Astroparticle physics is an interdisciplinary field embracing astronomy, astrophysics and particle physics. In a recent paper on this topic, Brigitte Falkenburg defended that only scientific realism can make sense of it and that realist beliefs constitute an indispensable methodological principle of research in this discipline. The aim of this work is to show that there exists an anti-realist alternative to this account, along the lines of what Bas van Fraassen showed in his famous book The Scientific Image. Problems and results (...) of astroparticle physics can be understood from an empiricist point of view too, namely that of van Fraassen’s constructive empiricism, which is a more modest and metaphysics-free alternative to scientific realism. Although constructive empiricism can make sense of science no worse than scientific realism does, van Fraassen’s goal is not to demonstrate that his stance is the only viable position, but just that it is not incoherent or proven false by his opponents. In this paper it will be shown that the constructive empiricist stance constitutes a legitimate alternative to scientific realism even when it gets to astroparticle physics and that it does indeed make sense of this new discipline, pace Falkenburg. (shrink)

Studying astroparticle physics sheds new light on scientific explanation and on the ways in which cosmology is empirically underdetermined or not. Astroparticle physics extends the empirical domain of cosmology from purely astronomical data to “multi-messenger astrophysics”, i.e., measurements of all kinds of cosmic rays including very high energetic gamma rays, neutrinos, and charged particles. My paper investigates the ways in which these measurements contribute to cosmology and compares them with philosophical views about scientific explanation, the relation between theory and data, (...) and scientific realism. The “standard models” of cosmology and particle physics lack of unified foundations. Both are “piecemeal physics” in Cartwright's sense, but contrary to her metaphysics of a “dappled world” the work in both fields of research aims at unification. Cosmology proceeds “top-down”, from models to data and from large scale to small-scale structures of the universe. Astroparticle physics proceeds “bottom-up”, from data taking to models and from subatomic particles to large-scale structures of the universe. In order to reconstruct the causal stories of cosmic rays and the nature of their sources, several pragmatic unifying strategies are employed. Standard views about scientific explanation and scientific realism do not cope with these “bottom-up” strategies and the way in which they contribute to cosmology. In addition it has to be noted that the shift to “multi-messenger astrophysics” transforms the relation between cosmological theory and astrophysical data in a mutually holistic way. (shrink)