Dark Matter Realism

TL;DR

The paper argues for cautious scientific realism about dark matter due to significant uncertainties about its properties, comparing this stance to the evolving understanding of the concept of genes.

Contribution

It introduces a nuanced form of semantic anti-realism called 'not(-yet)-realism' applied to dark matter, emphasizing the need for caution amid underdetermination.

Findings

Dark matter's properties are highly uncertain.

The analogy with the historical concept of genes illustrates conceptual evolution.

A cautious stance on dark matter realism is advocated.

Abstract

According to the standard model of cosmology, LambdaCDM, the mass-energy budget of the current stage of the universe is not dominated by the luminous matter that we are familiar with, but instead by some form of dark matter (and dark energy). It is thus tempting to adopt scientific realism about dark matter. However, there are barely any constraints on the myriad of possible properties of this entity -- it is not even certain that it is a form of matter. In light of this underdetermination I advocate caution: we should not (yet) be dark matter realists. The "not(-yet)-realism" that I have in mind is different from Hacking's (1989) anti-realism, in that it is semantic rather than epistemological. It also differs from the semantic anti-realism of logical empiricism, in that it is naturalistic, such that it may only be temporary and does not automatically apply to all other unobservables (or even just to all other astronomical unobservables, as with Hacking's anti-realism). The argument is illustrated with the analogy of the much longer history of the concept of a gene, as the current state of the concept of dark matter resembles in some relevant ways that of the early concept of genes.