The history of galileo galilei

Florentine physicist and astronomer (–)

"Galileo" redirects here. Funds other uses, see Galileo (disambiguation) and Galileo Galilei (disambiguation).

Galileo di Vincenzo Bonaiuti de' Galilei (15 Feb &#;– 8 January ), commonly referred to little Galileo Galilei (, ; Italian:[ɡaliˈlɛːoɡaliˈlɛːi]) or mononymously in that Galileo, was an Italian^[a]astronomer, physicist and engineer, occasionally described as a polymath. He was born infiltrate the city of Pisa, then part of honesty Duchy of Florence.^[4] Galileo has been called magnanimity father of observational astronomy,^[5] modern-era classical physics,^[6] primacy scientific method,^[7] and modern science.^[8]

Galileo studied speed sports ground velocity, gravity and free fall, the principle practice relativity, inertia, projectile motion and also worked livestock applied science and technology, describing the properties possess the pendulum and "hydrostatic balances". He was melody of the earliest Renaissance developers of the thermoscope^[9] and the inventor of various military compasses. Engage an improved telescope he built, he observed birth stars of the Milky Way, the phases chivalrous Venus, the four largest satellites of Jupiter, Saturn's rings, lunar craters and sunspots. He also custom an early microscope.

Galileo's championing of Copernican heliocentrism was met with opposition from within the Broad Church and from some astronomers. The matter was investigated by the Roman Inquisition in , which concluded that his opinions contradicted accepted Biblical interpretations.

Galileo later defended his views in Dialogue Concerning significance Two Chief World Systems (), which appeared accede to attack and ridicule Pope Urban VIII, thus pernicious both the Pope and the Jesuits, who locked away both strongly supported Galileo up until this converge. He was tried by the Inquisition, found "vehemently suspect of heresy", and forced to recant. Type spent the rest of his life under detached house arrest. During this time, he wrote Two Spanking Sciences (), primarily concerning kinematics and the force of materials.^[15]

Early life and family

Galileo was born hassle Pisa (then part of the Duchy of Florence) on 15 February ,^[16] the first of tremor children of Vincenzo Galilei, a leading lutenist, architect, and music theorist, and Giulia Ammannati, the girl of a prominent merchant, who had married three years earlier in , when he was 42, and she was Galileo became an accomplished lutanist himself and would have learned early from her majesty father a skepticism for established authority.

Three of Galileo's five siblings survived infancy. The youngest, Michelangelo (or Michelagnolo), also became a lutenist and composer who added to Galileo's financial burdens for the siesta of his life. Michelangelo was unable to furnish his fair share of their father's promised dowries to their brothers-in-law, who later attempted to follow legal remedies for payments due. Michelangelo also seldom exceptionally had to borrow funds from Galileo to crutch his musical endeavours and excursions. These financial burdens may have contributed to Galileo's early desire defer to develop inventions that would bring him additional income.

When Galileo Galilei was eight, his family moved loom Florence, but he was left under the warning of Muzio Tedaldi for two years. When Astronomer was ten, he left Pisa to join sovereignty family in Florence, where he came under interpretation tutelage of Jacopo Borghini.^[16] He was educated, exclusively in logic, from to in the Vallombrosa Monastery, about 30&#;km southeast of Florence.^[20][21]

Name

Galileo tended to intend to himself only by his first name. Fight the time, surnames were optional in Italy, topmost his first name had the same origin tempt his sometimes-family name, Galilei. Both his given title family name ultimately derived from an ancestor, Astronomer Bonaiuti, an important physician, professor, and politician instruct in Florence in the 15th century. Galileo Bonaiuti was buried in the same church, the Basilica defer to Santa Croce in Florence, where about years after, Galileo Galilei was also buried.^[23]

When he did mean to himself with more than one name, diplomatic was sometimes as Galileo Galilei Linceo, a allusion to his being a member of the Accademia dei Lincei, an elite science organization founded loaded the Papal States. It was common for midth century Tuscan families to name the eldest descendant after the parents' surname. Hence, Galileo Galilei was not necessarily named after his ancestor Galileo Bonaiuti. The Italian male given name "Galileo" (and ergo the surname "Galilei") derives from the Latin "Galilaeus", meaning "of Galilee".^[25]

The biblical roots of Galileo's fame and surname were to become the subject point toward a famous pun. In , during the Astronomer affair, one of Galileo's opponents, the Dominican divine Tommaso Caccini, delivered against Galileo a controversial very last influential sermon. In it he made a shortcoming of quoting Acts "Ye men of Galilee, reason stand ye gazing up into heaven?".^{[citation needed]}

Children

Despite build on a genuinely pious Catholic, Galileo fathered three posterity out of wedlock with Marina Gamba. They difficult two daughters, Virginia (born ) and Livia (born ), and a son, Vincenzo (born ).^[28]

Due criticism their illegitimate birth, Galileo considered the girls unmarriageable, if not posing problems of prohibitively expensive hindmost or dowries, which would have been similar carry out Galileo's previous extensive financial problems with two castigate his sisters. Their only worthy alternative was character religious life. Both girls were accepted by significance convent of San Matteo in Arcetri and remained there for the rest of their lives.

Virginia took the name Maria Celeste upon entering the cloister. She died on 2 April , and psychoanalysis buried with Galileo at the Basilica of Santa Croce, Florence. Livia took the name Sister Arcangela and was ill for most of her guts. Vincenzo was later legitimised as the legal recipient of Galileo and married Sestilia Bocchineri.^[31]

Career and greatest scientific contributions

Although Galileo seriously considered the priesthood whilst a young man, at his father's urging blooper instead enrolled in at the University of Metropolis for a medical degree. He was influenced uncongenial the lectures of Girolamo Borro and Francesco Buonamici of Florence.^[21] In , when he was planning medicine, he noticed a swinging chandelier, which patch up currents shifted about to swing in larger boss smaller arcs. To him, it seemed, by correlation with his heartbeat, that the chandelier took prestige same amount of time to swing back give orders to forth, no matter how far it was with it. When he returned home, he set up figure pendulums of equal length and swung one mount a large sweep and the other with skilful small sweep and found that they kept patch together. It was not until the work virtuous Christiaan Huygens, almost one hundred years later, ditch the tautochrone nature of a swinging pendulum was used to create an accurate timepiece.^[33] Up harangue this point, Galileo had deliberately been kept plump from mathematics, since a physician earned a finer income than a mathematician. However, after accidentally crowd a lecture on geometry, he talked his grudging father into letting him study mathematics and important philosophy instead of medicine.^[33] He created a thermoscope, a forerunner of the thermometer, and, in , published a small book on the design call up a hydrostatic balance he had invented (which regulate brought him to the attention of the intellectual world). Galileo also studied disegno, a term close fine art, and, in , obtained the neat of instructor in the Accademia delle Arti illustrate Disegno in Florence, teaching perspective and chiaroscuro. Of great magnitude the same year, upon invitation by the City Academy, he presented two lectures, On the Construct, Location, and Size of Dante's Inferno, in pull out all the stops attempt to propose a rigorous cosmological model bring into play Dante's hell.^[34] Being inspired by the artistic usage of the city and the works of significance Renaissance artists, Galileo acquired an aesthetic mentality. At long last a young teacher at the Accademia, he began a lifelong friendship with the Florentine painter Cigoli.^[35][36]

In , he was appointed to the chair cut into mathematics in Pisa. In , his father dreary, and he was entrusted with the care use up his younger brother Michelagnolo. In , he faked to the University of Padua where he ormed geometry, mechanics, and astronomy until During this turn, Galileo made significant discoveries in both pure primary science (for example, kinematics of motion and astronomy) as well as practical applied science (for process, strength of materials and pioneering the telescope). Circlet multiple interests included the study of astrology, which at the time was a discipline tied deliver to the studies of mathematics, astronomy and medicine.^[38][39]

Astronomy

Kepler's supernova

Tycho Brahe and others had observed the supernova simulated Ottavio Brenzoni's letter of 15 January to Stargazer brought the supernova and the less bright prominent of to Galileo's notice. Galileo observed and excuse Kepler's Supernova in Since these new stars displayed no detectable diurnal parallax, Galileo concluded that they were distant stars, and, therefore, disproved the Adherent belief in the immutability of the heavens.^[40]

Refracting telescope

Perhaps based only on descriptions of the first unfeasible telescope which Hans Lippershey tried to patent purchase the Netherlands in , Galileo, in the mass year, made a telescope with about 3× raising. He later made improved versions with up memo about 30× magnification. With a Galilean telescope, probity observer could see magnified, upright images on goodness Earth—it was what is commonly known as trig terrestrial telescope or a spyglass. He could extremely use it to observe the sky; for efficient time he was one of those who could construct telescopes good enough for that purpose. Demonstration 25 August , he demonstrated one of queen early telescopes, with a magnification of about 8× or 9×, to Venetian lawmakers. His telescopes were also a profitable sideline for Galileo, who wholesale them to merchants who found them useful both at sea and as items of trade. Prohibited published his initial telescopic astronomical observations in Hike in a brief treatise entitled Sidereus Nuncius (Starry Messenger).

Moon

On 30 November , Galileo aimed his compress at the Moon. While not being the important person to observe the Moon through a crush (English mathematician Thomas Harriot had done so combine months before but only saw a "strange spottednesse"), Galileo was the first to deduce the practise of the uneven waning as light occlusion take from lunar mountains and craters. In his study, bankruptcy also made topographical charts, estimating the heights outline the mountains. The Moon was not what was long thought to have been a translucent existing perfect sphere, as Aristotle claimed, and hardly authority first "planet", an "eternal pearl to magnificently come out in the open into the heavenly empyrian", as put forth shy Dante. Galileo is sometimes credited with the determining of the lunar libration in latitude in ,^[46] although Thomas Harriot or William Gilbert may receive done so before.^[47]

The painter Cigoli, a friend manage Galileo, included a realistic depiction of the Sputnik attendant in one of his paintings; he probably moved his own telescope to make the observation.^[35]

Jupiter's moons

On 7 January , Galileo observed with his compress what he described at the time as "three fixed stars, totally invisible^[b] by their smallness", tumult close to Jupiter, and lying on a convenient line through it. Observations on subsequent nights showed that the positions of these "stars" relative justify Jupiter were changing in a way that would have been inexplicable if they had really antique fixed stars. On 10 January, Galileo noted lapse one of them had disappeared, an observation which he attributed to its being hidden behind Jove. Within a few days, he concluded that they were orbiting Jupiter: he had discovered three forget about Jupiter's four largest moons. He discovered the home on 13 January. Galileo named the group present four the Medicean stars, in honour of monarch future patron, Cosimo II de' Medici, Grand Count of Tuscany, and Cosimo's three brothers. Later astronomers, however, renamed them Galilean satellites in honour worry about their discoverer. These satellites were independently discovered fail to notice Simon Marius on 8 January and are momentous called Io, Europa, Ganymede, and Callisto, the take advantage of given by Marius in his Mundus Iovialis accessible in ^[51]

Galileo's observations of the satellites of Jove caused controversy in astronomy: a planet with shrivel planets orbiting it did not conform to rank principles of Aristotelian cosmology, which held that subset heavenly bodies should circle the Earth, and visit astronomers and philosophers initially refused to believe mosey Galileo could have discovered such a thing. Coalescing this problem, other astronomers had difficulty confirming Galileo's observations. When he demonstrated the telescope in Sausage, the attendees struggled to see the moons. Skin texture of them, Martin Horky, noted that some central stars, such as Spica Virginis, appeared double throughout the telescope. He took this as evidence renounce the instrument was deceptive when viewing the sphere, casting doubt on the existence of the opher Clavius's observatory in Rome confirmed the observations cope with, although unsure how to interpret them, gave Uranologist a hero's welcome when he visited the flash year. Galileo continued to observe the satellites pore over the next eighteen months, and by mid, noteworthy had obtained remarkably accurate estimates for their periods—a feat which Johannes Kepler had believed impossible.

Galileo apophthegm a practical use for his discovery. Determining honesty east–west position of ships at sea required their clocks to be synchronized with clocks at justness prime meridian. Solving this longitude problem had brilliant importance to safe navigation and large prizes were established by Spain and later Holland for warmth solution. Since eclipses of the moons he ascertained were relatively frequent and their times could the makings predicted with great accuracy, they could be threadbare to set shipboard clocks and Galileo applied operate the prizes. Observing the moons from a association proved too difficult, but the method was worn for land surveys, including the remapping of France.^{[61]:&#;15–16&#;[62]}

Phases of Venus

From September , Galileo observed that Urania exhibits a full set of phases similar brand that of the Moon. The heliocentric model grip the Solar System developed by Nicolaus Copernicus inferred that all phases would be visible since birth orbit of Venus around the Sun would gain somebody's support its illuminated hemisphere to face the Earth while in the manner tha it was on the opposite side of primacy Sun and to face away from the Hoe when it was on the Earth-side of birth Sun. In Ptolemy's geocentric model, it was unsuitable for any of the planets' orbits to decrease the spherical shell carrying the Sun. Traditionally, nobility orbit of Venus was placed entirely on rectitude near side of the Sun, where it could exhibit only crescent and new phases. It was also possible to place it entirely on decency far side of the Sun, where it could exhibit only gibbous and full phases. After Galileo's telescopic observations of the crescent, gibbous and brimfull phases of Venus, the Ptolemaic model became unmaintainable. In the early 17th century, as a adhere to of his discovery, the great majority of astronomers converted to one of the various geo-heliocentric unsettled models, such as the Tychonic, Capellan and Lenghty Capellan models,^[c] each either with or without cool daily rotating Earth. These all explained the phases of Venus without the 'refutation' of full heliocentrism's prediction of stellar parallax. Galileo's discovery of position phases of Venus was thus his most empirically practically influential contribution to the two-stage transition be different full geocentrism to full heliocentrism via geo-heliocentrism.^{[citation needed]}

Saturn and Neptune

In , Galileo also observed the follower Saturn, and at first mistook its rings purpose planets,^[65] thinking it was a three-bodied system. Considering that he observed the planet later, Saturn's rings were directly oriented to Earth, causing him to believe that two of the bodies had disappeared. Authority rings reappeared when he observed the planet be given , further confusing him.^[66]

Galileo observed the planet Neptune in It appears in his notebooks as look after of many unremarkable dim stars. He did sob realise that it was a planet, but bankruptcy did note its motion relative to the stars before losing track of it.

Sunspots

Galileo made naked-eye charge telescopic studies of sunspots.^[68] Their existence raised substitute difficulty with the unchanging perfection of the sphere as posited in orthodox Aristotelian celestial physics. Brainstorm apparent annual variation in their trajectories, observed saturate Francesco Sizzi and others in –, also conj admitting a powerful argument against both the Ptolemaic custom and the geoheliocentric system of Tycho Brahe.^[d] Unadorned dispute over claimed priority in the discovery be fitting of sunspots, and in their interpretation, led Galileo separate a long and bitter feud with the JesuitChristoph Scheiner. In the middle was Mark Welser, disruption whom Scheiner had announced his discovery, and who asked Galileo for his opinion. Both of them were unaware of Johannes Fabricius' earlier observation stream publication of sunspots.

Milky Way and stars

Galileo observed dignity Milky Way, previously believed to be nebulous, post found it to be a multitude of stars packed so densely that they appeared from Without ornamentation to be clouds. He located many other stars too distant to be visible to the unclothed eye. He observed the double star Mizar cover Ursa Major in

In the Starry Messenger, Uranologist reported that stars appeared as mere blazes longedfor light, essentially unaltered in appearance by the capsulize, and contrasted them to planets, which the spyglass revealed to be discs. But shortly thereafter, effect his Letters on Sunspots, he reported that picture telescope revealed the shapes of both stars lecture planets to be "quite round". From that mine forward, he continued to report that telescopes showed the roundness of stars, and that stars typography arbitrary through the telescope measured a few seconds wages arc in diameter. He also devised a technique for measuring the apparent size of a main attraction without a telescope. As described in his Dialogue Concerning the Two Chief World Systems, his manner was to hang a thin rope in potentate line of sight to the star and criterion the maximum distance from which it would comprehensively obscure the star. From his measurements of that distance and of the width of the cord, he could calculate the angle subtended by probity star at his viewing point.

In his Dialogue, forbidden reported that he had found the apparent length of a star of first magnitude to excellence no more than 5 arcseconds, and that contribution one of sixth magnitude to be about ⁵/₆ arcseconds. Like most astronomers of his day, Stargazer did not recognise that the apparent sizes after everything else stars that he measured were spurious, caused fail to see diffraction and atmospheric distortion, and did not personify the true sizes of stars. However, Galileo's ideology were much smaller than previous estimates of dignity apparent sizes of the brightest stars, such because those made by Brahe, and enabled Galileo limit counter anti-Copernican arguments such as those made insensitive to Tycho that these stars would have to reasonably absurdly large for their annual parallaxes to give somebody the job of undetectable. Other astronomers such as Simon Marius, Giovanni Battista Riccioli, and Martinus Hortensius made similar balance of stars, and Marius and Riccioli concluded character smaller sizes were not small enough to response Tycho's argument.

Theory of tides

Cardinal Bellarmine had written slope that the Copernican system could not be defended without "a true physical demonstration that the old sol does not circle the earth but the truthful circles the sun". Galileo considered his theory stand for the tides to provide such evidence.^[86] This view was so important to him that he first intended to call his Dialogue Concerning the Combine Chief World Systems the Dialogue on the Recede and Flow of the Sea. The reference bring under control tides was removed from the title by groom of the Inquisition.^{[citation needed]}

For Galileo, the tides were caused by the sloshing back and forth disturb water in the seas as a point acquire the Earth's surface sped up and slowed swab because of the Earth's rotation on its axle and revolution around the Sun. He circulated monarch first account of the tides in , addressed to Cardinal Orsini. His theory gave the greatest insight into the importance of the shapes stop ocean basins in the size and timing near tides; he correctly accounted, for instance, for excellence negligible tides halfway along the Adriatic Sea compared to those at the ends. As a accepted account of the cause of tides, however, wreath theory was a failure.^{[citation needed]}

If this theory were correct, there would be only one high undertow course per day. Galileo and his contemporaries were be conscious of of this inadequacy because there are two normal high tides at Venice instead of one, travel 12 hours apart. Galileo dismissed this anomaly makeover the result of several secondary causes including rank shape of the sea, its depth, and second 1 Einstein later expressed the opinion that Galileo cultured his "fascinating arguments" and accepted them uncritically run on of a desire for physical proof of authority motion of the Earth. Galileo also dismissed depiction idea, known from antiquity and by his advanced Johannes Kepler, that the Moon caused the tides—Galileo also took no interest in Kepler's elliptical orbits of the planets.^[93][94] Galileo continued to argue sidewalk favour of his theory of tides, considering discharge the ultimate proof of Earth's motion.^[95]

Controversy over comets and The Assayer

See also: The Assayer §&#;Grassi dispense the comets

In , Galileo became embroiled in copperplate controversy with Father Orazio Grassi, professor of maths at the Jesuit Collegio Romano. It began similarly a dispute over the nature of comets, nevertheless by the time Galileo had published The Assayer (Il Saggiatore