Niels Martens joins the Vossius Center for one month in February 2020 and again for two months in August 2020 as a Research Fellow with the project "History and philosophy of the distinction between (dark) matter & (modified) spacetime".
According to Democritus’ atomism, everything in our universe is fundamentally either space (void) or matter (atoms). This strict conceptual dichotomy between space(time) and matter has reigned supreme ever since Newton revived it. Three years ago I embarked upon a historical and philosophical research programme that critically evaluates the tenability of the claims that these two categories are the most fundamental ontological and conceptual categories and that every object in our universe falls neatly into exactly one of these categories. The aim is to write a comprehensive book on this topic, integrating interdisciplinary perspectives from history, physics, philosophy and sociology, whilst covering case studies ranging from classical physics, through general relativity, black holes, spin-2 gravity, horror vacui, the dark matter vs modified gravity debate and dark energy, all the way to quantum gravity. Studying historical sources will be an important part of this project.
The main focus of my research is the more historical and sociological aspects of the dark matter communities, the modified gravity communities and their interaction, by engaging with Prof. Jeroen van Dongen and Jaco de Swart’s current projects on these issues. As their work has made clear, acceptance of the need for and existence of (a single unified concept of) dark matter by the various communities involved was much less straightforward and instantaneous as it is nowadays portrayed to be. This shines an interesting, relativizing light on the current situation, where the belief in dark matter is seen as an unquestionable truth by the majority community within physicsꟷdespite a prolonged period of failing to directly detect or produce dark matter particlesꟷleading to a conflicted relationship with the minority of modified gravity advocates (i.e. dark matter deniers). We organized a conference in February in Aachen that brought together 70 physicists, philosophers, historians and sociologists working on dark matter, modified gravity and the interface between the two camps. It became abundantly clear that the different communities have vastly different understandings of the concept of dark matter, and are almost unable to communicate across community boundaries. I would like to understand the historical-sociological development that lead to this rather unproductive situation. In particular, I intend to investigate this situation under the framework of Galison’s ‘trading zones’ꟷdifferent communities are able to collaborate and exchange results not, for instance, by being able to translate each other’s theories fully, but rather by creating an intermediate contact language, a creole. To what extent is/was there a trading zone between the dark matter and modified gravity communities (as well as between the theorists, experimentalists and instrument designers) during different periods over the last four decades? Are there ways of improving the communication and understanding between the various communities? Is the dark matter vs modified gravity debate a counter-example to Galison’s reconstruction of science, and do, eg., Kuhn’s paradigms provide a more apt description?
A secondary line of research would be to commence working on the black hole case study. Is a black hole spacetime, matter, both, or neither? There is a large variety of ways of understanding what a black hole is supposed to be, depending on the theoretical perspective adopted and the community one is surrounded by. For instance, general relativity seems to suggest that it is part of spacetime, whereas black hole thermodynamics coheres more with categorizing a black hole as matter. In this context an analysis in terms of Galison’s trading zones may again be enlightening.
Niels Martens is a Postdoctoral Researcher in Philosophy of Physics within the interdisciplinary research unit ‘Epistemology of the LHC’, located at the University of Bonn, Germany, in the Lichtenberg Group for History and Philosophy of Physics, and is associated with the Institute for Theoretical Particle Physics and Cosmology at RWTH Aachen University.