Lia Den Daas

The measurement problem of quantum theory has troubled the minds of physicists and philosophers for decades. This paper will discuss a relatively new attempt at resolving the issue, known as the mechanism of the “flea”, as put forward by Landsman and Reuvers in [13] and by Landsman in [12]. This paper first reviews the formalism of algebraic quantum theory. Chapter 3 then contains the greatest conceptual work, given by a novel understanding of the measurement problem. In this context, a small, asymmetric perturbation that arises from the environment is postulated, as described in chapter 4. This “flea” perturbation provides the symmetry breaking required for a classical state to emerge from a quantum system, thereby bringing us one step closer to a possible solution of the measurement problem. Chapter 5 hopes to offer an evaluation of the flea mechanism. These comments focus on the limitations of the models considered, as well as the nature of the flea perturbation. In particular, the challenges in attempting to recover the Born rule are discussed. This discussion is informed by the work of Van Heugten and Wolters in [22]. Finally, the conclusion contains some general reflections on the flea proposal, portraying it as the start of a new way of making the idea of a wave function collapse mathematically precise.