Benedetto Castelli

Benedetto Castelli (1578 to 1643), born Antonio Castelli, was an Italian mathematician who took the name Benedetto on entering the Benedictine Order in 1595. Born in Brescia, he studied at the University of Padua and later became an abbot at the Benedictine monastery of Monte Cassino. He was a long time friend and supporter of his teacher Galileo Galilei and a teacher to Galileo son, assisted Galileo study of sunspots and took part in the examination of the theories of Copernicus. He was appointed mathematician at the University of Pisa in place of Galileo and later taught at the University of Rome La Sapienza. In December 1610 he wrote to Galileo asking whether the phases of Venus could be seen through the new telescope. His students included Giovanni Alfonso Borelli, Evangelista Torricelli and Antonio Nardi. He published Mensuration of Running Water, an important work on fluids in motion, on hydraulics, and died in Rome.