Galileo GalileiGalileo Galilei

Or:Or:

How a telescope can get you How a telescope can get you into troubleinto trouble

This logo denotes A102 appropriate

In Context:In Context:

► These changes, Copernicus through Galileo, all These changes, Copernicus through Galileo, all occurred during the Renaissanceoccurred during the Renaissance

► Roots in the 13Roots in the 13thth century Florence with Dante century Florence with Dante (The Inferno) and Petrarch (humanist (The Inferno) and Petrarch (humanist philosophy)philosophy)

► Composers 15Composers 15thth century Ockeghem and 16 century Ockeghem and 16thth century Gesualdocentury Gesualdo

► Artists Bruegel the Elder, Raphael, and Artists Bruegel the Elder, Raphael, and MichelangeloMichelangelo

► And And thethe Renaissance man, Leonardo da Vinci Renaissance man, Leonardo da Vinci

CompareCompare

Bayeux Tapestry 11Bayeux Tapestry 11thth C C Pieter Breugel 16Pieter Breugel 16thth C C

CompareCompare

Regina Celi (plainchant)Regina Celi (plainchant) Stabat Mater (motet)Stabat Mater (motet)

RebirthRebirth

► A rediscovery (and reinterpretation) of A rediscovery (and reinterpretation) of classical Greek and Roman timesclassical Greek and Roman times

► A time of religious turmoil and growing A time of religious turmoil and growing humanismhumanism

► Rise of merchant class, challenges to feudal Rise of merchant class, challenges to feudal system, urbanization, political change, roots system, urbanization, political change, roots of modern countriesof modern countries

► Time of discovery, global expansion of Time of discovery, global expansion of Western powersWestern powers

► Copernicus, Brahe, Kepler all products of Copernicus, Brahe, Kepler all products of this rebirththis rebirth

Another Field of DiscoveryAnother Field of Discovery

Into this Melee comes GalileoInto this Melee comes Galileo

► B. 1564 in Pisa, son of B. 1564 in Pisa, son of famous musician,famous musician, Florentine CamerataFlorentine Camerata

► 1581 Enrolls in the 1581 Enrolls in the University of PisaUniversity of Pisa First in medicine, then First in medicine, then

switches to mathematicsswitches to mathematics

► Takes a teaching post at Takes a teaching post at Pisa in 1589Pisa in 1589

► Moves to Padua to accept Moves to Padua to accept position of Professor of position of Professor of Mathematics in 1592Mathematics in 1592

Even though a Devout Even though a Devout Catholic…Catholic…

► Galileo fathered three Galileo fathered three children out of wedlock children out of wedlock with Maria Gambawith Maria Gamba

► The girls are forced to join The girls are forced to join a nunnerya nunnery Livia lives a quiet nun’s lifeLivia lives a quiet nun’s life Vincenzio legitimized, Vincenzio legitimized,

becomes government workerbecomes government worker

► Virginia becomes Maria Virginia becomes Maria Celeste, remains close to Celeste, remains close to her father and her father and corresponds often (120 corresponds often (120 letters!)letters!)

► Most Illustrious Lord Father,Most Illustrious Lord Father,

I cannot rest any longer without news, both for the infinite love I bear you, and I cannot rest any longer without news, both for the infinite love I bear you, and also for fear lest the sudden cold, which in general disagrees so much with you, also for fear lest the sudden cold, which in general disagrees so much with you, should have caused a return of your usual pains and other complaints. I should have caused a return of your usual pains and other complaints. I therefore send the man who takes this letter purposely to hear how you are, therefore send the man who takes this letter purposely to hear how you are, and also when you expect to set out on your journey[and also when you expect to set out on your journey[1] I have been extremely ] I have been extremely busy at the dinner-napkins…busy at the dinner-napkins…

As I have no cell of my own to sleep in, Sister Diamanta kindly allows me to As I have no cell of my own to sleep in, Sister Diamanta kindly allows me to share hers, depriving herself of the company of her own sister for my sake. But share hers, depriving herself of the company of her own sister for my sake. But the room is so bitterly cold that with my head so infected, I do not know how I the room is so bitterly cold that with my head so infected, I do not know how I shall remain well, unless you can help me by lending me a set of those white shall remain well, unless you can help me by lending me a set of those white bed-hangings which you will not want now. I would be glad to know if you can bed-hangings which you will not want now. I would be glad to know if you can do me this service. Moreover, I beg you to be so kind as to send me that book of do me this service. Moreover, I beg you to be so kind as to send me that book of yours which has just been published, [yours which has just been published, [3] so that I may read it, for I have a great ] so that I may read it, for I have a great desire to see it. desire to see it.

These few cakes I send are some I made a few days ago, intending to give them These few cakes I send are some I made a few days ago, intending to give them to you when you came to bid us adieu. As you departure is not so near as we to you when you came to bid us adieu. As you departure is not so near as we feared, I send them lest they should get dry. Sister Arcangela is still under feared, I send them lest they should get dry. Sister Arcangela is still under medical treatment, and is much tried by the remedies. I am not well myself*, medical treatment, and is much tried by the remedies. I am not well myself*, but being so accustomed to ill health, I do not make much of it, seeing, too, that but being so accustomed to ill health, I do not make much of it, seeing, too, that it is the Lord's will to send me continually some such little trial as this…it is the Lord's will to send me continually some such little trial as this…

* She will die at age 34

Early StudiesEarly Studies

► He finds the period He finds the period motion of a pendulum motion of a pendulum fascinatingfascinating

► Times each swing of the Times each swing of the chandelier with his pulsechandelier with his pulse

► Periodic motion is Periodic motion is fundamental in fundamental in understanding gravity understanding gravity planetary motionplanetary motion Tower of Pisa story Tower of Pisa story

apocryphalapocryphal

► ExperimentalistExperimentalist

GravityGravity► Calculates the acceleration Calculates the acceleration

of gravity by rolling of gravity by rolling spheres down a rampspheres down a ramp

► Investigates the trajectory Investigates the trajectory of projectilesof projectiles In 1537 Italian scientist In 1537 Italian scientist

Tartaglia said that the Tartaglia said that the trajectory of a bullet was trajectory of a bullet was really a continuous curvereally a continuous curve

► Says objects fall with the Says objects fall with the same acceleration, same acceleration, regardless of weight, regardless of weight, contradicting Aristotlecontradicting Aristotle If two objects are attached, If two objects are attached,

do they fall faster?do they fall faster?

Motion from GravityMotion from Gravity

► After 1 second an After 1 second an object rolls some object rolls some distance xdistance x

► After 2 seconds the After 2 seconds the object has rolled 4xobject has rolled 4x

► After 3 seconds…After 3 seconds… Irrespective of weight!Irrespective of weight!

► Whereas for Aristotle Whereas for Aristotle rest was the natural rest was the natural state and motion state and motion required an “agent”, required an “agent”, for Galileo motion was for Galileo motion was the natural state and a the natural state and a changechange in motion, in motion, acceleration, required acceleration, required an “agent”an “agent”

NASA Proves it!NASA Proves it!

The MediciThe Medici

►Hugely powerful Florentine family from Hugely powerful Florentine family from 1313thth to 17 to 17thth century century

►Family produced three popes and Family produced three popes and many city-state rulersmany city-state rulers

►Ran the most respected bank in EuropeRan the most respected bank in Europe►1605: Galileo serves as tutor to the 1605: Galileo serves as tutor to the

Cosimo de MediciCosimo de Medici►1609: Cosimo II becomes Grand Duke 1609: Cosimo II becomes Grand Duke

of Tuscanyof Tuscany

16091609

► Galileo obtains a Galileo obtains a telescope from telescope from Flemish opticiansFlemish opticians Invented by Hans Invented by Hans

Lippershey in 1608Lippershey in 1608 Galileo improves Galileo improves

upon itupon it► Always practical, Always practical,

Galileo tries to sell it Galileo tries to sell it to merchantsto merchants Affords a two hour Affords a two hour

advanced warning of advanced warning of incoming shipsincoming ships

Always curious:Always curious:

► Galileo points his Galileo points his telescope skywardtelescope skyward

► Sees ten times further Sees ten times further than any man beforethan any man before

► Traditional cosmology Traditional cosmology called into serious called into serious questionquestion

► Sees the Moon is not Sees the Moon is not perfect but covered perfect but covered with mountains and with mountains and valleysvalleys

Recently discovered sketches of the Recently discovered sketches of the MoonMoon

A place just like any other place: A place just like any other place: heretical!heretical!

HeresyHeresy

► Sees the Moons of Sees the Moons of Jupiter in orbitJupiter in orbit Proof that all things Proof that all things

don’t orbit the Sundon’t orbit the Sun

►Names the Names the moons after the moons after the Medici heirsMedici heirs ““a confirmation of a confirmation of

the Medici’s destiny, the Medici’s destiny, almost a scientific almost a scientific proof of their proof of their dynastic horoscope”dynastic horoscope”

ImperfectionImperfection

► Sees that the Sun is Sees that the Sun is covered with spotscovered with spots Not the perfect Sun Not the perfect Sun

professed by the professed by the ChurchChurch

► Moving sunspots Moving sunspots shows that the Sun shows that the Sun rotatesrotates

Damning EvidenceDamning Evidence

► Sees that Venus has phases just like the MoonSees that Venus has phases just like the Moon► Explainable only if Venus orbits the SunExplainable only if Venus orbits the Sun

16101610

► Resigned post at Resigned post at PaduaPadua

► Took position of Took position of "Chief Mathematician "Chief Mathematician and Philosopher" to and Philosopher" to Grand Duke Cosimo IIGrand Duke Cosimo II

► Published Sidereus Published Sidereus Nuncius [Starry Nuncius [Starry Messenger], Messenger], dedicated to Cosimo IIdedicated to Cosimo II

Word gets outWord gets out

►Sir Henry Wotton, the British Sir Henry Wotton, the British Ambassador to Venice, Ambassador to Venice, reports:reports: "strangest piece of news that "strangest piece of news that

hath ever yet received from any hath ever yet received from any part of the world . . . these part of the world . . . these discoveries will certainly discoveries will certainly overturn all astronomy and overturn all astronomy and astrology… [Galileo] runneth a astrology… [Galileo] runneth a fortune to be either exceedingly fortune to be either exceedingly famous or exceedingly famous or exceedingly ridiculous."ridiculous."

Kepler to Galileo in 1610Kepler to Galileo in 1610► “Your observations concerning the sparkling

appearance of the fixed stars, in contrast with the circular appearance of the planets, what other conclusions shall we draw from these differences, Galileo, than that the fixed stars generate their light from within, while the planets being oblique, are illuminated from without; that is to use Bruno's terms, "the former are suns, the latter are, moons or earths?" Nevertheless, let him not mislead us onto his belief in the infinite worlds, as numerous as the fixed stars and all similar to our own…”

► . . . I rejoice that I am to some extent restored to life by your work. If you had discovered any planets revolving around one of the fixed stars, there would be awaiting for me chains and prison amid Bruno's innumerabilities, I should rather say, exile to his infinite space . . .

DisbeliefDisbelief

► Devout people would view these Devout people would view these phenomena through Galileo’s telescope and phenomena through Galileo’s telescope and not believe what they were seeingnot believe what they were seeing But they But they wouldwould believe it when they looked at believe it when they looked at

ships at sea!ships at sea!► New instruments for Copernicanism raise New instruments for Copernicanism raise

questions:questions: Does the telescope help, or hinder our vision? Does the telescope help, or hinder our vision? Does it extend, or merely distort our senses? Does it extend, or merely distort our senses? Aren't our eyes adequate to see all we are Aren't our eyes adequate to see all we are

entitled to see? entitled to see? Why would the natural world include things we Why would the natural world include things we

can't see with our unaided eyes? can't see with our unaided eyes?

16151615

► Galileo writes a lengthy Galileo writes a lengthy letter to the Grand letter to the Grand Duchess Christina, Duchess Christina, Cosimo II’s motherCosimo II’s mother

► He expressed concern He expressed concern that theologians, that theologians, ignorant of basic ignorant of basic astronomical principles, astronomical principles, risked erring through risked erring through misinterpretation of misinterpretation of scripture and scripture and misapplication of its misapplication of its authority to problems in authority to problems in natural philosophy natural philosophy

ReactionReaction

►1614: A Dominican friar, Niccolò Lorini, 1614: A Dominican friar, Niccolò Lorini, sends a copy of Galileo's letter to sends a copy of Galileo's letter to Rome as evidence of his heresyRome as evidence of his heresy Copernican theory is condemned by the Copernican theory is condemned by the

ChurchChurch►1616: Galileo is called to Rome by 1616: Galileo is called to Rome by

Cardinal *Bellarmine and told to stop Cardinal *Bellarmine and told to stop teaching the Copernican systemteaching the Copernican system Galileo thinks that there is no heresy Galileo thinks that there is no heresy ifif

you read his theories just the right way you read his theories just the right way *remember him?

A prideful man, Galileo tries to A prideful man, Galileo tries to counter ecumenicism with logiccounter ecumenicism with logic

►Joshua 10:12-14Joshua 10:12-14: Then spake Joshua to : Then spake Joshua to the Lord in the day when the Lord the Lord in the day when the Lord delivered up to the Amorites before the delivered up to the Amorites before the children of Israel, and he said in the sight children of Israel, and he said in the sight of Israel, Sun, stand thou still upon of Israel, Sun, stand thou still upon Gideon; and thou, Moon, in the valley of Gideon; and thou, Moon, in the valley of Ajalon. And the sun stood still, and the Ajalon. And the sun stood still, and the moon stayed, until the people had moon stayed, until the people had avenged themselves upon their enemies.avenged themselves upon their enemies.

According to GalileoAccording to Galileo

► [I]t is obvious that if the sun should cease its [I]t is obvious that if the sun should cease its own proper motion, the day would become own proper motion, the day would become shorter, and not longer.... shorter, and not longer....

► The way to lengthen the day would be to The way to lengthen the day would be to speed up the sun's proper motion; and to speed up the sun's proper motion; and to cause the sun to remain above the horizon cause the sun to remain above the horizon for some time in one place* ... it would be for some time in one place* ... it would be necessary to [accelerate] the customary necessary to [accelerate] the customary speed of the sun about three hundred sixty speed of the sun about three hundred sixty times.... times....

*Like going backwards on a moving sidewalk at the airport

Digging himself deeperDigging himself deeper

►[Theologians] are forced to interpret the [Theologians] are forced to interpret the words in the midst of the heavens a little words in the midst of the heavens a little knottily, saying that this means no more knottily, saying that this means no more than that the sun stood still while it than that the sun stood still while it was ... above our horizon. [U]nless I am was ... above our horizon. [U]nless I am mistaken we may avoid this and all other mistaken we may avoid this and all other knots if, in agreement with the knots if, in agreement with the Copernican system, we place the sun in Copernican system, we place the sun in the "midst" -- that is, in the center -- of the "midst" -- that is, in the center -- of the celestial orbs of planetary the celestial orbs of planetary rotations....rotations....

But a Chance to Dig Himself But a Chance to Dig Himself OutOut

► 1623: Galileo's friend, Cardinal 1623: Galileo's friend, Cardinal Maffeo Barberini, became Pope Maffeo Barberini, became Pope Urban VIIIUrban VIII

► The two had had long talks about The two had had long talks about Copernicanism before Barberini’s Copernicanism before Barberini’s ascendancyascendancy

► 1625: Galileo began writing a 1625: Galileo began writing a defense of Copernican theory, defense of Copernican theory, later to be known as later to be known as Dialogue Dialogue Concerning the Two Chief World Concerning the Two Chief World SystemsSystems First it was a treatise on the tidesFirst it was a treatise on the tides

► Not a gravitational theory!Not a gravitational theory!► Tides happen because the oceans slosh Tides happen because the oceans slosh

due the Earth’s motion (proof!)due the Earth’s motion (proof!)

CharactersCharacters

► Salvati AKA CopernicusSalvati AKA Copernicus► Simplicio AKA PtolemySimplicio AKA Ptolemy

Simplicius was Aristotle Simplicius was Aristotle translatortranslator

► Sagredo, a scholar who Sagredo, a scholar who asks questions of the asks questions of the twotwo

► Simplicio responds with Simplicio responds with Ptolemaic (and stupid) Ptolemaic (and stupid) answersanswers

► Salvati gives the wise Salvati gives the wise answersanswers

Guess Who is Who?Guess Who is Who?

► Galileo puts the words of his friend Barberini Galileo puts the words of his friend Barberini in Simplicio’s mouthin Simplicio’s mouth May have been an attempt at humorMay have been an attempt at humor

► The Pope was The Pope was NOTNOT amused! amused!

Simplicio

Salvati

The InquisitionThe Inquisition

► 1632: Galileo ordered to Rome to stand trial for 1632: Galileo ordered to Rome to stand trial for heresyheresy Remember what happened to Bruno 32 years earlier?Remember what happened to Bruno 32 years earlier?

► Only his previous friendship with Barberini and Only his previous friendship with Barberini and letters of mercy from his daughter saved Galileoletters of mercy from his daughter saved Galileo

► The Medici disown himThe Medici disown him

Verdict: GuiltyVerdict: Guilty

► Forced to recant his Forced to recant his beliefsbeliefs

► Reported to have Reported to have whispered as he whispered as he was led away, “But was led away, “But [the Earth] still [the Earth] still moves.”moves.”

► Sentenced to house Sentenced to house arrest for his last arrest for his last ten yearsten years

Final YearsFinal Years

► 1631: Buys the villa "Il Goiello" in Arcetri, near 1631: Buys the villa "Il Goiello" in Arcetri, near Maria Celeste’s convent.Maria Celeste’s convent. Maria Celeste takes care of him until she dies in 1634. Maria Celeste takes care of him until she dies in 1634.

► Comes back to his earlier studies of motionComes back to his earlier studies of motion 1638: 1638: Discourses and Demonstrations Concerning Two Discourses and Demonstrations Concerning Two

New SciencesNew Sciences published at Leyden published at Leyden RelativityRelativity

► 1635: 1635: DialogueDialogue... translated into Latin and English... translated into Latin and English Banned in Catholic countries, but available in Protestant Banned in Catholic countries, but available in Protestant

landslands

► He dies in 1642, the year Isaac Newton is born, 300 He dies in 1642, the year Isaac Newton is born, 300 years before Steven Hawking is bornyears before Steven Hawking is born

EpilogueEpilogue

► 1820: The Papal Inquisition is abolished1820: The Papal Inquisition is abolished► 1835: 1835: Dialogue Concerning the Two Chief Dialogue Concerning the Two Chief

World SystemsWorld Systems is taken off the Vatican's list is taken off the Vatican's list of banned booksof banned books

► 1992: The Catholic Church formally lifts the 1992: The Catholic Church formally lifts the edict of inquisition on Galileoedict of inquisition on Galileo Steven Hawking was invited to the ceremonySteven Hawking was invited to the ceremony Gave a talk on the Big BangGave a talk on the Big Bang

► the late Pope John Paul II once told him that scientists the late Pope John Paul II once told him that scientists should not study the beginning of the universe because should not study the beginning of the universe because it was the work of Godit was the work of God

► Here we go again?Here we go again?