From Dante's Moonspots to Galileo's Sunspots

The unscheduled astronomical event seems to have left the strangest of traces in the early modern era. At stake was a personnel problem: the wrong people may well have been the first to witness the emergence of new stars, meteors, and large sunspots in the late sixteenth and early seventeenth centuries, and the right people were often enough without adequate explanation of these phenomena. Popular reaction to these occurrences is, and will doubtless remain, almost wholly lost to us, but a persistent doubling occurs at the site of the intellectual exchanges concerning them. A factitious tone, often established through the comparatively low registers of dialogue, dialect, and reported speech, maintained or created social and intellectual distance between discourses otherwise lacking sufficient distinction, and generated the impression of a steady evolution in scientific representation. Moreover, if the rapid development of a research-oriented natural philosophy in the early modern period depended upon the unprecedented combination of a crude and relatively unsystematic empiricism with improved instrumentation and an increasing reliance on quantification, it is plausible that the frequent inclusion of the pseudo-popular perspective in descriptions of puzzling celestial events signaled at once an awareness of the importance of the empirical view, and a self-conscious recognition of its shortcomings.¹

Fictionalized low- and middle-brow views of the sunspots of 1611-1613, the focal point of this essay, are perhaps the most plentiful instance of this sort of ventriloquizing. The invention of the Dutch telescope in the fall of 1608 and the publication of Galileo Galilei's Starry Messenger in the spring of 1610 had dramatically increased public interest in the heavens, but the relative scarcity of powerful instruments, the optical limitations of even the best of such devices, and the extraordinary lack of consensus concerning the interpretation of this abundant new information naturally contributed to the impression of a cacophonous exchange.² This essay will argue that while the era of solar exploration was characterized by the conventional deployment of the unlettered observer of celestial phenomena, Dante's depiction of such stratified knowledge concerning moonspots three hundred years earlier was also an important rhetorical resource for the most celebrated discussion, Galileo's Letters on the Sunspots.

The sudden emergence of a new star in the fall of 1604 can be regarded as a dress-rehearsal of sorts, for here the unlettered sky-watcher frequently made cameo appearances in descriptions of the supernova. "There's been a lot of whispering here about the new star," the Jesuit astronomer Christoph Clavius wrote in December 1604 to Galileo, but he relayed no particulars of the murmurs that allegedly engulfed Rome. He added instead that "we [at the Collegio Romano] have located it in the 17th degree of Sagittarius, with a northerly latitude of 1½ degrees," as if to insist upon a division of labor between those many whose initial notice of the new star emerged only as undifferentiated and undisclosed whispers, and those few who had eventually calculated its place with precision in the heavens. The Neapolitan natural philosopher and cleric Giovanni di Guevara, who had observed the new star in timely fashion but had mistaken it for Jupiter, likewise alluded to this basic trajectory of information in a letter to Giovanni Antonio Magini, one of Italy's most distinguished astronomers. News of the bright flare, in this account, underwent refinement from its emergence in early anonymous rumors about a comet, to repetition and occasional reformulation through identifiable intermediaries, and finally to eventual presentation to his erudite addressee:

Two nights later, upon asking someone who was coming from Florence what the news was from there, I was told, "They say that you can see the comet." And when I asked him, "What do you know about it?" he said, "passing through Florence on the Ponte Vecchio around two hours after sunset, I saw a great mass of many people, and asking what it was, they said that the crowd saw a comet." When I heard this, I finally saw that the star couldn't be Jupiter, and since I knew that there was no fixed star...