the scientist as a young man!Galileo and Pisa

Alessandro Pascolini"Pisa, International Conference on

Quantum Dots, May 2014"

Conference poster

Commonplace image

Our image !

Pisa

The pendulun "

From the tower

Galileo and Pisa!~ 1564-1574 primary education!~ 1580-1585 enrolled in the faculty of artists of! the university as student of medicine!~ 1589-1592 lecturer in mathematics at the! university !~ 1600-1642 life appointment as “Chief! Mathematician of the University of Pisa and! Philosopher and Mathematician to the! Grand Duke" of Tuscany” ! - no teaching duty – never at Pisa!

From his own horoscopes we know that he was born on February 16 (Julian calender) 1564!at 4 or 3.30 pm !(the times of horoscopes are sometimes altered to produce a more favourable distribution of planets in hauses)"

Birthplace!

status at the end of XVIII century"

Galileo and Florence"

The Galilei were a noble florentine family, but due to economic difficulties his grand-grand father John moved to the village of Santa Maria del Monte, loosing the citizenship."Galileo always prided himself on being a noble of Florence, but only on November 1628 he obtained from the Grand Duke the florentine citizenship, replacing the one of Santa Maria del Monte. "He never was of Pisan citizenship"

His parents had a great influence on Galileo"

Vincenzo Galilei (1520-91)!musician (addicted) and "merchant (reluctant) !

Giulia Ammanati (1538-1620)"

Galileo two main problems most of his life long:!- his mother!- lack of money !

She brought young Galileo before the Holy Office (the Inquisition) in Florence for calling her names—puttana, gabrina (harlot, crone)—and the obliging inquisitor issued an admonition to the exasperated son. !The nasty ugly old witch Gabrina is a character in Ariosto's Orlando furioso, which Galileo admired much. !

On the occasion of 1604 inquisition by the Holy Office on Cremonini and Galileo, Silvestro Pagnoni (one of Galileo’s technicians) duly relayed Giulia’s confidences to the inquisitor:!“I've understood from his mother that he never makes confession or takes communion, and she asked me to find out whether he went to mass on feast days. I observed that instead of going to mass he went to the house of his Venetian prostitute Marina....” !

Vincenzo Galilei"

Giovanni de’ Bardi and his “Camerata”"

Vincenzo Galilei was a theorist of integrity. "He did not just reject authority but showed by "sensory experience and necessary demonstration” "

There are three different ways in which the tone of a string may be sharpened, namely, by shortening it, by stretching it and by making it thinner. "

The best that can be done when instruments play together or accompany singers is to forget the perfect ratios of the various modes and tune everything to equal temperament."

Dialogo della musica antica, 1581"

From “la musica”

Vallombrosa Abbey"

VincenzoViviani"

“Erano tra tanto i suoi più grati trattenimenti nella musica pratica e nel toccar li tasti e il leuto, nel quale, con l'esempio et insegnamento del padre suo, pervenne a tanta eccellenza, che più volte trovossi a gareggiare co' primi professori di que' tempi in Firenze et in Pisa, essendo in tale strumento ricchissimo d'invenzione, e superando nella gentilezza e grazia del toccarlo il medesimo padre; qual soavità di maniera conservò sempre sino alli ultimi giorni. !

Trattenevasi ancora con gran diletto e con mirabil profitto nel disegnare; in che ebbe così gran genio e talento, ch'egli medesimo poi dir soleva agl'amici, che se in quell'età fosse stato in poter suo l'eleggersi professione, avrebbe assolutamente fatto elezione della pittura.”!

" " " " " "Viviani"

Horti medici pisani"

Medicine and Aristotle!

The course in medicine required some knowledge of Aristotelian physics. Pisa had two able expositors of the subject, Francesco Buonamici and Girolamo Borro. !Each taught a rigid Aristotelianism without agreeing on its principles, although both had a deep respect for the integrity of the philosophy they interpreted and a deep disdain for the compromises required to subject Greek philosophy to Christian theology. !Borro and Buonamici set the agenda for Galileo's physics. !

Mathematics replaces medicine!

In 1583, Galileo, the disaffected medical student, met the mathematician Ostilio Ricci the instructor of the grand-ducal pages. Galileo heard a lecture or two of Ricci's on Euclid. !With that instruction he mastered Euclid's Elements almost on his own and showed such promise that his teacher advocated his release from medicine. Vincenzo agreed most reluctantly. He too liked mathematics, or anyway arithmetic, which he employed in his musical theorizing, but he knew that mathematicians were no more prosperous than lutenists.!

libris

A carrier in mathematics !

With Ricci's encouragement and Vincenzo's agreement, Galileo spent his first post-nongraduate years preparing himself desultorily for the insignificant post of a mathematics professor. !According to the traditional ranking of the sciences, philosophers and physicians occupied the top of the academic ladder, mathematicians and grammarians the bottom. !Galileo was not the sort to sit contentedly on lower rungs. Nor did he expect to. Some well-placed mathematicians were arguing, occasionally successfully, that their work deserved greater respect than philosophers accorded it. !

Christopher Clavius, Ostilio Ricci"

Guidobaldo and Francesco Maria del Monte "

libris

Alessandro Vellutello,1544!Bernardino Daniello, 1568!

Giovanni Sodano’s painting of Dante’s hell!according to Antonio Manetti’s proposal and calculations by Galileo!~1590"

1587 (88?)!Galileo’s!mathe-matics !of hell"

Dante’s hell according to Manetti!

Accademia della Crusca, 1595"

archimedes

La bilancetta"

1) start by hanging a sample of pure gold from the hook, and with the pan’s suspension in its “home” position bring the balance into equilibrium; !2) then immerse the gold in a container of water and slide the pan’s suspension along the rod until the balance is again in equilibrium; !3) mark the position of the suspension on the rod; this will be the “gold” point; 4) repeat these three steps with a sample of pure silver thereby establishing a “silver” point; 5) finally, install the special ruler between the two established “points”;! 6) To test a suspect sample, simply repeat the first two steps using that sample; if the pan’s point of suspension then falls somewhere between the two previously established points, it is a mix, and its relative distances to those points will be in the ratio of the rel­ative amounts of each component. "

To create a ruler designed for the Archimedean problem, testing a possible fraud and measuring the relative amounts of gold and silver in it: "

What did Galileo use for the special rule? !Here he shows some nice opportunistic ingenuity. He used a fine wire (he did not say so, but a good guess would be a standard steel lute string) which he wound tightly and compactly around the balance arm in the space between the two points. !Then, since visually counting the wires to complete a measurement would have been difficult (the eyes glaze over), he recommended drawing the point of a stiletto across the wires between the points to be measured. A combination of the slight sound resulting from the passing of the point of the knife from one wire to another and the tactile feel of that same jump through the handle of the knife would allow an accurate count. !

The pendulun "

“In questo mentre con la sagacità del suo ingegno inventò quella semplicissima e regolata misura del tempo per mezzo del pendulo, non prima da alcun altro avvertita, pigliando occasione d'osservarla dal moto d'una lampada, mentre era un giorno nel Duomo di Pisa; e facendone esperienze esattissime, si accertò dell'egualità delle sue vibrazioni, e per allora sovvennegli di adattarla all'uso della medicina per la misura della frequenza de' polsi, con stupore e diletto de' medici di que' tempi e come pure oggi si pratica volgarmente: della quale invenzione si valse poi in varie esperienze e misure di tempi e moti, e fu il primo che l'applicasse alle osservazioni celesti, con incredibile acquisto nell'astronomia e geografia.”!

" " " " " "Viviani!

Lamp at Pisa cathedral by Vincenzo Possenti, 1586"

Pierot

Lamp of the Pisa cathedral at up to 1586, now at Camposanto"

Tycho Brahe !in his observatory"

nocturnal and Sundial

Galileo’s escapement"

Music, pendolum and the harmonic oscillator"

“Dialogues Concerning Two New Sciences”!

SALV. First of all one must observe that each pendulum has its own time of vibration so definite and determinate that it is not possible to make it move with any other period [altro periodo] than that which nature has given it. For let any one take in his hand the cord to which the weight is attached and try, as much as he pleases, to increase or diminish the frequency [frequenza] of its vibrations; it will be time wasted.!

A string which has been struck begins to vibrate and continues the motion as long as one hears the sound [risonanza]; these vibrations cause the immediately surrounding air to vibrate and quiver; then these ripples in the air expand far into space and strike not only all the strings of the same instrument but even those of neighboring instruments.!

“Dialogues Concerning Two New Sciences”!

SALV. But now before proceeding any farther I want to call your attention to the fact that, of the three methods for sharpening a tone, the one which you refer to as the fineness of the string should be attributed to its weight.!

Returning now to the original subject of discussion, !I assert that the ratio of a musical interval is not immediately determined either by the length, size, or tension of the strings but rather by the ratio of their frequencies, that is, by the number of pulses of air waves which strike the tympanum of the ear, causing it also to vibrate with the same frequency.!

Pierot

University of Pisa"

Professor in Pisa!

Galileo's official teaching at Pisa did not go beyond the Elements and the Sphere, that is, the first five books of Euclid and a commentary on the Sphaera of John of Sacrobosco, a short summary of the first principles of astronomy. !In addition to the Elements and the Sphere, Galileo taught astrology to medical students who needed it to determine when not to bleed a patient.!Of original mathematical work by Galileo during this period there is not a trace. "

Capitolo contro il portar la toga !The authorities insisted that professors don their academic gowns when in the town as well as when discharging their university duties, on pain of the substantial fine of half a scudo. !Galileo so hated this imposition that he wrote a lengthy and irreverent poem against it, in the style of the critical-satirical digressive poems of Francesco Berni. The poem tells something about his pursuits and attainments at the age of 25. !Many sacred cows came to slaughter by his sharp wit: university officials, ecclesiastics, academics, philosophers, idiots. And many youthful preoccupations leave their marks: sex, wine, clothes, money.!

The worst thing in the world is—clothes. Clothes are the source of all deceit. In the good old times, everyone knew what everyone else was good for. A prospective bride could see the equipment other proposed mate, "See if he is too small, or has French diseases / Thus informed, take or leave him as she pleases.” !When people went naked there were no counts, marquises, servants, or paupers. The devil invented clothes as he devised artillery and witches—to the devil with clothes!!Oh if only men were made like the wine flasks used in taverns, which have so little decoration you can see right through them:!

"And yet they are filled with such excellent wine !"It's not surprising if throughout the city !"They say that it's splendid and even divine. !"Bottles, however, straw-covered and pretty !"When opened you'll find to be chock full of sin !"Wine slimy or wat'ry, perfumed or gritty, !"In dec'rative flasks good only to piss in.!

Galileo and Mazzoni!

Galileo interacted with Mazzoni, learning from him philosophy and helping in looking for decisive examples of the errors Aristotle had committed by depreciating mathematics. Something of the content of their conversations can be inferred from Mazzoni's concordist treatise In universam Platonis et Aristotelis philosophiam praeludia, not printed until 1597, Galileo's response to it, and Galileo's unpublished writings De motu antiquiora. These last consist of scattered notes, a brief dialogue, and two drafts of a treatise, all in Latin. They date from around 1590. The dialogue can be read as a record of the lost conversations between Galileo and Mazzoni.!

From the tower

“et allora, con gran sconcerto di tutti i filosofi, furono da esso convinte di falsità, per mezzo d'esperienze e con salde dimostrazioni e discorsi, moltissime conclusioni dell'istesso Aristotele intorno alla materia del moto, sin a quel tempo state tenute per chiarissime et indubitabili; come, tra l'altre, che le velocità de' mobili dell'istessa materia, disegualmente gravi, movendosi per un istesso mezzo, non conservano altrimenti la proporzione delle gravità loro, assegnatagli da Aristotele, anzi che si muovon tutti con pari velocità, dimostrando ciò con replicate esperienze, fatte dall'altezza del Campanile di Pisa con l'intervento delli altri lettori e filosofi e di tutta la scolaresca; e che né meno le velocità di un istesso mobile per diversi mezzi ritengono la proporzion reciproca delle resistenze o densità de' medesimi mezzi, inferendolo da manifestissimi assurdi ch'in conseguenza ne seguirebbero contro al senso medesimo .”!

" " " " " "Viviani!

Galileo's dialogue "De motu" begins with a few questions from Dominucus:!1. Does a point of rest intervene "at reflection," where a body thrown upwards begins its descent?!2. What reason can you give that a wooden body of equal size with an iron one will fall faster though it is lighter—if you accept that it will?!3. Why is natural motion faster at the end than at the beginning, and violent motion faster at the beginning than in the middle, and faster in the middle than at the end?!4. Why does the same body descend more speedily in air than in water, yet some bodies fall in air but float in water?!5. What reason can you give that a cannon ball carries further in a straight line if fired at an angle than if fired horizontally, although the vertical is more opposed to natural motion?!6. Why do the same guns shoot heavier balls further than light ones, and iron balls further than wooden ones, although the lighter offer less resistance to the "impelling force"? "

Pierot

Lucentio: I have Pisa left and I am to Padua come as he that leaves a shallow plash to plunge into the deep, and with satiety seeks to quench his thirst. ! (Shakespeare, The taming of the shrew, act one scene I)"