Vera Rubin

Something wasn’t adding up.

The more Dr. Vera Rubin peered through her telescope, fixated on the spiral galaxies she was observing, the more she became aware of an unsettling discrepancy in her data. Galaxies were spinning at speeds that defied the conventional wisdom of the time.

You should be able to work out exactly how much mass is in a galaxy based on how fast the galaxy spins around its core, and vice versa. Gradually, Rubin’s methodical approach led her to a conclusion that shattered the world of cosmology: there was a bunch of mass missing that we couldn’t see.

This was 1963, and over the next few years, Rubin’s observations and conclusions became widely accepted. This “mystery of the missing mass” began to be described more succinctly as “dark matter.” That’s what we call it today.

Gaining Footing

Remembering her childhood, Rubin later said, “Even then I was more interested in the question than in the answer. I decided at an early age that we inhabit a very curious world.”

Born i…