The Capture of Spring: Hooke’s “Vibrative Pulse Communicated”

Abstract

In 1678, Robert Hooke published a treatise on his metaphysics of vibration. Lectures de Potentia Restitutiva or Of Spring contains not only experimental and geometrical demonstrations of the spring law (which mutated into Hooke’s law after his time), but also a principle at the heart of his dynamic matter theory – Congruity and Incongruity. Namely, that harmonious and discordant forces unify, shape and separate vibrating matter. This thesis reconstructs Hooke’s production of congruity and incongruity, and the spring law, analysing the inversions, reversals and paradoxes moulding his knowledge-making practices. I argue that artificial instruments and apparatuses capable of magnifying and measuring never-before-seen minute bodies and motions also made the creation of a novel geometry necessary. I attempt to show how Hooke addressed these challenges by reassessing and reconfiguring the role of traditional Euclidean geometry, and reformulating practical-geometrical definitions to create a geometry that could demonstrate the spring law. Specifically, I focus on Hooke’s studies of vibrating bodies and vibrations, and his practical geometry. By investigating Hooke’s studies within the context of his matter theory, I show that, in an epistemological inversion, Hooke used optical instruments to shift frames of reference from the microscopic to the celestial and vice versa for his knowledge production. Further, Hooke’s work is a cohesive whole centred on his studies of the similitudes between vibrating phenomena. Finally, his knowledge-making practices are a conflation of his predominant careers as an experimentalist and geometer. By constructing natural laws from physical reality, thereby implying that nature, artificial instruments, and laws such as the spring law are related, Hooke legitimised the application of instruments and mathematics to the study of nature. This process was far from straightforward or self-evident.