2000 HSS/PSA Program 1 - History of Science Society

HSS Abstracts
or correction a posteriori. This ideal created a paradoxical situation in which
the experimenter wished to control every single aspect of experimentation,
but at the same time aimed at complete self-effacement, considering himself
the ultimate source of all disturbances: nature dictated the course of
investigation and enslaved the experimenter. Regnault’s ideal was an aseptic
experiment, free of human contamination, in which the scientist assumed only
the role of catalyst, letting nature perform without interference. Given that
contemporaries of the 1840s considered Regnault to be Europe’s most
outstanding experimentalist, Regnault’s relentless pursuit to provide a basis
for objective knowledge in experimentation and to make nature speak
unambiguously characterise the (short-lived) hopes for absolute certainty of a
whole generation of experimentalists.
Sven Dupre Ghent University
Galileo, Optics and the Pinelli Circle
Beside Galileo’s training in perspective with Ostilio Ricci, early in his career,
as shown by Settle, and the scarce evidence offered by the books on optics
present in Galileo’s library, as shown by Favaro, little is known about the
immediate context of Galileo’s optics before he began improving the Dutch
telescope in 1609. This paper will propose a study of the texts and knowledge
of optics circulating in the circle of Gian Vincenzo Pinelli, a patron and avid
book and manuscript collector, Galileo became involved with from his early
days in Padua during the last decade of the sixteenth century. Among many
other things, Pinelli owned the unpublished manuscripts, consisting of lecture
notes and drafts of book chapters, on optics of Ettore Ausonio and Giuseppe
Moleto, the latter a professor of mathematics at the university of Padua and a
student of Maurolico, and the first a mathematician and physician from Venice.
That Pinelli took an interest in optics, is shown, on the one hand, by his
collection of mathematical instruments, and, on the other, by his own copying
of notes of Moleto and his annotations to the “Trattato della Pittura” of
Leonardo. However, also Galileo, who would have had access to Pinelli’s
library, was attracted by the wealth of optical information present in this library,
as is shown by his copying of Ausonio’s “Theorica speculi concavi sphaerici”
. By presenting the optics circulating in the Pinelli circle from hitherto unstudied
manuscripts, this paper will try to uncover the immediate optical context at
the end of the sixteenth century from which Galileo emerged. Finally, this
paper will try to establish to what extent the optics circulating in Galileo’s
information network at this particular moment in his career might have been
useful to his own optical work.
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