Was dark matter first discovered by Fritz Zwicky or Vera Rubin?

It’s hard to believe, but the idea that the Universe was dominated not by normal matter but rather by dark matter — a novel form of non-interacting matter that’s completely distinct from protons, neutrons, and electrons — goes all the way back to 1933: nearly a full century ago. For decades, the overwhelming majority of the leading astronomers and physicists dismissed the idea as being ill-motivated and lacking sufficient evidence backing it, and it gained very little traction on both the theoretical and observational fronts throughout the 1930s, 1940s, 1950s, and 1960s. It was only with the n