Vera Rubin and the Invisible Universe

In the 1970s, astronomer Vera Rubin did something that quietly broke physics: she measured how fast stars orbit the center of galaxies, and the numbers didn't add up. Stars at the outer edges of spiral galaxies were moving far too fast — faster than they should if the only gravitational force acting on them came from visible matter. Something else had to be there. Something massive, spread throughout the galaxy, and completely invisible. That something is now called dark matter, and its discovery changed cosmology forever. Rubin didn't get a Nobel Prize for it.

Rubin began her scientific life in the 1940s, when women were openly discouraged from pursuing physics and astronomy. Princeton's graduate astronomy program didn't admit women when she applied. She went to Cornell instead, then Georgetown,  ...