Galileos Sidereus Nuncius and our perception of the

Galileo’s “Sidereus Nuncius” and our perception of the Universe Massimo Robberto STSc. I Feb. 24, 2009 Loyola College in Maryland

Venice, 1609 Feb. 24, 2009 Loyola College in Maryland

Feb. 24, 2009 Loyola College in Maryland

New Maritime Technologies Better Maps Hartman Astrolabe (1532) Mariner’s Compass (Chinese) Sextant

Ian Vermeer De astronoom, 1668 Feb. 24, 2009 Loyola College in Maryland

Hans Lippershey (Amsterdam, ca. 1600) the “looker” (spyglass, eyeglass) Feb. 24, 2009 Loyola College in Maryland

Venice, 1609 Feb. 24, 2009 Loyola College in Maryland

Galileo Galilei (1564 -1642) by D. Robusti, 1606 Feb. 24, 2009 Loyola College in Maryland

Galileo’s cannocchiale Feb. 24, 2009 Loyola College in Maryland

Selling the cannocchiale “ The power of my cannocchiale [telescope] to show distant objects as clearly as if they were near should give us an inestimable advantage in any military action on land or sea. At sea, we shall be able to spot their flags two hours before they can see us; and when we have established the number and type of the enemy craft, we shall be able to decide whether to pursue and engage him in battle, or take flight. Similarly, on land it should be possible from elevated positions to observe the enemy camps and their fortifications. “ Feb. 24, 2009 Loyola College in Maryland

Galileo’s telescope Feb. 24, 2009 Loyola College in Maryland

Feb. 24, 2009 Loyola College in Maryland

Like a “Letter to Nature” announcing the discovery of: n n n n Astronomical Telescope Structure of the Moon surface Enormous number of stars invisible to the naked eye Nature of the Milky Way Existence of Nebulae Jovian Planets Evidence in support of Copernican system Feb. 24, 2009 Loyola College in Maryland

The Moon n n The surface of the moon is not a perfect sphere. There are mountains and valleys and “perfect circles”. Feb. 24, 2009 Loyola College in Maryland

Feb. 24, 2009 Loyola College in Maryland

Feb. 24, 2009 Loyola College in Maryland

New stars Feb. 24, 2009 Loyola College in Maryland

the Milky Way our galaxy you are here Feb. 24, 2009 Loyola College in Maryland

Nebulae Feb. 24, 2009 Loyola College in Maryland

Nebulae Feb. 24, 2009 Loyola College in Maryland

Star and Planet Formation in Orion Feb. 24, 2009 Loyola College in Maryland

Photoevaporation of circumstellar disks Feb. 24, 2009 Loyola College in Maryland

Orion Proplyds Feb. 24, 2009 Loyola College in Maryland

Jovian Planets Feb. 24, 2009 Loyola College in Maryland

“Medicei” satellites Io Feb. 24, 2009 Europa Ganymedes Loyola College in Maryland Callisto

Io Galileo NASA probe IRTF (Hawaii) – Infrared Image With over 400 active volcanoes, Io is the most geologically active object in the Solar System Feb. 24, 2009 Loyola College in Maryland

Ptolemaic vs. Copernican system Feb. 24, 2009 Loyola College in Maryland

Where was the problem? n n The moon revolves around the Earth. Why should not the other planets do the same? Galileo’s point: 1) 2) 3) If Jupiter has 4 moons The Earth has one moon Then Earth is no special; planets may have satellites! Conclusion: Jupiter moons support Copernican system Feb. 24, 2009 Loyola College in Maryland

Aristotle’s cosmos n n n The heavens, starting at the Moon, were the realm of perfection. The sublunary region was the realm of change and corruption. Christian philosophers liked the idea. Feb. 24, 2009 Loyola College in Maryland

Dante Alighieri (1264 -1321) Feb. 24, 2009 Loyola College in Maryland

Troubles begin Copernican system is elegant, however 1) 2) 3) A moving Earth seems to be a problem (no wind!) We do not see stellar parallaxes Circular orbits still problematic No silver bullet, yet. Feb. 24, 2009 Loyola College in Maryland

Stellar parallax Feb. 24, 2009 Loyola College in Maryland

Galileo answers 1) Everything moves with the Earth, including atmosphere. => Can you discern if a boat is moving or not in a perfectly calm see with uniform wind? DISCOVERY OF INERTIA! 2) No parallax because the stars are too far. 3) Circular orbit problem: ignored. 4) Silver bullet: new theory of tides (1616) WRONG! Feb. 24, 2009 Loyola College in Maryland

Galileo’s personality n n n n Frequent strokes of creative genius Visionary-far reaching Very often (but not always) right Profound knowledge of scholastic philosophy Sarcastic (more than ironic) Self-confident True catholic Feb. 24, 2009 Loyola College in Maryland

Galileo’s enemies in Florence n Niccolo’ Lorini (Dominican, 1612) u u n “that …Ipernico” “the devil’s sect of mathematicians…” Tommaso Caccini (Dominican, 1613) u u “Mens of Galilee, why you stay there looking at the sky? . . . ” Joshua commanded: “Move not, O sun, toward Gabaon…” This passage becomes a BIG PROBLEM: arguing that the Sun does not move is against the Bible Feb. 24, 2009 Loyola College in Maryland

1616 – first “process” n n n Lorini brings the case to S. Uffizio Galileo is not charged/defendant 2 sentences of Copernicus are condemned: u u u The Sun is is the center of the world and therefore immobile: UNCORRECT, ABSURD AND FORMALLY HERETIC The Earth is not the center of the world but it is in daily motion: DESERVES SAME CENSORSHIP IN PHILOSOPHY AND FROM THE P. O. V. OF THEOLOGICAL TRUTH IS AT LEAST AS WRONG IN WHAT CONCERNS FAITH. “De Revoluzionibus Orbium Coelestium” has to be corrected. In the meantime, it is forbidden. Feb. 24, 2009 Loyola College in Maryland

Meeting Bellarmino-Galileo: Feb. 26, 1616 n n Bellarmino calls immediately Galileo (as the champion of Copernicanism) 3 levels: u u u n n n Monitum Preceptum Prison Galileo receives a “monitum” The general secretary Seghizzi (dominican) still prepares the Preceptum; it is left unsigned in the folder. BIG ERROR. Bellarmino soon later writes a friendly letter to Galileo allowing him to discuss “in theory” the copernican system. Feb. 24, 2009 Loyola College in Maryland

1623: il Saggiatore (“The Assayer”) n In 1619 G. starts a controversy with Orazio Grassi (Jesuit astronomer) over the nature of Comets u u Grassi: An Astronomical Disputation on the Three Comets of the Year 1618 Guiducci (G. ): Discourse on the Comets Grassi (“Lotario Sarsi”): The Astronomical and Philosophical Balance Galileo: The Assayer t t Feb. 24, 2009 Dedicated to Pope Urbano VIII Galileo’s scientific manifesto A masterpies of polemical literature Alienates many of his Jesuits friends Loyola College in Maryland

Urbano VIII n n n Aug. 16, 1623: Card. Maffeo Barberini of Florence, Galileo friends and great estimator, becomes Pope Urbano VIII. A new age? Galileo start working on the Dialog Concerning the Two Chief World Systems. u u Salvati/Sagredo/Simplicio 4 days Formally neutral, it is blatantly biased pro-copernicus Completed in 1629, printed in 1631 after approval from the inquisition. Feb. 24, 2009 Loyola College in Maryland

Disaster with Urbano VIII n n n The Dialog ends with Simplicio making a shallow observation: “God… could have made the universe any way he wanted to and still made it appear to us the way it does” This is the point Pope had explicitly asked to address Galileo puts these words in the mouth of Simplicio and does not really bother to expand on the argument: The end of a friendship Feb. 24, 2009 Loyola College in Maryland

Note on Pope’s point n n Galileo had no “proofs”. His point is: “If Copernicus is right, then tides have a simple and elegant explanation. ” Is this LOGICALLY right? If something is “reasonable”, is it also “true”? Can we reach certainty about reality (“penetrate the design of God”) by observing and explaining phenomena? Can you “rationally” know something on the basis of experimental science? Feb. 24, 2009 Loyola College in Maryland

Epilogue n n n Pope is VERY angry Process starts immediately “Preceptum” (unsigned) is found in the 1616 folder Galileo has the letter of Bellarmino (dead in the meantime) but it does not really help Galileo is condemned in 1633 u u u “vehemently suspect of heresy”, he is required to “abjure, curse and detest” those opinions Ordered imprisoned, commuted to house arrest The “Dialog” is banned. t Feb. 24, 2009 After the trial, all his works, past and future, are forbidden Loyola College in Maryland

Arcetri, il Gioiello Feb. 24, 2009 Loyola College in Maryland

Still active, almost completely blind, Galileo will write his final masterpiece “Discourses and Mathematical Demonstrations Relating to Two New Sciences “ (1638) setting the foundations of Physics. Feb. 24, 2009 Loyola College in Maryland

Galileo’s legacy Feb. 24, 2009 Loyola College in Maryland

Earth and Moon from Mars Feb. 24, 2009 Loyola College in Maryland

Earth and Moon from. Loyola Saturn (Cassini) College in Maryland Feb. 24, 2009

“Copernican Principle” n n Earth Sun Galaxy … is not the center of the Universe Principle of “mediocrity” Fundamental assumption of modern physics and cosmology Feb. 24, 2009 Loyola College in Maryland

The foundation of Science n "Philosophy is written in this grand book, the universe. . . It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures; . . . " Nature is intelligible Feb. 24, 2009 Loyola College in Maryland

Conclusion “It looks to me as something almost incredible that an invention of the human intellect and the structure of the universe coincide; the mathematics we invent gives really access to the nature of the universe and makes it useful for us. Therefore the intellectual structure of the human subject and the objective structure of reality coincide: the subjective reason and the reason “objectivated” of nature are identical. Feb. 24, 2009 Loyola College in Maryland

I think that this coincidence between what we have thought and how nature realizes itself and behaves is an enigma and a great challenge, because we see that, at the end, it is “ONE” reason that connects both: our reason could not discover the other one if it would not be an identical reason that precedes both. ” Benedict XVI, Rome , April 6 2006 Feb. 24, 2009 Loyola College in Maryland