Zwicky infers unseen mass in Coma
Zwicky infers unseen mass in Coma
Overview
In 1933 Fritz Zwicky applied the virial theorem to radial velocities of galaxies in the Coma Cluster and found they moved far too fast for the luminous matter to hold the cluster together. He concluded that most of the cluster's mass was invisible — 'dunkle Materie', dark matter. Ignored for decades, the discrepancy returned forcefully with galaxy rotation curves in the 1970s and is now one of the defining problems of cosmology.