Galileo’s Daughter: A Drama of Science, Faith and Love. Dava Sobel

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СКАЧАТЬ when Galileo was born, the eldest son might well receive a Christian name derived from his parents’ surname. Accordingly, Vincenzio Galilei and his new wife, Giulia Ammannati Galilei, attracted no special attention when they gave the name Galileo to their first child, born at Pisa on the 15th day of February in the year of Our Lord 1564. (The year was actually recorded as 1563 in the chronicles of that period, however, when New Year’s Day fell on 25 March – the feast of the Annunciation.)

      The family name Galilei, ironically, had itself been created from the first name of one of its foremost favourite sons. This was the renowned doctor Galileo Buonaiuti, who taught and practised medicine during the early 1400s in Florence, where he also served the government loyally. His descendants redubbed themselves the Galilei family in his honour and wrote ‘Galileo Galilei’ on his tombstone, but retained the coat of arms that had belonged to the ancestral Buonaiutis since the thirteenth century – a red step-ladder on a gold shield, forming a pictograph of the word buonaiuti, which literally means ‘good help’. The meaning of the name Galileo, or Galilei, harks back to the land of Galilee, although, as Galileo explained on this score, he was not at all a Jew.

      Galileo Galilei took a few tentative steps along his famous forebear’s path, studying medicine for two years at the University of Pisa, before he gave himself over to the pursuit of mathematics and physics, his true passion. ‘Philosophy is written in this grand book the universe, which stands continually open to our gaze,’ Galileo believed. ‘But the book cannot be understood unless one first learns to comprehend the language and to read the alphabet in which it is composed. It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures, without which it is humanly impossible to understand a single word of it; without these, one wanders about in a dark labyrinth.’

      Galileo’s father had opposed the idea of his becoming a mathematician and tried, arguing from long personal experience with mathematics and patrician poverty, to dissuade his son from choosing such a poorly paid career.

      Vincenzio made a minimal living giving music lessons in the rented Pisan house where Galileo was born and partly raised. He also dabbled in the business dealings of his wife’s family, the Ammannati cloth merchants, to supplement his small teaching income, but he was at heart a composer and musical theorist in the days when musical theory was considered a special branch of mathematics. Vincenzio taught Galileo to sing and to play the organ and other instruments, including the recently remodelled lute, which became their favourite. In the course of this instruction he introduced the boy to the Pythagorean rule of musical ratios, which required strict obedience in tuning and composition to numerical properties of notes in a scale. But Vincenzio subjected these prevailing rules to his own studies on the physics of sound. Music, after all, arose from vibrations in the air, not abstract concepts regarding whole numbers. Using this philosophy, Vincenzio established an ideal tuning formula for the lute by fractionally shortening the intervals between successive frets.

      After Vincenzio moved to Florence with his wife in 1572, temporarily leaving Galileo behind in the care of relatives, he joined other virtuoso performers, scholars and poets bent on reviving classic Greek tragedy with music.^* Vincenzio later wrote a book defending the new trend in tuning that favoured the sweetness of the instrument’s sound over the ancient adherence to strict numerical relationships between notes. This book openly challenged Vincenzio’s own former music teacher, who prevented its publication in Venice in 1578. Vincenzio persevered, however, until he saw the work printed in Florence three years later. None of these lessons in determination or challenge to authority was lost on the young Galileo.

      ‘It appears to me’, Vincenzio stated in his Dialogue of Ancient and Modern Music, ‘that they who in proof of any assertion rely simply on the weight of authority, without adducing any argument in support of it, act very absurdly. I, on the contrary, wish to be allowed freely to question and freely to answer you without any sort of adulation, as well becomes those who are in search of truth.’

      When Galileo was ten, he journeyed across Tuscany to join his parents and his infant sister, Virginia, in Florence. He attended grammar school near his new home until his thirteenth year, then moved into the Benedictine monastery at Vallombrosa to take instruction in Greek, Latin and logic. Once there, he joined the order as a novice, hoping to become a monk himself, but his father wouldn’t let him. Vincenzio withdrew Galileo and took him home, blaming an inflammation in the youth’s eyes that required medical attention. Money more likely decided the issue, for Vincenzio could ill afford the down payment and regular upkeep required to support his son in a religious vocation that generated no income. A girl was different. Vincenzio would have to pay dowries for his daughters, either to the Church or to a husband, and he could expect no return on either investment. Thus Vincenzio needed Galileo to grow up gainfully employed, preferably as a doctor, so he could help support his younger sisters, now four in number, and two brothers.

      Vincenzio planned to send Galileo back to Pisa, to the College of the Sapienza, as one of forty Tuscan boys awarded free tuition and board, but couldn’t obtain the necessary scholarship. A good friend of Vincenzio’s in Pisa offered to take Galileo into his own home, to reduce the cost of the boy’s education. Vincenzio, however, hearing that this friend was romancing one of Galileo’s Ammannati cousins, held off for three years until the love affair ended in marriage and made the house a respectable residence for his son.

      In September of 1581, Galileo matriculated at the University of Pisa, where medicine and mathematics both fitted into the Faculty of Arts. Although he applied himself to the medical curriculum to please his father, he much preferred mathematics from the moment he encountered the geometry of Euclid in 1583. After four years of formal study, Galileo left Pisa in 1585, at the age of twenty-one, without completing the course requirements for a degree.

      Galileo returned to his father’s house in Florence. There he began behaving like a professional mathematician – writing proofs and papers in geometry, going out to give occasional public lectures, including two to the Florentine Academy on the conic configuration of Dante’s Inferno, and tutoring private students. Between 1588 and 1589, when Vincenzio filled a room with weighted strings of varying lengths, diameters and tensions to test certain harmonic ideas, Galileo joined him as his assistant. It seems safe to say that Galileo, who gets credit for being the father of experimental physics, may have learned the rudiments and value of experimentation from his own father’s efforts.

      Having impressed several established mathematicians with his talent, Galileo procured a teaching post at the University of Pisa in 1589 and returned once more to the city of his birth at the mouth of the River Arno. The flooding of the river in fact delayed Galileo’s arrival on campus, so that he missed his first six lectures and found himself fined for these absences. By the end of the year, the university authorities were docking his pay for a different sort of infraction: his refusal to wear the regulation academic regalia at all times.

      Galileo deemed official doctoral dress a pretentious nuisance, and he derided the toga in a three-hundred-line verse spoof that enjoyed wide readership in that college town. Any kind of clothing got in the way of men’s and women’s frank appraisals of each other’s attributes, he argued in ribald rhyme, while professional uniforms hid the true merits of character under a cloak of social standing. Worse, the dignity of the professor’s gown barred him from the brothel, denying him the evil pleasures of whoring while resigning him to the equally sinful solace of his own hands. The gown even impeded walking, to say nothing of working.

      A long black robe would surely have hindered Galileo’s progress up the Leaning Tower’s eight-storey spiral staircase, laden, as legend has it, with cannonballs to demonstrate a scientific principle. In that infamous episode, the weight of iron on the twenty-five-year-old professor’s shoulders was as nothing compared to the burden of Aristotelian thought on his students’ perceptions of reality. Not only Galileo’s classes at Pisa, but university communities all over Europe, honoured the dictum of Aristotelian physics СКАЧАТЬ