Jochen Büttner

Galileo's New Mechanics: Challenges Between Earth and Heaven

Most accounts in the history of science that deal with the ever-growing degree to which the cosmos was subjected to mechanisation in the 16th and 17th century until, to speak with Koyré, it eventually completely disappeared, are characterised by a particular biased preconception: according to this conception the mechanisation of the heavens in the period has to be understood as a systematic attempt to establish a foundation for the new Copernican world view. Consequently, with regard to Galileo's achievements, which beyond dispute represent an immense contribution to the process of the mechanisation of the heavens, scholars have primarily focused their attention on investigating the circumstances and motivations of his conversion to Copernicanism and have assessed his early attempts of an integration of cosmological issues with his new science of motion almost exclusively from such a perspective.

The contribution will discuss three sources documenting the earliest examples of Galileo's consideration which challenged the traditional separation and opposition of the physica coelestis and physica terrestris. I will attempt to show that Copernican issues played, if at all, a marginal role in these reflections. In all three cases it was rather the introduction of new challenges into the developing framework of mechanics that almost unavoidably lead to the expansion of mechanical arguments from the domain of the Earth to the domain of the heavens.

It can in fact be asked whether, in Galileo's time, the omnipresence of the prevailing Aristotelian natural philosophy in which terrestrial physics was an integral part of a global world view created boundary conditions that no attempt at a new mechanics could ignore. This factor together with the introduction of new mechanical arrangements and phenomena, the so called challenging objects of early modern science, may provide an explanation why the preconceived separation between the Heaven and the Earth was so persistently challenged in the early modern period, a process in which the search for arguments in favour of the Copernican world view turns out to be merely a particular facet.