169 years ago today, December 18, 1856 (November 21, 1856 in the lunar calendar), British physicist Joseph Thomson was born. Joseph John Thomson Joseph John Thomson was born on December 18, 1856 in a Scottish family near Manchester, England. He studied engineering at Owen College in Manchester and moved to Trinity College, Cambridge. In 1884 he became Cavendish Professor of Physics and Director of the Cavendish Laboratory. In 1890 he married Ruth Paggett and raised two children. One of his students was Ernest Rutherford, who succeeded Thomson as Cavendish Professor of Physics in 1919. Influenced by the work of James Clark Maxwell and the discovery of X-rays, he deduced that cathode rays (see cathode ray tubes) exist in negatively charged particles, which he called "particulates," which are now understood as electrons. The electron was once proposed by Johnstone Stoney as a unit of charge in electrochemistry, but Thomson realized that electrons are also subatomic particles, which was the first time it was discovered. His discovery became known in 1897 and caused a sensation in scientific circles, and was eventually awarded the Nobel Prize in Physics in 1906. Dramatically, his son, G. P. Thomson, was later awarded the Nobel Prize in Physics for confirming that electrons are waves. (See wave-particle duality). Comment: Discoverer of the electron and won the 1906 Nobel Prize in Physics ~