Science progresses best when observations force us to alter our preconceptions.

Vera Rubin (1928 CE-2016 CE), Vera Florence Cooper Rubin was an American astronomer who pioneered work on galaxy rotation rates.[1][2] She uncovered the discrepancy between the predicted and observed angular motion of galaxies by studying galactic rotation curves. Identifying the galaxy rotation problem, her work provided some of the first evidence for the existence of dark matter.