The brilliant and prolific Dutch astronomer Jan Oort came to a similar conclusion about dark matter a year earlier than Zwicky. Oort recognized that the velocities of stars in our local galactic neighborhood were too high for their motion to be attributed solely to the gravitational influence of light-emitting matter. Oort too deduced that something was missing. He didn’t conjecture a new form of matter, however, but merely nonluminous ordinary stuff—a proposal that has since been rejected for several reasons
