Badoer was one of the correspondents of Paolo Sarpi in Venice, who towards the end of 1608 was making enquiries about the invention in the Netherlands of the telescope. Badoer wrote back in Spring 1609 from Paris to Sarpi with news of the commercial telescopes then being sold; it is said that Galileo heard of the new product via this route, around July 1609. He mentioned Badoer as his source in Sidereus Nuncius.
Religion and diplomacy
By upbringing Badoer was a Huguenot; he became a Catholic convert through the Jesuit Pierre Coton, at some point in the period 1599 to 1603, and by this connection became a diplomat in the service of Henry IV of France. One mission was to Cleves in 1609, at the time of the Jülich-Cleves War. Sarpi, who in 1609 wrote to Badoer in confiding terms, broke with him around 1610: he then described Badoer as an atheist, and Francesco Castrino of Sarpi's network wrote obscene poems about him (Badoer was a reputed homosexual).
- The surname is spelled also Badouère, Badouer, Badovere, and Badoire; the forename is given as Jacques.
- Galileo; William R. Shea; Mark Davie (9 February 2012). Selected Writings. Oxford University Press. p. 397. ISBN 978-0-19-958369-0. Retrieved 25 July 2012.
- (in Italian) treccani.it, Badoer (Badouère nella forma francesizzata), Giacomo.
- John Michael Lewis (1 April 2006). Galileo in France: French Reactions to the Theories and Trial of Galileo. Peter Lang. p. 91. ISBN 978-0-8204-5768-0. Retrieved 25 July 2012.
- Mario Biagioli (15 July 2007). Galileo's Instruments of Credit: Telescopes, Images, Secrecy. University of Chicago Press. p. 84. ISBN 978-0-226-04562-7. Retrieved 25 July 2012.
- Stillman Drake; Noel M. Swerdlow; Trevor Harvey Levere (1999). Essays on Galileo and the History and Philosophy of Science. University of Toronto Press. p. 42. ISBN 978-0-8020-8165-0. Retrieved 25 July 2012.
- David Wootton, Paolo Sarpi: Between Renaissance and Enlightenment, pp. 128–131 and p. 139.