Galileo’sGalileo’s Dilemma:Dilemma: Ptolemy,Ptolemy, Copernicus,Copernicus, andand thethe TransformationTransformation ofof thethe HeavensHeavens
Dr.Dr. FrankFrank SummersSummers SpaceSpace TelescopeTelescope ScienceScience InstituteInstitute JanuaryJanuary 9,9, 20072007 GalileoGalileo –– TriumphTriumph andand TrialsTrials z 15641564--16421642 z WideWide rangerange ofof discoveriesdiscoveries inin physicsphysics andand astronomyastronomy z FirstFirst telescopictelescopic astronomerastronomer z TrialTrial byby thethe InquisitionInquisition “The bible was written to show us how to go to heaven, not how the heavens go.” Cardinal Baronius (1598)
1615 – Letter to the Grand Duchess Christina 1632 – Dialogue Concerning the Two Chief World Systems
Galileo’sGalileo’s DilemmaDilemma z 16151615 –– HolyHoly OfficeOffice examinesexamines CopernicusCopernicus z Corrections:Corrections: “theory”“theory” shouldshould bebe “hypothesis”“hypothesis” z GalileoGalileo orderedordered notnot toto teachteach heliocentrismheliocentrism z IfIf irrefutableirrefutable proof,proof, mattermatter couldcould bebe reopenedreopened z ImpliedImplied challengechallenge z GivenGiven thethe sciencescience ofof thethe earlyearly 1600s,1600s, couldcould GalileoGalileo provideprovide irrefutableirrefutable proofproof ofof thethe heliocentricheliocentric hypothesis?hypothesis? MotionsMotions ofof thethe HeavensHeavens z SunSun z MoonMoon z StarsStars z WanderersWanderers
ScientificScientific HeritageHeritage z PythagorasPythagoras (569(569--475475 BC)BC) z PlatoPlato (428(428--348348 BC)BC) z TheaetusTheaetus ofof AthensAthens (417(417--369369 BC)BC) z EudoxusEudoxus ofof CnidusCnidus (400(400--347347 BC)BC) z AristotleAristotle (384(384--322322 BC)BC) z CallippusCallippus ofof CyzicusCyzicus (370(370--300300 BC)BC) z EuclidEuclid (325(325--265265 BC)BC) ScientificScientific HeritageHeritage z AristarchusAristarchus ofof SamosSamos (310(310--230230 BC)BC) z ArchimedesArchimedes (287(287--212212 BC)BC) z ErasthonesErasthones ofof AlexandriaAlexandria (276(276--195195 BC)BC) z AppolloniusAppollonius ofof PergePerge (240(240--190190 BC)BC) z HipparchusHipparchus ofof NicaeaNicaea (190(190--120120 BC)BC) ClaudiusClaudius PtolemyPtolemy z AboutAbout 100100--175175 ADAD z Alexandria,Alexandria, EgyptEgypt z MathematicalMathematical SystematicSystematic TreatiseTreatise,, circacirca 150150 z ManyMany otherother booksbooks onon Astronomy,Astronomy, PhysicsPhysics z NotNot anan EgyptianEgyptian kingking GeocentricGeocentric ModelModel z EarthEarth atat center,center, stationarystationary z Moon,Moon, Mercury,Mercury, Venus,Venus, Sun,Sun, Mars,Mars, Jupiter,Jupiter, Saturn,Saturn, starsstars z PredictPredict significantsignificant eventsevents SunSun andand SeasonsSeasons
March 21 Spring Vernal Equinox 00:07
June 21 Summer Summer Solstice 18:06
Sept 23 Fall Autumnal Equinox 09:51
Dec 22 Winter Winter Solstice 06:08 Summer Solstice
Autumnal Vernal Equinox Equinox
Winter Solstice Summer Solstice
Autumnal Vernal Equinox Equinox
Winter Solstice Summer Solstice
91.3 days 91.3 days
Autumnal Vernal Equinox Equinox
91.3 days 91.3 days
Winter Solstice SunSun andand SeasonsSeasons
Vernal March 21 Spring 92.8 days Equinox 00:07
Summer June 21 Summer 93.7 days Solstice 18:06
Autumnal Sept 23 Fall 89.8 days Equinox 09:51
Winter Dec 22 Winter 89.0 days Solstice 06:08 Summer Solstice
92.5 days 94.5 days
Autumnal Vernal Equinox Equinox
88.1 days 90.1 days
Winter Solstice Summer Solstice
92.5 days 94.5 days
Autumnal Vernal Equinox Equinox
88.1 days 90.1 days
Winter Solstice
GeometricGeometric OrbitOrbit ModelsModels z EccentricEccentric circlecircle z CircularCircular motionmotion observedobserved fromfrom offoff--centercenter z DeferentDeferent circlecircle andand epicycleepicycle z CircularCircular motionmotion aboutabout circularcircular motionmotion z EquantEquant motionmotion z CircularCircular motionmotion wrtwrt toto offoff--centercenter pointpoint z CombinationsCombinations ofof thethe aboveabove t1 Circular Motion
t 2 t8
t 3 t7
t4 t6
t5 t1 Equant Motion
t2 t8
t3 t7
t4 t6
t5
ComplexComplex andand PowerfulPowerful z CompendiumCompendium z Gathered and extended Greek knowledge z Organized and justified with geometry and data (?) z Ptolemy’s Almagest vs Euclid’s Elements z PredictionPrediction z Positions on sky z Mathematical model z No disdistancestances in Almagest z No accounting for change in size z 1500 years MiddleMiddle AgesAges z 99th centurycentury ArabicArabic translationstranslations ofof “al“al--mjstymjsty”” z Variations/extensionsVariations/extensions toto PtolemaicPtolemaic modelsmodels z 11751175 LatinLatin translationtranslation ofof ArabicArabic translationtranslation z 15151515 FirstFirst printingprinting ofof AlmagestAlmagest
NicholasNicholas CopernicusCopernicus z 14731473--15431543 z CracowCracow University,University, Bologna,Bologna, Padua,Padua, FerraraFerrara z CanonCanon ofof thethe cathedralcathedral atat FrauenburgFrauenburg,, PolandPoland z ““littlelittle commentarycommentary onon hypotheseshypotheses ofof motionsmotions ofof heavenlyheavenly spheres”spheres” z NotNot published,published, selectivelyselectively distributeddistributed
1514 – Commentariolus (little commentary) 1543 – On the Revolutions of Heavenly Spheres MythMyth #1#1 z CopernicusCopernicus delayeddelayed publishingpublishing hishis workwork forfor fearfear ofof reprisalreprisal fromfrom thethe churchchurch MythMyth #1#1 z CopernicusCopernicus delayeddelayed publishingpublishing hishis workwork forfor fearfear ofof reprisalreprisal fromfrom thethe churchchurch z RealityReality checkcheck z CardinalCardinal SchSchöönbergnberg andand BishopBishop GieseGiese urgedurged CopernicusCopernicus toto publishpublish z BookBook waswas dedicateddedicated toto PopePope PaulPaul IIIIII MythMyth #2#2 z CopernicusCopernicus viewedviewed hishis systemsystem asas onlyonly aa mathematicalmathematical device,device, notnot realityreality MythMyth #2#2 z CopernicusCopernicus viewedviewed hishis systemsystem asas onlyonly aa mathematicalmathematical device,device, notnot realityreality z RealityReality checkcheck z AndreasAndreas OsianderOsiander insertedinserted introductoryintroductory letterletter z BishopBishop GieseGiese attemptedattempted toto getget letterletter removedremoved MythMyth #3#3 z Copernicus’Copernicus’ SunSun--centeredcentered modelmodel waswas muchmuch simplersimpler thanthan Ptolemy’sPtolemy’s EarthEarth-- centeredcentered modelmodel MythMyth #3#3 z Copernicus’Copernicus’ SunSun--centeredcentered modelmodel waswas muchmuch simplersimpler thanthan Ptolemy’sPtolemy’s EarthEarth-- centeredcentered modelmodel z RealityReality checkcheck z SimplicitySimplicity claimclaim inin CommentariolusCommentariolus z CopernicusCopernicus usedused eccentricseccentrics andand epicyclesepicycles z NoNo newnew mathematicalmathematical techniquestechniques MythMyth #4#4 z Copernicus’Copernicus’ SunSun--centeredcentered modelmodel waswas muchmuch moremore accurateaccurate thanthan Ptolemy’sPtolemy’s EarthEarth-- centeredcentered modelmodel MythMyth #4#4 z Copernicus’Copernicus’ SunSun--centeredcentered modelmodel waswas muchmuch moremore accurateaccurate thanthan Ptolemy’sPtolemy’s EarthEarth-- centeredcentered modelmodel z RealityReality checkcheck z NoNo greatergreater accuracyaccuracy inin predictionspredictions z NoNo significantsignificant advancesadvances inin observationsobservations usedused MythMyth #5#5 z AstronomersAstronomers embracedembraced Copernicus’Copernicus’ SunSun-- centeredcentered modelmodel MythMyth #5#5 z AstronomersAstronomers embracedembraced Copernicus’Copernicus’ SunSun-- centeredcentered modelmodel z RealityReality checkcheck z “Copernicans”“Copernicans” werewere few,few, eveneven aa centurycentury laterlater z GiordanoGiordano BrunoBruno burnedburned atat thethe stakestake inin 16001600 PtolemyPtolemy vsvs CopernicusCopernicus z ScientificScientific basisbasis z AlmagestAlmagest –– compendiumcompendium z RevolutionsRevolutions –– newnew ideasideas z HeritageHeritage z ThousandThousand yearsyears ofof refinementrefinement byby manymany z LoneLone partpart--timetime astronomerastronomer z CommonCommon sensesense z AbsurdityAbsurdity ofof EarthEarth motionmotion z AbsurdityAbsurdity ofof starstar motionmotion GalileoGalileo z 15641564--16421642 z ProfessorProfessor ofof MathMath atat PisaPisa andand PaduaPadua z MathematicianMathematician andand philosopherphilosopher toto GrandGrand DukeDuke atat FlorenceFlorence z Mountains on the Moon z Phases of Venus z “Galilean” moons of Jupiter z Innumerable stars in the Milky Way
z Ramifications z Aristotle wrong z Philosophical support for Copernicus
1610 – Starry Messenger TychonianTychonian ModelModel Galileo’sGalileo’s ProofProof z OnOn thethe TidesTides z Manuscript written in 1616 z Final argument of the Dialogue z Proposed title “On the flux and reflux of the tides” z ArgumentArgument z Earth’s motion produces advance and recession of the tides z ‘the ocean, because of its fluid nature, is the only thing that can indicate motion of the Earth’ z ‘if Earth were stationary, the tides could not occur’ Galileo’sGalileo’s ProofProof z ArgumentArgument (continued)(continued) z SmallSmall accelerationacceleration andand retardationretardation ofof Earth’sEarth’s motionmotion wouldwould createcreate tidestides (sloshing)(sloshing) z DailyDaily andand annualannual motionmotion ofof EarthEarth produceproduce fasterfaster speedspeed atat antisolarantisolar pointpoint andand slowerslower speedspeed atat subsolarsubsolar pointpoint GalileanGalilean TransformationTransformation
2 kph GalileanGalilean TransformationTransformation
2 kph
30 kph
Total 32 kph Subsolar point
Slower motion
Antisolar point
Rotational motion Faster motion
Orbital motion Galileo’sGalileo’s ProofProof z CounterCounter ArgumentArgument z FasterFaster andand slowerslower motionmotion isis withwith respectrespect toto thethe Sun,Sun, notnot EarthEarth z High/lowHigh/low tidestides cyclecycle inin aboutabout 1212 hourshours z TidesTides occuroccur relativerelative toto sublunarsublunar andand antilunarantilunar pointspoints Galileo’sGalileo’s ProofProof z CounterCounter ArgumentArgument z SimplicioSimplicio –– “the“the moon,moon, wanderingwandering throughthrough thethe sky,sky, attractsattracts andand drawsdraws upup towardtoward itselfitself aa heapheap ofof waterwater whichwhich goesgoes alongalong followingfollowing it,it, soso thatthat thethe highhigh seasea isis alwaysalways inin thatthat partpart whichwhich lieslies underunder thethe moon”moon” z SalviatiSalviati –– “the“the moonmoon travelstravels overover thethe wholewhole MediterraneanMediterranean everyevery day,day, butbut thethe waterswaters areare raisedraised onlyonly atat itsits easterneastern extremityextremity andand forfor usus herehere atat Venice”Venice” z SagredoSagredo –– “those“those ridiculousridiculous olderolder (opinions)"(opinions)" TransformationTransformation ofof thethe HeavensHeavens z GalileanGalilean transformationtransformation -- motionmotion isis relativerelative toto frameframe ofof referencereference z GeocentricGeocentric vsvs heliocentricheliocentric isis aa changechange ofof referencereference framesframes z TychonianTychonian systemsystem isis rotationalrotational transformationtransformation ofof CopernicanCopernican systemsystem
“Take note, theologians, that in your desire to make matters of faith out of propositions relating to the fixity of sun and earth you run the risk of eventually having to condemn as heretics those who would declare the earth to stand still and the sun to change position – eventually, I say, at such a time as it might be physically or logically proved that the earth moves and the sun stands still.” Note by Galileo in his own copy of Dialogue NewNew DataData z TychoTycho BraheBrahe 15461546--16011601 z AstronomerAstronomer toto KingKing FrederickFrederick IIII ofof DenmarkDenmark z ImperialImperial MathematicianMathematician toto EmperorEmperor RudolphRudolph IIII inin PraguePrague z ImprovementImprovement inin astronomyastronomy reliesrelies onon accurateaccurate observationsobservations NewNew IdeasIdeas z JohannesJohannes KeplerKepler 15711571--16301630 z 16001600 HiredHired byby BraheBrahe z 16011601 SucceededSucceeded BraheBrahe z 16091609 AstronomiaAstronomia NovaNova z Orbits as ellipses z Equal area in equal time z 16271627 RudolphineRudolphine tablestables NewNew MathematicsMathematics z IsaacIsaac NewtonNewton 16431643--17271727 z LucasianLucasian ProfessorProfessor ofof Mathematics,Mathematics, TrinityTrinity College,College, CambridgeCambridge z 16871687 PrincipiaPrincipia z Mathematical theory of gravity z Derives Kepler’s laws ReconciliationReconciliation z 19791979 –– PopePope JohnJohn PaulPaul IIII createscreates commissioncommission toto studystudy Galileo’sGalileo’s casecase z CommissionCommission concludesconcludes thatthat GalileoGalileo shouldshould notnot havehave beenbeen condemnedcondemned z 19921992 –– PopePope JohnJohn PaulPaul IIII publiclypublicly endorsedendorsed thethe commission’scommission’s findingsfindings z TheThe casecase hadhad becomebecome “the“the symbolsymbol ofof thethe church'schurch's supposedsupposed rejectionrejection ofof scientificscientific progress,progress, oror ofof 'dogmatic''dogmatic' obscurantismobscurantism opposedopposed toto thethe freefree searchsearch forfor truth."truth." ReferencesReferences z Ptolemy’sPtolemy’s AlmagestAlmagest,, GJGJ ToomerToomer (trans)(trans) z AlmagestAlmagest FlashFlash animations:animations: z http://www.csit.fsu.edu/~dduke/modelshttp://www.csit.fsu.edu/~dduke/models z TheoriesTheories ofof thethe WorldWorld fromfrom AntiquityAntiquity toto thethe CopernicanCopernican RevolutionRevolution,, MichaelMichael J.J. CroweCrowe z DialogueDialogue ConcerningConcerning thethe TwoTwo ChiefChief WorldWorld SystemsSystems,, StillmanStillman DrakeDrake (trans)(trans)