Galileo kept observing the satellites, and by the middle of 1611, he had managed to determine the periods of each one with an astonishing degree of accuracy, something Johannes Kepler had thought unattainable.

Galileo recognized a use for his discoveries in science. Clocks on ships at sea have to be synced with those at the prime meridian to determine the vessels’ east-west location. Safe sailing depended heavily on the answer to this longitude problem, for which Spain and subsequently Holland awarded significant awards. Galileo applied for the awards because the eclipses of the moons he found might be used to set naval clocks because they were reasonably regular and their timings could be anticipated with high precision. Although it was too challenging to see the moons from a ship, the technique was used to land surveys, such as the remapping of France.

Venus’s phases

Galileo noted in September 1610 that Venus displays a complete cycle of phases resembling those of the moon. Since Venus’s illuminated hemisphere faces Earth when it is on the opposite side of the Sun and away from the Earth when it is on the Earth side of the Sun, the heliocentric model of the Solar System, developed by Nicolaus Copernicus, predicted that all phases would be visible. In Ptolemy’s geocentric model, none of the planets’ orbits could cross the Sun’s spherical shell. Venus’s orbit was traditionally totally on the near side of the Sun, where it could only display fresh and crescent phases.

It might also be fully located on the far side of the Sun, where it could only display gibbous and complete phases. Galileo’s telescopic observations of Venus’s crescent, gibbous, and full phases revealed flaws in the Ptolemaic paradigm. Due to his findings, most astronomers in the early 17th century adopted one of the several geo-heliocentric planetary models, including the Tychonic, Capellan, and Extended Capellan models, which can include an Earth that rotates once a day or not. All of these provided an explanation for Venus’s phases without “disputing” the star parallax forecast of complete heliocentrism.

Thus, Galileo’s most empirically significant and practical contribution to the two-stage process of moving from complete geocentrism to full heliocentrism via geo-heliocentrism was his discovery of Venus’ phases.

Neptune and Saturn

Galileo saw Saturn in 1610 as well, although at first, he thought it was a three-body system and confused its rings for planets. Later, when he looked at the planet, he believed that two of the bodies had vanished since Saturn’s rings were facing Earth. He was even more perplexed when, in 1616, he saw the planet and the rings emerged again.

Neptune was first seen by Galileo in 1612. It is listed in his journals among a plethora of ordinary faint stars. Though he saw its motion in relation to the stars before losing sight of it, he was unaware that it was a planet.

Sunspots

Galileo observed sunspots with both the unaided eye and a telescope. The permanent perfection of the heavens, as proposed by traditional Aristotelian celestial physics, presented additional challenge in light of their existence. A strong case was also made against Tycho Brahe’s geoheliocentric system and the Ptolemaic system by Francesco Sizzi and others in 1612–1613, based on an apparent yearly change in their paths.

Galileo and the Jesuit Christoph Scheiner got into a protracted and acrimonious argument over who was first to identify and interpret sunspots. Mark Welser stood in the center; it was to him that Scheiner had revealed his finding and he asked Galileo for his thoughts. They were both ignorant of the fact that sunspots had previously been observed and documented by Johannes Fabricius.

Stars and the Milky Way

Galileo saw the Milky Way, which was once thought to be hazy, and discovered that it was actually a vast cluster of stars that seemed like clouds from Earth. He found several additional stars that are too far away to be seen with the unaided eye. In 1617, he had a sighting of the twin star Mizar in Ursa Major.

Galileo said in the Starry Messenger that stars seemed to be only fireballs, almost unchanged by the telescope, and that they were unlike planets, which the telescope showed to be disks. However, not long after, he wrote in his Letters on Sunspots that the telescope had shown the planets and stars to be “quite round”. From that moment on, he kept on reporting that stars could be seen via telescopes to be spherical and to have a diameter of a few seconds of arc. In addition, he came up with a way to calculate a star’s apparent size without using a telescope.

His approach was to suspend a thin rope in his line of sight to the star and determine the greatest distance from which it would completely conceal the star, as outlined in his Dialogue Concerning the Two Chief World Systems. He could determine the angle of the star at his viewing position subtended by measuring this distance and the diameter of the rope.

He said in his Dialogue that he had discovered that a star of first magnitude may have an apparent diameter of little more than 5 arcseconds, while a star of sixth magnitude could have an apparent diameter of almost 5/6 arcseconds. Galileo, like the majority of astronomers in his day, was unaware that the apparent diameters of the stars he measured were artificial, the result of atmospheric distortion and diffraction, and did not correspond to the actual sizes of the stars.

Galileo was able to refute anti-Copernican claims, such as Tycho’s, that these stars would have to be extraordinarily massive in order for their annual parallaxes to be undetectable, though, because his values were significantly smaller than earlier estimates of the apparent sizes of the brightest stars, such as those made by Brahe.

Similar measurements of stars were done by other astronomers, including Simon Marius, Giovanni Battista Riccioli, and Martinus Hortensius. Marius and Riccioli came to the conclusion that the decreased diameters were insufficient to refute Tycho’s reasoning.

Tide Theory

In 1615, Cardinal Bellarmine said that “a true physical demonstration that the sun does not circle the earth but the earth circles the sun” was necessary in order to support the Copernican theory. Galileo believed that his theory of the tides offered this kind of proof. He originally wanted to title his Dialogue Concerning the Two Chief World Systems the Dialogue on the Ebb and Flow of the Sea because he believed this idea to be so essential. The Inquisition ordered the removal of the reference to tides from the title.

According to Galileo, the Earth’s rotation on its axis and revolution around the Sun cause water in the oceans to slosh back and forth, causing a spot on its surface to speed up and slow down. This phenomenon is known as the tides. In 1616, he sent Cardinal Orsini his first report on the tides, which went viral. His idea, which accurately accounted for the insignificant tides midway around the Adriatic Sea compared to those at the ends, provided the first insight into the significance of ocean basin shapes in the magnitude and timing of tides. But as a comprehensive explanation for the origin of tides, his proposal fell flat.

One high tide every day would exist if this idea were accurate. The fact that Venice experiences two daily high tides rather than just one, spaced around 12 hours apart, was a problem that Galileo and his contemporaries were aware of. Galileo disregarded this oddity, blaming it on a number of secondary explanations, such as the sea’s depth and form. Later, Albert Einstein said that Galileo’s “fascinating arguments” were constructed out of a yearning for tangible evidence of Earth’s motion, which led him to accept them without question.

Along with rejecting Kepler’s elliptical planet orbits, Galileo also disregarded the notion that the Moon was the source of the tides, which had been recognized since antiquity and by Kepler’s contemporary Johannes Kepler.

Galileo persisted in promoting his idea of tides, viewing it as the last indication of Earth’s motion.

Francesco Porcia’s picture of Galileo Galilei

Galileo and Father Orazio Grassi, a math professor at the Jesuit Collegio Romano, got into a disagreement in 1619. The issue started out as one about the nature of comets, but by the time Galileo wrote The Assayer (Il Saggiatore) in 1623—his last blow in the conflict—it had expanded to include a far larger debate about the nature of science in general. Galileo is described as a philosopher and the Grand Duke of Tuscany’s “Matematico Primario” on the book’s title page.

The Assayer has been called Galileo’s scientific manifesto since it is so full of his beliefs about how science ought to be conducted. An Astronomical Disputation on the Three Comets of the Year 1618, a treatise written by Father Grassi under a pseudonym had been released early in 1619 and covered the characteristics of a comet that had surfaced late in November of the previous year. Grassi came to the conclusion that the comet was a blazing mass that had traveled a fixed distance from Earth over a portion of a huge circle, and since it moved more slowly through the sky than the Moon, it had to be farther away.

Discourse on Comets, a later paper mostly authored by Galileo himself but published under the pseudonym of one of his students, Florentine lawyer Mario Guiducci, criticized Grassi’s reasoning and conclusions. Although they presented some speculative hypotheses that are now known to be incorrect, Galileo and Guiducci did not provide a definite theory of their own on the nature of comets. (Tycho Brahe had at the time suggested the proper method for studying comets.) The Jesuit Christoph Scheiner was gratuitously attacked in the first section of Galileo and Guiducci’s Discourse, and the work was replete with disparaging statements against the Collegio Romano teachers.

Offended, Grassi quickly responded with a polemical tract of his own, The Astronomical and Philosophical Balance, claiming to be one of his own students and writing under the pseudonym Lothario Sarsio Sigensano.

Galileo’s devastating response to the Astronomical Balance was the Assayer. It is regarded by many as a masterwork of polemical writing, whereby “Sarsi’s” arguments are met with utter contempt. Widespread praise was given to it, and Urban VIII, the newly appointed pope, was especially happy. Ten years earlier, in Rome, Barberini—the future Urban VIII—had taken a stand in favor of Galileo and the Lincean Academy.

Many Jesuits were irrevocably enraged by Galileo’s disagreement with Grassi, and Galileo and his allies believed that they were to blame for his eventual conviction, even if there is inconclusive evidence to support this belief.

Debate over heliocentrism

The majority of educated people at the time of Galileo’s dispute with the Church held either Tycho Brahe’s new theory, which combined heliocentrism with geocentrism, or the Aristotelian geocentric view, which holds that the Earth is the center of the universe and the orbit of all heavenly bodies. Religious and scientific issues were joined in opposition to heliocentrism and Galileo’s works on the subject. Bible verses that suggested the Earth’s fixed character gave rise to religious resistance to heliocentrism. Brahe presented scientific resistance, claiming that if heliocentrism were real, there should have been an annual star parallax at the time. However, there wasn’t. Because the stars were so far away, Aristarchus and Copernicus had correctly hypothesized that parallax was insignificant.

Tycho retorted that if stars were so far away and their apparent size was due to their actual size, they would be far larger than the Sun since they appear to have quantifiable angular dimensions. In actuality, without the use of contemporary telescopes, it is impossible to discern the actual size of faraway stars.

On the basis of his 1609 astronomical observations, Galileo advocated heliocentrism. Benedetto Castelli, a friend and supporter of Galileo, was addressed by the Grand Duchess Christina of Florence in December 1613 with scriptural challenges to Earth’s motion. This encounter prompted Galileo to write a letter to Castelli in which he contended that the Bible was the ultimate source of religion and morality, not science, and that heliocentrism was in fact not at odds with biblical passages. Despite not being published, this letter was extensively shared. Two years later, in a forty-page letter to Christina, Galileo extended his earlier eight-page arguments.

Father Niccolò Lorini said that Galileo and his supporters were trying to reinterpret the Bible, which was considered as a breach of the Council of Trent and looked alarmingly like Protestantism. By 1615, Galileo’s publications on heliocentrism had been turned over to the Roman Inquisition. Lorini quoted from Galileo’s letter to Castelli in particular. Galileo traveled to Rome to stand out for his beliefs. Francesco Ingoli sparked a discussion with Galileo at the beginning of 1616 by sending him an article that disputed the Copernican theory. Galileo subsequently declared that he thought the subsequent movement against Copernicanism was largely due to this article.

It is possible that the Inquisition hired Ingoli to publish an expert opinion piece on the dispute, which served as the foundation for the Inquisition’s activities. Eighteen mathematical and physical arguments against heliocentrism were the main topic of the article. It mostly used ideas from Tycho Brahe, most notably that the stars were necessary for heliocentrism since they seemed to be considerably bigger than the Sun. Four religious considerations were also presented in the text, but Ingoli advised Galileo to concentrate on the mathematical and scientific arguments rather than the biblical concepts.

Heliocentrism was labeled “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture” by an Inquisitorial committee in February 1616. The concept of Earth’s movement, according to the Inquisition, “receives the same judgment in philosophy and… regarding theological truth, it is at least erroneous in faith”. Cardinal Bellarmine was given instructions by Pope Paul V to inform Galileo of this discovery and to tell him to give up heliocentrism.

“To abandon completely… the opinion that the sun stands still at the center of the world and the Earth moves, and henceforth not to hold, teach, or defend it in any way whatsoever, either orally or in writing,” was the directive given to Galileo when he was summoned to Bellarmine’s home on February 26. Copernicus’s De Revolutionibus and other heliocentric books were outlawed by the Congregation of the Index edict until they were corrected.

Galileo avoided the debate completely for the following ten years. Encouraged by the election of Cardinal Maffeo Barberini as Pope Urban VIII in 1623, he picked up his book project again. Galileo’s friend and admirer Barberini had disapproved of Galileo’s rebuke in 1616. Galileo’s ensuing work, Dialogue Concerning the Two Chief World Systems, was approved by the Pope and the Inquisition before being published in 1632.

Prior to this, Galileo was specifically instructed by Pope Urban VIII to include arguments both in favor of and against heliocentrism in the book, being cautious not to support heliocentrism. Simplicio, the advocate of the Aristotelian geocentric perspective in Dialogue Concerning the Two Chief World Systems, was frequently caught in his own mistakes and occasionally came out as a fool, whether on purpose or not. In fact, even though Galileo claims in the book’s introduction that the figure is named after a well-known Aristotelian philosopher (called “Simplicio” in Italian, “Simplicius” in Latin), the Italian word “Simplicio” also carries the meaning “simpleton.”

Dialogue Concerning the Two Chief World Systems came across as an advocacy work that defended Copernican theory and attacked Aristotelian geocentrism because of the way Simplicio was portrayed.

The majority of historians concur that Galileo was taken aback by the reception of his work and did not behave maliciously. The Pope, however, did not take the Copernican advocacy or the alleged mockery from the people lightly.

In September 1632, Galileo was summoned to Rome to defend his works after alienating the Pope, one of his strongest and most influential supporters. When he did arrive in February 1633, inquisitor Vincenzo Maculani took him before him to lay charges. Galileo firmly insisted at his trial that he had scrupulously adhered to his vow not to hold any of the condemned ideas since 1616, and at first, he denied even offering a defense for them. Eventually, though, he was convinced to acknowledge that his Dialogue could have given the reader the idea that it was meant to be a defense of Copernicanism, even if it was not his genuine goal.

Galileo’s final interrogation in July 1633 ended with a threat of torture if he did not tell the truth, which was somewhat implausible given his denial that he had ever held Copernican ideas after 1616 or intended to defend them in the Dialogue. Galileo refused to change his denial despite the threat.

On June 22, the Inquisition’s sentence was given. There were three main components to it:

• The accusations against Galileo included holding the views that the Earth moves and is not at the center of the universe, that the Sun lies motionless at the center of the universe, and that one may hold and defend an opinion as probable after it has been declared contrary to Holy Scripture. Galileo was found to be “vehemently suspect of heresy” (though he was never formally charged with heresy, sparing him from corporal punishment). “Abjure, curse, and detest” was the proper response to those viewpoints.
• He received a formal jail term, renewable at the Inquisition’s discretion. This was changed to house arrest the next day, where he spent the remainder of his life.
• In addition to the prohibition on his objectionable dialogue, publishing of all of his works—including any he could create in the future—was prohibited—a move that was not disclosed during the trial.

Galileo is said to have murmured the disobedient words “And yet it moves” after abandoning his belief that the Earth revolves around the Sun. There was a report that a picture from the 1640s, by the Spanish painter Bartolomé Esteban Murillo or an artist from his school, showed an imprisoned Galileo seemingly staring at the words “E pur si muove” engraved on the wall of his jail. The words remained covered until restoration work was done in 1911. A century after his passing, the legend’s first documented story was published. Stillman Drake stated that “there is no doubt now that the famous words were already attributed to Galileo before his death” in reference to the picture.

Nevertheless, astrophysicist Mario Livio’s thorough examination has shown that the artwork in question is most likely a replica of a work painted by the Flemish painter Roman-Eugene Van Maldeghem in 1837.

Galileo spent some time living under house arrest in 1634 after being granted permission to return to his property in Arcetri, close to Florence, following his time with the kind Archbishop of Siena, Ascanio Piccolomini. For the following three years, Galileo was required to read the Seven Penitential Psalms once a week. But his daughter Maria Celeste took over the responsibility, relieving him of it after obtaining church authorization to do so.

Two New Sciences, one of Galileo’s best works, was the product of his labors during his house detention. In order to get around the censor, he summarized his work on the two sciences—kinematics and material strength—that he had conducted some forty years earlier and published in Holland. Albert Einstein greatly commended this work. Galileo is frequently referred to be the “father of modern physics” as a result of his contributions. In 1638, he became totally blind, suffered from a severe hernia, and experienced sleeplessness. As a result, he was allowed to go to Florence for medical guidance.

According to Dava Sobel, Pope Urban VIII had grown concerned with political intrigue and court intrigue before Galileo’s trial and subsequent judgment for heresy in 1633. He also started to dread persecution or threats to his own life. In this regard, Sobel contends that insiders and Galileo’s adversaries brought the issue of Galileo before the pope. Out of fear and rage at being accused of being weak in the church’s defense, Urban retaliated against Galileo. Galileo and his findings are situated in contemporary scientific and societal situations by Mario Livio. Specifically, he contends that scientific denial is the antithesis of the Galileo controversy.

Death

Galileo, who was 77 years old when he passed away on January 8, 1642, from a fever and heart palpitations, continued to receive visitors. Ferdinando II, the Grand Duke of Tuscany, intended to build a marble monument in his honor and bury him close to his father’s and his predecessors’ tombs in the main body of the Basilica of Santa Croce.

But these plans were abandoned in response to protests from Cardinal Francesco Barberini and Pope Urban VIII, who denounced Galileo for “vehement suspicion of heresy” inside the Catholic Church. Rather, he was laid to rest in a little chamber beside the novices’ chapel at the end of a hallway leading from the basilica’s southern transept to the sacristy. Following the construction of a monument in his honor, he was reburied in the basilica’s main body in 1737; however, during this process, three fingers and a tooth were taken from his bones. The Museo Galileo in Florence, Italy, is presently hosting an exhibition featuring one of these fingers.

Contributions from Science

This and other facts, not few in number or less worth knowing, I have succeeded in proving; and what I consider more important, there have been opened up to this vast and most excellent science, of which my work is merely the beginning, ways and means by which other minds more acute than mine will explore its remote corners.

— Galileo Galilei, Two New Sciences

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