MOND: Crooked star clusters may be a sign that Einstein’s gravity is wrong

Astronomers have found an unexpected asymmetry in stars escaping from their clusters, and it cannot be easily explained by our standard theories of gravity

By Leah Crane

A strange effect in clusters of stars is bringing our ideas of how gravity works into question. These star clusters seem to have an unexpected asymmetry, which fits better under an alternate theory of gravity called modified Newtonian dynamics (MOND) than under Albert Einstein’s widely accepted theories.

Clusters of stars typically look a bit like a two-armed pinwheel with opposing tails, each formed when stars bouncing around within the cluster …