Spinning out a solution (Image: LSST)

Editorial: Bringing dark matter down to Earth

A SPINNING disc may be all that is needed to overturn Newton’s second law of motion – and potentially remove the need for dark matter.

The second law states that a force is proportional to an object’s mass and its acceleration. But since the 1980s, some physicists have eyed the law with suspicion, arguing that subtle changes to it at extremely small accelerations could explain the observed motion of stars in galaxies.

Stars move at speeds that suggest that galaxies have far more mass than is visible, which …