Galileo Galilei

Galileo Galilei
Justus Sustermans - Portrait of Galileo Galilei, 1636.jpg
Portrait of Galileo Galilei (1636), by Justus Sustermans
Born15 February 1564
Died8 January 1642(1642-01-08) (aged 77)
ResidenceGrand Duchy of Tuscany
Alma materUniversity of Pisa 1580–1585 (no degree)
Known for
Scientific career
FieldsAstronomy, physics, engineering, natural philosophy, mathematics
Academic advisorsOstilio Ricci[1]
Notable students
Galileo Galilei Signature 2.svg
His father was the musician Vincenzo Galilei. Galileo Galilei's mistress Marina Gamba (1570 – 21 August 1612?) bore him two daughters (Maria Celeste (Virginia, 1600–1634) and Livia (1601–1659), both of whom became nuns), and a son, Vincenzo (1606–1649), a lutenist.

Galileo Galilei (/ AY-oh, also US: / EE-oh, Italian: [ɡaliˈlɛːo ɡaliˈlɛi]; 15 February 1564[3] – 8 January 1642) was an astronomer, physicist and engineer, sometimes described as a polymath from Pisa.[4] Galileo has been called the "father of observational astronomy",[5] the "father of modern physics",[6][7] the "father of the scientific method",[8] and the "father of modern science".[9][10]

Galileo studied speed and velocity, gravity and free fall, the principle of relativity, inertia, projectile motion and also worked in applied science and technology, describing the properties of pendulums and "hydrostatic balances", inventing the thermoscope and various military compasses, and using the telescope for scientific observations of celestial objects. His contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the observation of the four largest satellites of Jupiter, the observation of Saturn's rings, and the analysis of sunspots.

Galileo's championing of heliocentrism and Copernicanism was controversial during his lifetime, when most subscribed to geocentric models such as the Tychonic system.[11] He met with opposition from astronomers, who doubted heliocentrism because of the absence of an observed stellar parallax.[11] The matter was investigated by the Roman Inquisition in 1615, which concluded that heliocentrism was "foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture".[11][12][13] Galileo later defended his views in Dialogue Concerning the Two Chief World Systems (1632), which appeared to attack Pope Urban VIII and thus alienated him and the Jesuits, who had both supported Galileo up until this point.[11] He was tried by the Inquisition, found "vehemently suspect of heresy", and forced to recant. He spent the rest of his life under house arrest.[14][15] While under house arrest, he wrote Two New Sciences, in which he summarized work he had done some forty years earlier on the two sciences now called kinematics and strength of materials.[16][17]

Early life and family

Galileo was born in Pisa (then part of the Duchy of Florence), Italy, on 15 February 1564,[18] the first of six children of Vincenzo Galilei, a famous lutenist, composer, and music theorist, and Giulia (née Ammannati), who had married in 1562. Galileo became an accomplished lutenist himself and would have learned early from his father a scepticism for established authority,[19] the value of well-measured or quantified experimentation, an appreciation for a periodic or musical measure of time or rhythm, as well as the results expected from a combination of mathematics and experiment.

Three of Galileo's five siblings survived infancy. The youngest, Michelangelo (or Michelagnolo), also became a noted lutenist and composer although he contributed to financial burdens during Galileo's young adulthood. Michelangelo was unable to contribute his fair share of their father's promised dowries to their brothers-in-law, who would later attempt to seek legal remedies for payments due. Michelangelo would also occasionally have to borrow funds from Galileo to support his musical endeavours and excursions. These financial burdens may have contributed to Galileo's early desire to develop inventions that would bring him additional income.

When Galileo Galilei was eight, his family moved to Florence, but he was left with Jacopo Borghini for two years. He was educated from 1575 to 1578 in the Vallombrosa Abbey, about 30 km southeast of Florence.[20]


The surname Galilei derives from the given name of an ancestor, Galileo Bonaiuti, a physician, university teacher and politician who lived in Florence from 1370 to 1450; his descendants had changed their family name from Bonaiuti (or Buonaiuti) to Galilei in his honor in the late 14th century.[21] Galileo Bonaiuti was buried in the same church, the Basilica of Santa Croce in Florence, where about 200 years later his more famous descendant Galileo Galilei was also buried.[22]

It was common for mid-sixteenth-century Tuscan families to name the eldest son after the parents' surname.[23] Hence, Galileo Galilei was not necessarily named after his ancestor Galileo Bonaiuti. The Italian male given name "Galileo" (and thence the surname "Galilei") derives from the Latin "Galilæus", meaning "of Galilee", a biblically significant region in Northern Israel.[24][25] Because of that region, the adjective galilaios (Greek γαλιλαίος, Latin Galilæus, Italian galileo), which means "Galilean", has been used in antiquity (particularly by emperor Julian) to refer to Christ and his followers;[26] after this, the adjective has been adopted as a name with a meaning similar to Jesus or Christian.[citation needed]

The biblical roots of Galileo's name and surname were to become the subject of a famous pun.[27] In 1614, during the Galileo affair, one of Galileo's opponents, the Dominican priest Tommaso Caccini, delivered against Galileo a controversial and influential sermon. In it he made a point of quoting 1:11, "Ye men of Galilee, why stand ye gazing up into heaven?".[28]


Galileo's beloved elder daughter, Virginia (Sister Maria Celeste), was particularly devoted to her father. She is buried with him in his tomb in the Basilica of Santa Croce, Florence.

Despite being a genuinely pious Roman Catholic,[29] Galileo fathered three children out of wedlock with Marina Gamba. They had two daughters, Virginia (born in 1600) and Livia (born in 1601), and a son, Vincenzo (born in 1606).[30]

Because of their illegitimate birth, their father considered the girls unmarriageable, if not posing problems of prohibitively expensive support or dowries, which would have been similar to Galileo's previous extensive financial problems with two of his sisters.[31] Their only worthy alternative was the religious life. Both girls were accepted by the convent of San Matteo in Arcetri and remained there for the rest of their lives.[32] Virginia took the name Maria Celeste upon entering the convent. She died on 2 April 1634, and is buried with Galileo at the Basilica of Santa Croce, Florence. Livia took the name Sister Arcangela and was ill for most of her life. Vincenzo was later legitimised as the legal heir of Galileo and married Sestilia Bocchineri.[33]

Other Languages
Afrikaans: Galileo Galilei
Alemannisch: Galileo Galilei
አማርኛ: ጋሊልዮ
aragonés: Galileo Galilei
armãneashti: Galileo Galilei
asturianu: Galileo Galilei
Avañe'ẽ: Galiléo Galiléi
Aymar aru: Galileo Galilei
azərbaycanca: Qalileo Qaliley
Bân-lâm-gú: Galileo Galilei
башҡортса: Галилео Галилей
беларуская: Галілеа Галілей
беларуская (тарашкевіца)‎: Галілео Галілей
Bikol Central: Galileo Galilei
български: Галилео Галилей
Boarisch: Galileo Galilei
bosanski: Galileo Galilei
brezhoneg: Galileo Galilei
čeština: Galileo Galilei
Chavacano de Zamboanga: Galileo Galilei
dolnoserbski: Galileo Galilei
español: Galileo Galilei
Esperanto: Galilejo
estremeñu: Galileo Galilei
Fiji Hindi: Galileo Galilei
Gàidhlig: Galileo Galilei
贛語: 伽利略
hornjoserbsce: Galileo Galilei
hrvatski: Galileo Galilei
Bahasa Hulontalo: Galileo Galilei
Bahasa Indonesia: Galileo Galilei
interlingua: Galileo Galilei
Interlingue: Galileo Galilei
íslenska: Galileo Galilei
italiano: Galileo Galilei
Kabɩyɛ: Galilée
Kapampangan: Galileo Galilei
Kinyarwanda: Galileo Galilei
Kiswahili: Galileo Galilei
Kreyòl ayisyen: Galileo Galilei
latviešu: Galileo Galilejs
Lëtzebuergesch: Galileo Galilei
lietuvių: Galilėjus
Limburgs: Galileo Galilei
Lingua Franca Nova: Galileo Galilei
Livvinkarjala: Galileo Galilei
la .lojban.: galileos.galileis
lumbaart: Galileo Galilei
македонски: Галилео Галилеј
Malagasy: Galileo Galilei
მარგალური: გალილეო გალილეი
Bahasa Melayu: Galileo Galilei
Minangkabau: Galileo Galilei
Mìng-dĕ̤ng-ngṳ̄: Galileo Galilei
Mirandés: Galileu Galilei
မြန်မာဘာသာ: ဂယ်လီလီယို
Nāhuatl: Galileo Galilei
Nederlands: Galileo Galilei
Napulitano: Galileo Galilei
Nordfriisk: Galileo Galilei
Norfuk / Pitkern: Galileo Galilei
norsk nynorsk: Galileo Galilei
ଓଡ଼ିଆ: ଗାଲିଲିଓ
oʻzbekcha/ўзбекча: Galileo Galilei
Piemontèis: Galileo Galilei
Plattdüütsch: Galileo Galilei
polski: Galileusz
português: Galileu Galilei
Qaraqalpaqsha: Galileo Galilei
română: Galileo Galilei
Runa Simi: Galileo Galilei
русиньскый: Ґалілео Ґалілей
sicilianu: Galileu Galilei
Simple English: Galileo Galilei
slovenčina: Galileo Galilei
slovenščina: Galileo Galilei
српски / srpski: Галилео Галилеј
srpskohrvatski / српскохрватски: Galileo Galilei
Taqbaylit: Galileo Galilei
татарча/tatarça: Галилео Галилей
Türkçe: Galileo Galilei
українська: Галілео Галілей
ئۇيغۇرچە / Uyghurche: گالىلېي
vepsän kel’: Galilei Galileo
Tiếng Việt: Galileo Galilei
Volapük: Galileo Galilei
文言: 伽利略
Yorùbá: Galileo Galilei
粵語: 伽利略
žemaitėška: Galėlies Galėliejos