[VIII] Conjecture here among shadows
GALILEO’S COLLECTED CORRESPONDENCE brims with allusions to illnesses that often kept him from replying sooner to someone or forced him to close a letter in haste. Changes in the weather ‘molested’ him, his first biographer noted, and he typically fell sick in spring or autumn, or both, about every other year throughout his adult life. Although Galileo rarely elaborated on the nature of these health crises, he may have suffered from some form of relapsing fever contracted during the cave incident in Padua. Or he may have been a victim of malaria or typhoid, a common enough plight in Italy during that period. Another possible explanation for his pattern of repetitive malaise is an unspecified rheumatic disease, possibly gout, which could have accounted for the ‘very severe pains and twinges’ his biographer said he sustained ‘in various parts of his body’. Gout also causes painful kidney stones (when the excess uric acid in the blood, typical of this disease, gets deposited as crystals in the kidneys as well as in the joint spaces), and Galileo complained more than once of prolonged kidney trouble. The quantities of red wine he produced and drank would only have exacerbated the condition (by raising his uric acid level). Even at a time when wine was generally considered the safer alternative to water, doctors recognised the causal connection between alcohol and attacks of gout. Galileo’s daughter, who made many of his pills and tonics in the convent apothecary shop, frequently counselled him in her letters to limit ‘the drinking that is so hurtful to you’ because of the ‘great risk of getting sick’.
Other symptoms Galileo sometimes singled out for specific mention included chest pain, a hernia for which he wore a heavy iron truss, insomnia, and various problems with his eyes – particularly unfortunate for an astronomical observer. ‘As a result of a certain affliction I began to see a luminous halo more than two feet in diameter around the flame of a candle’, Galileo wrote of one such condition to a colleague, ‘capable of concealing from me all objects which lay behind it. As my malady diminished, so did the size and density of this halo, though more of it has remained with me than is seen by perfect eyes.’ His frequent telescope demonstrations may have predisposed him also to ocular infections, easily communicated by sharing an eyepiece.
After Galileo moved to Florence in 1610, poor health and long periods of recuperation frequently drove him out of the city into the surrounding hills. ‘I shall have to become an inhabitant of the mountains,’ Galileo vowed while he and his mother and the two little girls still resided on a city street, ‘otherwise I shall soon dwell among the graves.’
For several ensuing years he relied gratefully on the hospitality of his friend and follower Filippo Salviati, who rescued Galileo from the foul city air. At Salviati’s Villa delle Selve in the hills of Signa, fifteen miles west of Florence, Galileo spent enough time to write the better part of two books – Bodies in Water and Sunspot Letters – while convalescing from his typical ills. When his ready access to this retreat ended in 1614 with Salviati’s death, Galileo pressed the search for his own year-round haven.
In April of 1617, he took a fine villa atop the hill called Bellosguardo (‘beautiful sight’) on the south side of the River Arno, offsetting the high annual rent of one hundred scudi by selling the grain and broad beans grown on the property. From his new eyrie, Galileo enjoyed an unobstructed panorama of the heavens, with a downwards vista that swept the russet roofs, domed churches and city walls of Florence. To the east he could see the olive-green hillside of Arcetri, where his daughters lived inside the walled Convent of San Matteo. It took him three-quarters of an hour on foot or by mule – when he was up to the trip – to visit them.
Despite the salubrious atmosphere at Bellosguardo, however, another serious illness struck Galileo towards the end of 1617 and held him in its grip until spring came. In May 1618, thankful to be freed from his sickbed at last, he set out on a pilgrimage across the Apennine Mountains to the Adriatic coast, where he visited the ‘Casa Santa’ – the House of the Virgin Mary in Loreto. This former residence of the Blessed Virgin, according to local legend, had abruptly uprooted itself from the Holy Land in the year 1294 and flown on the wings of angels to the laurel grove (loreto in Italian) that gave the present town its name. Galileo had first talked of worshipping at the popular shrine in 1616, after he escaped unscathed from the Copernican uproar in Rome, but events and maladies had kept him from fulfilling that intention until now, when he could also offer thanks for his recent recovery and pray for improved health in the future.
He returned home in June to Bellosguardo and to his son, Vincenzio, whom he had brought from Padua in 1612 at the age of seven. By 1618, their male-dominated household also included two new students, Mario Guiducci and Niccolò Arrighetti, who, like Castelli before them and others to come after, would remain Galileo’s devoted friends for life. The thirtyish scholars busied themselves all that summer copying the master’s early theorems on motion, to help him return to the fundamental work he had forsaken in 1609 for the telescope. They mined the dense jumble of his Paduan notes and prepared neat sheets of paper, written extravagantly on one side only, for his review and revision.
In September, just when Galileo’s student assistants had finished this preliminary work, another bout of illness prevented him from building on it as planned. The delay might have been merely temporary, except that while Galileo languished, the heavens sent him a new mystery to ponder, and this apparition initiated a cascade of events that postponed the publication of his motion studies for another two decades.
A small comet glowed in the skies over Florence that September of 1618. Though unspectacular, as comets go, it was nevertheless the first comet to appear since the birth of the telescope. Other astronomers took to their rooftops with instruments of Galileo’s design, but Galileo himself remained indoors an invalid. Then another comet arrived in mid-November, while Galileo unfortunately fared no better than before. And even by the end of November, when a truly brilliant third comet burst on the scene to garner the attention of observers all over Europe, Galileo still could not stand among them.
‘During the entire time the comet was visible’, he reported later, ‘I was confined by illness to my bed. There I was often visited by friends. Discussions of the comets frequently occurred, during which I had occasion to voice some thoughts of mine which cast doubt upon the doctrines that have been previously held on this matter.’ In fact, Galileo saw only one important comet his whole life – the big bright one of 1577, in his youth – and never did figure out what these objects really were.
Most of Galileo’s contemporaries feared comets as evil omens. (Indeed the three 1618 examples were presently seen, with hindsight, as heralds of the Thirty Years’ War, which broke out in Bohemia the same year.) Aristotelian philosophers figured comets for atmospheric disturbances. The fact that comets came and went, changing their fuzzy-glow appearance all the while, automatically relegated them to the sublunar sphere between the Earth and the Moon, where they were thought to be ignited by friction of the spheres’ turning against the upper reaches of the air.
It may seem incredible that Galileo resisted the temptation to go outdoors in the autumn of 1618 long enough to view any one of the three comets, especially since he felt well enough to enter into intellectual discussions with visitors. But in fact the November night air held terrible danger for him, a man well past fifty now, who had spent most of the current year battling one malady after another. Moreover, as Galileo no doubt knew from his friends’ accounts, he would not have seen much even if he had risked his own study of these objects. A comet, or ‘hairy star’, retained its blurred contours despite the aid of the most powerful telescope.* Unlike the fixed stars that resolved into points of light when the telescope stripped them of their rays, or planets that turned to tiny globes, a comet could not be brought into sharp focus. And Galileo held back because he believed – in agreement for once with his Aristotelian contemporaries, though not for the same reasons – that comets belonged to the Earth’s atmosphere.
Galileo
