Galileo Galilei and Motion A Reconstruction of 50 Years of Experiments and Discoveries

Among the many books on Galileo Galilei only very few deal directly and in depth with his scientific accomplishments proper. This is one of them and among the correspondingly sparse literature the author of this work distinguishes himself by focusing on mechanics, in particular on the fundamental concept of motion and percussion - having performed crucial original experiments and in Galileo´s spirit. Indeed, while the author lets Galilei speak for himself when he explains his experiments and findings, he also makes full use of our present day knowledge of physics to make the reader better understand the perspective.

The result of this very fine understanding is an unsurpassingly authoritative account on some of the foundations of preclassical mechanics as laid down by the great Pisan scientist, widely regarded as the first experimental physicist in the modern sense.

This book will not only be an indispensable source of reference for historians of sciences but appeal to anyone interested in the foundations of experimental physics in general and of mechanics in particular.

Problems of chronology.- Around 1590: The dynamics of the De motu.- Le Mecaniche (1592–1600).- 1592–1610: “The best eighteen years of my life”.- 1602: The theorem of chords and the isochronicity of pendulums. The letter to Guidobaldo del Monte.- Before 1604: The law for falling bodies. Experimental results.- Folio 107v: The experimental confirmation of the law of motion.- Why “100 braccia in 5 seconds”?.- Before 1607: Parabolic trajectories.- Before 1610: The velocity acquired in descent is proportional to the square root of the height.- Before 1610: Launching from the inclined plane without a straightener.- The time taken to descend along inclined planes of equal height and the theorem of final velocity.- Another comparison between two motions: free fall and descent along a plane. Difficulties due to the rolling of the sphere.- Before 1606: Experiments on a ship in uniform motion. Long before 1623: Galileo’s principle of relativity.- The laws of motion: Galileo announces them in the Dialogo (1632) and presents them in the Discorsi (1638).- Before 1610: The constant-flow chronograph.- Galileo overcame the difficulty due to rolling by carrying out experiments with a new machine.- The conception of Galilei’s machine: The “vertical plane”.- A description of Galilei’s machine and of the experiments that can be carried out on it.- Marin Mersenne: A man who “wants to turn everything topsy-turvy”.- Conclusion.