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Home , Erasmus Reinhold, Harmonices Mundi, Prutenic Tables, Sidereus Nuncius, Tommaso Caccini

This Friday: Houghton Library Visit, 10-11am !

meet in lobby of Houghton Library at 10am pls travel light (we’ll put our things in a locker) bring a quarter if you can (they have them too) Lecture 10: ! the reception of Copernicus 1543 to 1616 ! -few paid any attention to (“hypothesis” as “model”) ! -a rival theory with the best of both systems ( and his better data) ! -only a few Copernicans: , Bruno ! -source of conflict: Tridentine Church + Copernicus’s De Rev (1543) ! a reworking of ’s Almagest that inverts the places of and sun ! very technical in Latin ! the oldest science but not highly ranked in university hierarchy Hierarchy of the disciplines in the medieval and Renaissance university

Theology Law Medicine

Arts faculty: study philosophy

preparatory studies: 7 liberal arts arithmetic, geometry, , astronomy () grammar, rhetoric, dialectic (trivium) Motions of the earth in the Copernican system ! 1. diurnal rotation (day and night) ! 2. annual of the earth around the sun (seasonal variations) ! + 3. a “trepidation” which accounts for precession of equinoxes (which caused a long slow drift of the equinox from its date) [don’t need to know this] Problems posed by heliocentrism: ! requires a new physics ! requires a near infinite universe + looks silly ! requires a new interpretation of some verses in the Bible ! ! !

Erasmus Reinhold,! (1551)! using Copernicus’! model and parameters! ! =instrumentalist use! of heliocentrism Tychonic system: ! geo-helio- centrism= ! best of both?? Tycho Brahe (1546-1601), Danish nobleman, received “big science” funding from King of DK, then from Rudolph II in Prague. =science outside univeristies ! Employed assistants (incl Kepler in Prague), had giant metal instruments made to get more precise observations than anyone had ever had (to 2” of arc). ! Here title page of his self-published book about his instruments What is Tycho Brahe’s religion? ! Tycho’s island: Hveen Uraniborg: a house for people and astro instruments Sterneborg: an extra observatory, mostly underground Tycho and his giant quadrant detail: notice the system of graduating the instrument, invented by Tycho other detail: assistants using an armillary sphere and a sextant Tycho Brahe uses his great new data to support his system: ! geoheliocentrism (1571-1630) will use Tycho’s data after his death to support heliocentrism

Kepler’s guiding conviction: “You [God] ordered all things by measure, number and weight.” (Wisdom 11:21) (secret of the universe), 1596: the distances of the from the sun are explained by perfect solids nested between the planetary orbs. But he later doubted this scheme.

From Kepler’s laborious calculations from Tycho’s data: ’ orbit is an ellipse! (K’s 1st law) Also notices that the sweeps out equal areas in equal times (2nd law) ! pub’d in (1609) In Astronomia nova,1609 Kepler concludes empirically that planetary are elliptical Kepler’s three laws of planetary motion:! 1. The orbit of every planet is an ellipse with the sun at one focus.! 2. A line joining a planet and the sun sweeps out equal areas during equal intervals of time! 3. The time it takes a planet to orbit around the sun is related to how far away the planet is from the sun. specifically: The squares of the periodic times are to each other as the cubes of the mean distances. Or: The orbital period of a planet squared is directly proportional to the cube of the semi-major axis of its orbit (the semi-major axis is the longest line crossing the area covered by the ellipse, and includes the 2 foci). ! In 1687 Newton’s Principia explained these laws as effects of the law of gravity. Until then no one understood their significance--but they were evidence that God used math in making the world. Figure 1: Illustration of Kepler's three laws with two planetary orbits. (1) The Harmonices Mundi (1619): harmonies of the world the planetary distances match musical harmonies + finds his 3rd law Frontispiece of the (1627), pub’d by Kepler from Tycho’s data-- the best tables ever (calculated from a Copernican system) detail: Kepler with a few coins showering down on him from above Giordano Bruno 1548-1600 —the ally you don’t need ! Dominican friar, with many heterodox ideas -no Trinity -no transsubstantiation -infinite and eternal worlds (incl copernicanism) etc. denounced in 1592 and executed for heresy Factor leading to conflict #1: ! Counter-Reformation crackdown on heterodoxy ! In doing philosophy is safe (Christianized by ); everything else is potentially unsafe. ! painting of the Council *Trent of Trent (1545-63) (in Santa Maria Trastevere, ) Decrees of the Council of Trent, 1545-63 ! “To control petulant spirits, the Council decrees that in matters of faith and morals pertaining to the edification of Christian doctrine, no one, relying on his own judgment and distorting the sacred scriptures according to his own conceptions shall dare to interpret them contrary to that sense which the holy mother Church to whom it belongs to judge their sense and meanings, has held and does hold, or even contrary to the unanimous agreement of the Church fathers, even though such interpretations should never at any time be published.” (Blackwell, p. 183) Very little Catholic reaction to Copernicus: ! one early objection: Florentine Dominican Giovanni Maria Tolosani in 1544 ms denounces Copernicus as absurd in philosophy and a violation of proper hierarchy of disciplines But also some enthusiasm: ! Diego de Zuñiga, 1536-97 Augustinian, taught at Univ of Salamanca ! In his commentary on Job (1584) Zuñiga argued that the Bible referred to motion of the earth in Job 9:6: “he who moves the earth from its place and its pillars are shaken.” He later rejected heliocentrism as incompatible with Aristotelian philosophy. In 1632 his commentary was put on the index. Factor #2: (1564-1642) ! taught math at Pisa then Padua but unhappy at the university ! always in debt (lives with a woman and has 3 children) ! 1611 appointed court mathematician in --his big break! View of Florence from the 16th century members of the Medici family-- Galileo’s patrons in Florence Galileo’s telescopes, Museum of the history of science in Florence ! combination of a convex and a concave lens inside a tube to create magnification ! magnification: X15-20 but small field of vision (15 arc minutes, or about 1/4 of the full moon) Galileo’s telescope =a refracting telescope; Gal’s best magnified up to 30x Title page of Galileo’s Starry Messenger (1610) announcing of =Medicean Sidereus nuncius: mountains and craters on the moon Galileo’s manuscript drawings of the moon as seen with a telescope: ! ! cf. a photograph of the moon Sidereus nuncius: ! with telescope noticing “stars” moving around Jupiter =moons Galileo, Sidereus nuncius (Starry messenger), 1610 reports of moons orbiting around Jupiter which he calls the Medicean stars. Responds to an objection to heliocentrism re earth’s moon the new, pock-marked moon look gets into art of the time! A new piece observation to support Copernicanism: ! phases of , observed by telescope published 1613 Text Heliocentrism predicts a full set of , as for the moon, which became visible with the telescope In the Ptolemaic system (left), Venus always lies between the sun and the earth [because empirically Venus never strays far from the sun positionally] and it would always show a crescent phase. The Copernican system (right) predicts a full range of phases for Venus as it passes from between the sun and the earth to being on the opposite side of the sun from the earth. (from Parvis Ansari http://artsci.shu.edu/physics/1007/historylv.html) Agnolo degli Erri, “Dominican preaching” ca. 1470 Galileo’s enemies: Dominican preachers in Florence; + university philosophers Triggers: ! Vocal enemies: Lodovico delle Colombe (1565-1616) =“pigeonists” ! Tommaso Caccini preaching against motion of the earth ! Unhelpful ally: Paolo Antonio Foscarini (1565-1616), Carmelite, writes in support of heliocentrism Condemnation of 1616 by the Congregation of the Index: ! 1. the sun is the center of the world, and is completely immobile by local motion. Censure: all agreed that this proposition is foolish and absurd in philosophy and is formally heretical, because it explicitly contradicts sentences found in many places in sacred scripture according to the proper meaning of the words and according to the common interpretation and understanding of the Holy Fathers and of learned theologians. ! 2. The earth is not the center of the world and is not immobile, but moves as a whole and also with a diurnal motion. Censure: All agreed that this proposition receives the same censure in philosophy and in respect to theological truth, it is at least erroneous in faith.