Vera Rubin, Discoverer of Dark Matter, Has Died

Vera Rubin, a pioneering astronomer who discovered dark matter, has died. She was 88. Her work in astronomy ushered in a revolution in how we saw the Universe. Dark matter is invisible, but it has mass, and affects the cosmos on a large scale. Rubin's work was studying galaxy rotation curves, literally how spiral galaxies spin. When she plotted her data, she found that the graphs of rotation speed versus distance from the center could not be explained using the standard model for galactic struct...