144 Gama, Vasco da cation, which in all probability he himself had licensed, that the dull-witted Simplicio was a satire of him Urban reacted to Galileo’s ridicule by suppressing the Dialogue and establishing a commission to investigate the whole matter After reading the commission’s report, Urban referred the Galileo case to the Roman Inquisition The Inquisition summoned Galileo to Rome in the winter of 1632–33, a savage requirement to impose on an old man in ill health during a plague epidemic On his arrival in Rome in February, he was imprisoned Negotiations between Galileo and the inquisitors, who threatened torture, produced a public confession On June 22, 1633, he was condemned to house arrest and the recitation of penitential psalms He spent his arrest first in Rome, and from the end of 1633 to his death, at his own house outside Florence See also Copernicus, Nicolaus; Descartes, René; scientific revolution Galileo offering his telescope to three women and pointing to the heavens—site of his astronomical discoveries Further reading: Biagioli, Mario Galileo, Courtier: The Practice of Science in the Culture of Absolutism Chicago: University of Chicago Press, 1993; Drake, Stillman Galileo at Work Chicago: University of Chicago Press, 1978; Geymonat, Ludovico Galileo Galilei Stillman, Drake, trans New York: McGraw-Hill, 1965; Langford, Jerome J Galileo, Science and the Church Ann Arbor: University of Michigan Press, 1966; Shea, William R Galileo’s Intellectual Revolution London: Macmillan, 1972; Westfall, Richard S Essays on the Trial of Galileo Vatican City: Vatican Observatory, 1989 William E Burns Despite his enormous importance in the development of astronomy, Galileo was not at all what the early modern period considered an astronomer He was not concerned with the precise observations and elaborate calculations necessary to predict the courses of the stars that absorbed the vast majority of the labor of working astronomers Galileo was more interested in making telescopic discoveries and establishing cosmological theory The most significant work he wrote on astronomy after The Starry Messenger (1610) was Dialogue on the Two Chief Systems of the World (1632) In this work, Galileo used the motion of the Earth to explain the tides Galileo’s trial and conviction have been interpreted in many ways by historians There were two dangers in Dialogue on the Two Chief Systems of the World One was its bold statement of support for the Copernican system The other as that the pope, Urban VIII (Maffeo Barberini), became convinced after the dialogue’s publi- Gama, Vasco da (1460?–1524) Portuguese explorer Vasco da Gama was a Portuguese explorer who discovered the sea route to India from Europe through the Cape of Good Hope It is believed that da Gama was born in Sines, Portugal, in approximately 1460 He received his first important appointment in 1497 when he was named commander of a four-ship expedition that was to continue the work started by Bartolomeu Dias, who had attempted to find a route from Europe to India via the Cape of Good Hope Dias’s expedition had only made it a short distance past the Cape of Good Hope Da Gama’s expedition set out from Lisbon on July 8, 1497 The ships passed the Canary Islands on July 15, but then became separated in a fog They were able to regroup on July 26 at the Cape Verde island of Santiago