Joseph John Thomson died on 30 August 1940 in Cambridge, aged 83. A British physicist, Thomson discovered the electron in 1897 through experiments with cathode rays, showing that atoms are not indivisible but contain much smaller negatively charged particles. For this work he received the Nobel Prize in Physics in 1906. He later developed early forms of mass spectrometry and proposed the so-called plum pudding model of the atom. Long associated with the Cavendish Laboratory in Cambridge, he served as its director and as Master of Trinity College, and several of his students and even his own son, George Paget Thomson, also won Nobel Prizes.
Before and after
- from 14 July 1940 to 15 July 1940Operation Ambassador
- 19 July 1940Battle of Cape Spada
- from 21 July 1940 to 20 August 1991Estonian Soviet Socialist Republic
- 21 August 1940Death of Leon Trotsky
- 30 August 1940Death of Joseph John Thomson
- from 7 September 1940 to 21 May 1941The Blitz
- from 9 September 1940 to 16 September 1940Italian invasion of Egypt
- 12 September 1940Lascaux
- 20 September 1940Birth of Tarō Asō
More in Science & technology
- 15 September 1917Launch of Forbes
- 11 January 1922Insulin is first used to treat diabetes
- 1927Hubble–Lemaître law
- 1936Alan Turing defines the universal machine
- from 1939 to 1946Manhattan Project
- from c. 1940s to 1960sGreen Revolution
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.