An attempt to do without dark matter

The discrepancy between dynamical mass measures of objects such as galaxies and the observed distribution of luminous matter in the universe is typically explained by invoking an unseen "dark matter" component. Dark matter must necessarily be nonbaryonic. We introduce a simple hypothesis to do away with the necessity for dark matter by introducing an additional nongravitational force coupled to baryon number as a charge. We compare this hypothesis to Milgrom's modified Newtonian dynamics. The model ultimately fails when confronted with observation, but it fails in an interesting way.