This article compares treatments of the Stern–Gerlach experiment across different physical theories, building up to a novel analysis of electron spin measurement in the context of classical Dirac field theory. Modeling the electron as a classical rigid body or point particle, we can explain why the entire electron is always found at just one location on the detector but we cannot explain why there are only two locations where the electron is ever found. Using non-relativistic or relativistic quantum mechanics, we (...) can explain both uniqueness and discreteness. Moving to more fundamental physics, both features can be explained within a quantum theory of the Dirac field. In a classical theory of the Dirac field, the rotating charge of the electron can split into two pieces that each hit the detector at a different location. In this classical context, we can explain a feature of electron spin that is often described as distinctively quantum but we cannot explain another feature that could be explained within any of the other theories. (shrink)

What is the relation between material hermeneutics, bodies, perception and materials? In this article, I shall argue cultural learning processes tie them together. Three aspects of learning can be identified in cultural learning processes. First, all learning is tied to cultural practices. Second, all learning in cultural practice entangle humans’ ability to recognize a material world conceptually, and finally the boundaries of objects, the object we perceive, are set by shifting material-conceptual entanglements. All these aspects are important for material hermeneutics (...) in a technoculture. Postphenomenology has expanded the connection between hermeneutics and phenomenology by focusing on studies of how perception, bodies, materials, the sensual realm and hermeneutics are entwined when we perceive the world through technologies. Following Don Ihde, hermeneutics expands beyond interpretation of texts in the humanities. We can interpret materials as for instance animal bones to make new sense of the Bible. New technologies have expanded material hermeneutics, when we can ‘look’ into bodies and ‘perceive’ below surfaces. Interpretation via such tools in a technoculture, both limit and extend our hermeneutic horizons in the humanities as well as in the natural sciences. Furthermore, from the perspective of cultural learning processes, material hermeneutics in the human and natural sciences depend on more than mediating instruments. Material hermeneutics also involve the material cultural environments of scientific apparatuses and the scientists’ processes of learning in cultural practice. This changes the focus from relations in postphenomenology to processes of relations. (shrink)

What Remains Is What Should Remain: Using Estates to Construct Biographies. Estates play a major role in historical research, especially biographic research, for they supplement the official writings surrounding the individual view of a historical figure. But they nonetheless reflect only a small part of the scientific and private activities of a researcher. Moreover, before being handed over to an archive, they are also often filtered by the researchers themselves, by family members, and/or by successors to the historical figure’s post. (...) The history of an estate is thus of great importance to research. With an eye to the estates of natural scientists, the present text uses a concept of estates that includes not only the surviving texts but also artifacts with which the scientists worked. The focus will be on three physicists – Ernst Mach, Walther Gerlach, and Philipp Lenard – in order to investigate the significance of these objects for their respective biographies and for the history of physics. (shrink)