**Giuseppe Biancani** was an Italian Jesuit astronomer and mathematician who made observations of the moon and planets with the newly invented telescope.

- Galileo had been appointed professor of mathematics at the University of Padua, the university of the Republic of Venice, in 1592 and Biancani became acquainted with him during his years in Padua.
- This friendship was an important one for Biancani, who later found himself in a difficult position pulled between the views of his Jesuit order and the revolutionary new ideas being argued by Galileo.
- It is also worth recounting the tensions in Padua during the years that Biancani studied there.
- Much of the argument, which continued during the years that Biancani studied there, was centred around the teachings of Aristotle; the Jesuit teachers were accused of not teaching directly from Aristotle but rather using modern texts.
- Clearly this influenced Biancani who, a few years later in 1615, published a text Aristotelis loca mathematica ex universis ipsius operibus collecta et explicata in which he treated the mathematical parts of Aristotle's writings.
- In the early 1600s Biancani, having completed the long training period for the Jesuit order, went to the Jesuit College in Parma where he taught mathematics for his whole career.
- We have quoted above from Biancani concerning his high regard for Galileo.
- Galileo suspected that Biancani was the author of the report and letters were exchanged in which Biancani dissociated himself from any insult towards Galileo saying that he was sorry if he had been offended but, nevertheless, pointing out that he did believe that the moon was perfectly smooth.
- Biancani, however, defended his fellow Jesuit Scheiner.
- We noted above that Biancani published Aristotelis loca mathematica in 1615.
- Before the work could be published, Biancani had to remove the description of Galileo's work on floating bodies, and replace it with a simple reference indicating where Galileo's theory could be found.
- the dedication is followed by an address to the reader wherein Biancani, in a rhetorical tirade, bemoans the wretched state to which mathematics has sunk and calls for its revitalisation.
- Biancani attached to this work his mathematical chronology De Mathematicarum natura dissertatio una cum clarorum mathematicorum chronologia.
- As to the chronology errors, let us give some examples: Thabit ibn Qurra (836-901) whom Biancani gives as a 13th century scholar, Roger Bacon (1214-1292) who is given as a 14th century scholar, and Leonardo Pisano (Fibonacci) (1170-1250) who is put in the 15th century.
- It is not entirely clear where Biancani stood on the question of a geocentric or heliocentric system.
- In it Biancani presented details of the work of Nicolaus Copernicus, Tycho Brahe, Johannes Kepler, and Galileo.
- The last two of these have a posthumous publication of Biancani's attached, namely Novum instrumentum ad horologia describenda.
- During his final four years teaching at Parma, from 1620 to 1624, Biancani taught Giovanni Battista Riccioli who was one of his students.
- Riccioli makes it clear what a strong positive influence Biancani had on him.
- Finally, we note that Biancani's writings on history, poetry and classical Greek and Latin have not survived.

Born 8 March 1566, Bologna, Papal States (now Italy). Died 7 June 1624, Parma, Duchy of Parma and Piacenza (now Italy).

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Astronomy, Origin Italy

**Oâ€™Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive