The clearly recognized innovation in Galileo’s work on free fall has been a stimulus and a challenge for the history and philosophy of science. This article will analyze the experimental and theoretical aspects of Galileo’s work on free fall. It draws on several authors’ results to justify the claim that the research model established by Galileo remains valid today (Sections 2 and 3). The article draws this parallel with current science by focusing on Galileo’s method, way of considering scientific instruments, and practice of confrontation between theory and experiments. The Galilean mode of investigation can be interpreted from a variety of possible philosophical perspectives: Section 3 examines how relevant the so-called constructivist a...