The young mathematician had rapidly acquired the reputation that was necessary to gain such a position, but there were still higher positions at which he might aim. Galileo spent three years holding this post at the university of Pisa and during this time he wrote De Motu a series of essays on the theory of motion which he never published. It is likely that he never published this material because he was less than satisfied with it, and this is fair for despite containing some important steps forward, it also contained some incorrect ideas.
Noor matemaatik oli kiiresti omandanud maine, et oli vaja saada selline seisukoht, kuid oli siiski suurem seisukohti, millega ta võib eesmärk. Galileo veetis kolm aastat, kellel seda postitust Ülikooli Pisa ja selle aja jooksul kirjutas ta De Motu seeria esseesid teooriat resolutsiooni, milles ta ei avaldanud. On tõenäoline, et ta ei avaldanud see materjal, sest ta oli väiksem kui rahul ja see on õiglane, kuigi sisaldab mitmeid olulisi samme edasi, see sisaldas ka mõned valed ideid.