Studying the Coma Cluster of galaxies, the Swiss astronomer Fritz Zwicky found that its galaxies moved so fast that the cluster should have flown apart unless it contained far more mass than the visible stars. He called the missing material 'dunkle Materie', dark matter. His idea was largely ignored until the 1970s, when Vera Rubin's studies of galaxy rotation curves showed the same effect in individual galaxies. Today astronomers believe dark matter makes up roughly a quarter of the universe, yet no one has identified what it is.
Before and after
- 1933Construction of Lacoste
- 1933Enabling Act of 1933
- 1933Construction of Heydar Aliyev International Airport
- 1933Karl Jansky detects radio waves from the Milky Way
- 1933Fritz Zwicky infers dark matter
- 5 January 1933Death of Calvin Coolidge
- 25 January 1933Birth of Corazon Aquino
- 30 January 1933Hitler becomes Chancellor of Germany
- 18 February 1933Birth of Yoko Ono
More in Universe & space
- 21 July 1914Discovery of Sinope
- 1920Discovery of the Hoba meteorite
- October 1923Hubble shows that Andromeda is a separate galaxy
- 1927Lemaitre proposes an expanding universe
- 6 July 1938Discovery of Lysithea
- 30 July 1938Discovery of Carme
The era
This moment belongs to the Modern era (1914 CE to 1945 CE), world wars and a changing world. You can also browse everything in the 20th century.