Galileo's Handwritten Notes Discovered in a Medieval Astronomy Text

Historian Ivan Malara discovered Galileo's handwritten notes in a 16th-century book, a reprint of Ptolemy's work on the geocentric universe. The notes, likely from around 1590, offer insights into Galileo's intellectual journey before his telescopic discoveries. Galileo's annotations show a deep engagement with Ptolemy's arguments, analyzing and critiquing them critically. Malara suggests that Galileo's understanding of Ptolemy's logic ultimately led him to the heliocentric model.