Observations, Simulations, and Reasoning in Astrophysics

Abstract

Astrophysics faces methodological challenges as a result of being a predominantly observation-based science without access to traditional experiments. In light of these challenges, astrophysicists frequently rely on computer simulations. Using collisional ring galaxies as a case study, I argue that computer simulations play three roles in reasoning in astrophysics: (1) hypothesis testing, (2) exploring possibility space, and (3) amplifying observations.

Nested modalities in astrophysical modeling

“…See, e.g., the detailed investigation on the relation between models and simulations proposed by Winsberg (2018). A recent philosophical discussion of the role of computer simulations in astrophysics is provided by Jacquart (2020).…”

“…In fact, the functions and meaning of modeling and simulations in astrophysics have been objects of extensive philosophical study, especially in the last decade (e.g., Vanderburgh, 2003Vanderburgh, , 2014Anderl, 2018;Massimi, 2018;Smeenk & Gallagher, 2020;Gueguen, 2020;Jacquart, 2020Jacquart, , 2021. Here, we take a slightly different direction with respect to this literature, by considering the issue of astrophysical modeling in the framework of the current debate on modal modeling in science.…”

Excavation in the Sky: Historical Inference in Astronomy

“…Beyond this, even when the interest does not lie in the reconstruction of token events but in finding long-term regularities, many studies are of a historical nature. Our observation is only a “snapshot” of the cosmic processes that last for billions of years (Jacquart 2022). As it is unlikely that we could observe those processes or test a prediction in the far future, the relatively more accessible route is to observe fossils of such processes and make inferences backward.…”

Observations, Experiments, and Arguments for Epistemic Superiority in Scientific Methodology

“…One could argue that if it were possible to perform experiments that are in effect impracticable, then scientists would have access to more, better data. To borrow the case that Jacquart (2020) discusses, if astrophysicists could physically create head-on collisions between actual compact galaxies and disk galaxies under various conditions, they might learn more about the formation and evolution of ring galaxies than they can without physically smashing galaxies into one another. Performing physically impossible experiments would deliver more results than mere observation, thereby making experiment epistemically superior to observation, in principle.…”