[Encyclios]

History of ballistics

The mathematical study of shooting and therefore the birth of ballistics as a science can be traced back to the work of the Brescian N. Tartaglia (1499-1557), later taken up and developed by countless researchers, including G. Galilei and I. Newton.

The trajectory was originally considered linear, consisting of two straight segments, until Tartaglia demonstrated the curvature. Galileo later established that the trajectory is a parabola, limiting himself to the theoretical study of the function. Resuming Galileo’s work, Newton demonstrated (1723) that, although the trajectory in vacuum is a parabola, in air is a paraboloid curve with the descending line shorter than the ascending line and tending to the vertical.

This is due to the resistance offered by the air, which he proved to be directly proportional to the square of the velocity of the projectile, the density of air and the square of the caliber. This theory proved to be correct for subsonic velocities, around 250 m/s, while at higher velocities there are perturbations of the trajectory due to compression and rarefaction waves.

Newton’s statement must therefore be modified, replacing the square of the velocity with a resistant function, dependent on the speed itself. For the empirical study of ballistics and for the verification of theories, it was necessary to determine with sufficient accuracy the velocity of projectiles. This was made possible by Benjamin Robins, author of Principles of Gunnery, who invented the ballistic pendulum (1742). Important contributions to ballistic studies are due to Italians, especially Cavalli, Siacci and Bianchi.