While investigating static that interfered with transatlantic radio telephone calls for Bell Laboratories, the engineer Karl Jansky built a rotating antenna in New Jersey. He found a steady hiss that rose and fell every 23 hours and 56 minutes, matching the rotation of the stars, and traced it to the direction of Sagittarius, the centre of the Galaxy. His announcement in 1933 launched radio astronomy, which later revealed pulsars, quasars and the cosmic microwave background. Few astronomers followed him at first, and the field grew mainly after the Second World War.
Before and after
- from 1933 to 1945The Holocaust
- 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
More in Science & technology
- 15 September 1917Launch of Forbes
- 1923Brønsted–Lowry acid–base theory
- 4 March 1936First flight of LZ 129 Hindenburg
- from c. 1940s to 1960sGreen Revolution
- October 1943Streptomycin, the first antibiotic that works against tuberculosis, is discovered
- 1944Avery, MacLeod and McCarty show that DNA carries genes
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.