Home > Joseph John Thomson

Thomson was born in 1856 near Manchester in England, of Scottish parentage. He studied engineering at Owen's College, Manchester, and moved on to Trinity College, Cambridge. In 1884 he became Cavendish Professor of Physics. In 1890 he married Rose Paget, and he had two children with her. One of his students was Ernest Rutherford, who would later succeed him in the post.

Influenced by the work of James Clerk Maxwell, and the discovery of the X-ray, he deduced that cathode rays (see cathode ray tube) existed of negatively charged particles, which he called "corpuscles", and which are now known as electrons. The electron had been posited earlier, by G. Johnstone Stoney, as a unit of charge in electrochemistry, but Thomson realised that it was also a subatomic particleIn physics, a subatomic particle is a particle smaller than an atom. These include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), as well as particles produced by ra, the first one to be discovered. His discovery was made known in 1897Events January 1 Brooklyn, New York merges with New York City. January 4 A British force is ambushed by Chief Ologbosheri, son-in-law of the Oba of Benin. This leads to a Punitive Expedition against Benin. February 2 The Pennsylvania state capitol is dest, and caused a sensation in scientific circles, eventually resulting in his being awarded a Nobel prizeList of Nobel Prize laureates in Physics from 1901 to the present day. 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s External links Official site (source for all citatio ( 1906Events January 8 Landslide in Haverstraw, New York kills 20 January 31 Earthquake in Ecuador (8. 6 in Richter scale) February 11 Pope Pius X publishes the encyclical Vehementer nos''. February 15 Representatives of the Labour Representation Committee in t). In one of the greatest ironies of modern physics his son George Paget ThomsonGeorge Paget Thomson ( 1892 1975), British physicist and son of Nobel Prize winning physicist J. After serving in the first world war Thomson followed in his father's footsteps working first at Cambridge and then Aberdeen and was himself awarded the Nobel later received the prize for proving that the electron was in fact a wave. (See wave-particle dualityIn physics, wave-particle duality holds that light and matter simultaneously exhibit properties of waves and of particles (or photons). This concept is a consequence of quantum mechanics. Fresnel, Maxwell, and Young In the early 1800s, the double-slit exp) Much of this work was done at the Cavendish LaboratoryThe Cavendish Laboratory is the Department of Physics of the University of Cambridge. The Department is itself part of the School of Physical Sciences. It was built in 1873 as a teaching laboratory. It was initially on the New Museums site off Free School.

Thomson's investigations into the action of electrostatic and magnetic fields on the nature of so called " anode raysCanal rays" were produced in experiments by a German scientist, Eugen Goldstein, in 1886. Goldstein used a gas discharge tube which had perforated cathodes. A "ray" was produced in the holes (canals) in the cathode and traveled in a direction opposite to" or "canal rays" would eventually result in the invention of the mass spectrometer (then called a parabola spectrograph) by Francis Aston, a tool which allows the determination of the mass-to-charge ratio of ions and which has since become an ubiquitous research tool in Chemistry.

Prior to the outbreak of World War I, he made another ground-breaking discovery: the isotope. In 1918, he became Master of Trinity College, Cambridge, where he remained till his death. He died in 1940 and is buried in Westminster Abbey, close to Isaac Newton.