ENGLAND’S FORGOTTEN GALILEO A VIEW ON THOMAS HARRIOT’S BALLISTIC PARABOLAS

Galileo’s insight into the parabolic shape of projectile trajectories is com-monly considered not only as having provided a major turning point in the history of ballistics, but also as having constituted a fundamental step towards the establishment of classical mechanics. In fact, from a modern perspective, the parabolic trajectory is closely associated with three of the most fundamental principles of classical mechanics, the law of inertia, the law of fall, and the superposition of motions without interference. Fig. 1: Construction of a projectile trajectory in classical mechanics. According to classical mechanics, the projectile trajectory results from a composition of two motions, an inertial motion along the line of the shot, and the accelerated motion of free fall vertically downwards. Given the knowledge of the laws governing these two fundamental kinds of motion, points on the trajectory can be geometrically constructed by considering th