Diagramm, Experiment und die Anschaulichkeit von Theorie : zur Schematisierung der Bewegung bei Galileo Galilei

Abstract

How and where do relationships arise that can be rendered diagramma- tically? Do they emerge through the process of human reasoning or through the act of drawing on surface? Or do they unfold in the dynamic processes at play in observable reality? The following article argues that the latter is the case, making recourse to the philosophy of Charles Sanders Peirce. As a case study, it explores Galileo Galilei’s investigation of free-fall motion and examines both printed texts and manuscripts in order to understand how Galilei arrived at his conclusions. While the published diagrams present his results in graphic traditions that date back to the 14th century, Galilei’s handwritten sketches and notes demonstrate the difficult process of hypothesis formation. In these documents we can observe Galilei grappling with adapting the forms of older diagrammatical notation to his experiments. Through close observation of the phenomena in front of him, Galileo tries to comprehend clearly which parameters of motion can be measured and correlated on the inclined plane.