The aim of the seminar is to discuss philosophical topics concerning quantum mechanics and to encourage a mutual collaboration between physicists and philosophers working at the Institute. The philosophical topics of the seminar may vary from metaphysical-oriented issues, such as the nature of the wave function and the meaning of decoherence, to more foundational issues, such as Bohm’s theory and quantum gravity.
In the field of the foundations of quantum mechanics, the physical meaning of the wave function has been the subject of intense debates over the last decade. One of the quantum theories defended in this field is Bohmian mechanics. Within the Bohmian community, the dominant viewpoint is the nomological interpretation of the wave function. It consists in the idea that the wave function does not represent a material object or a physical field, but is part of the law of nature governing the behavior of material entities. The primitive ontology approach sums this up by categorizing the wave function as a nomological entity. To give a more concrete meaning to this abstract notion, the wave function is often compared to the classical Hamiltonian, which, like the wave function, is a high-dimensional field whose gradient generates the motion of particles. However, unlike the wave function, the classical Hamiltonian is not the solution of a differential equation. In this article, we are going to argue that the action function, or Hamilton’s principal function, constitutes a better classical analogue to the wave function, as it provides us with an example of a dynamic nomological entity. Based on a clear distinction between laws of nature and nomological entities, this analogy can help to address some of the common criticisms levelled at the nomological interpretation, without resorting to the interesting, yet hypothetical, Wheeler-de Witt equation.
