- Thomson , Sir Joseph John
- (1856–1940) British physicistThomson, who was born in Manchester, entered Owens College (later Manchester University) at the age of 14. After studying engineering and then the sciences, he won a scholarship to Trinity College, Cambridge University. He graduated in 1876 and remained a member of the college in various capacities for the rest of his life. After graduating he worked at the Cavendish Laboratory under John Rayleigh, whom he succeeded as Cavendish Professor of Experimental Physics in 1884. As professor, Thomson built up the Cavendish Laboratory as a great and primarily experimental research school. Thomson was succeeded as professor in 1919 by his student Ernest Rutherford.Thomson's most brilliant and famous scientific work was his investigations into cathode rays, in which he is considered to have discovered the electron. Using a highly evacuated discharge tube he calculated the velocity of the rays by balancing the opposing deflections caused by magnetic and electric fields. Knowing this velocity, and using a deflection from one of the fields, he was able to determine the ratio of electric charge (e) to mass (m) of the cathode rays. Thomson found that the ratio e/mwas the same irrespective of the type of gas in the tube and the metal of the cathode, and was about a thousand times smaller than the value already obtained for hydrogen ions in the electrolysis of liquids. He later measured the charge of electricity carried by various negative ions and found it to be the same in gaseous discharge as in electrolysis. He thus finally established that cathode rays were negatively charged particles, fundamental to matter, and much smaller than the smallest atoms known. This opened up the way for new concepts of the atom and for the study of subatomic particles. Thomson announced his discovery of a body smaller than the hydrogen atom in April 1897.His later researches included studies of Eugen Goldstein's canal rays, which he named positive rays. These studies gave a new method (1912) of separating atoms and molecules by deflecting positive rays in magnetic and electric fields. Ions of the same charge-to-mass ratio form a parabola on a photographic plate. Using this arrangement, Thomson first identified the isotope neon–22. This work was taken up by Francis W. Aston, who later developed the mass spectrograph.Thomson's treatises were widely used in British universities. HisConduction of Electricity Through Gases (1903) describes the work of his great days at the Cavendish; his autobiography,Recollections and Reflections, was published in 1936. He was awarded the 1906 Nobel Prize for physics for his work on the conduction of electricity through gases, and was knighted in 1908.
Scientists. Academic. 2011.
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Thomson,Sir Joseph John — Thomson, Sir Joseph John. 1856 1940. British physicist. He won a 1906 Nobel Prize for investigating the electrical conductivity of gases. * * * … Universalium
Thomson, sir Joseph John — ► (1856 1940) Físico británico. Fue premio Nobel de Física en 1906, por sus trabajos sobre el paso de la electricidad a través de los gases … Enciclopedia Universal
Sir Joseph John Thomson — noun English physicist who experimented with the conduction of electricity through gases and who discovered the electron and determined its charge and mass (1856 1940) • Syn: ↑Thomson, ↑Joseph John Thomson • Instance Hypernyms: ↑physicist … Useful english dictionary
Joseph John Thomson — noun English physicist who experimented with the conduction of electricity through gases and who discovered the electron and determined its charge and mass (1856 1940) • Syn: ↑Thomson, ↑Sir Joseph John Thomson • Instance Hypernyms: ↑physicist … Useful english dictionary
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Joseph John Thomson — Sir Joseph John Thomson (18. december 1856 30 August 1940), også kendt under initialerne JJ, var en engelsk fysiker, som opdagede elektronen i 1897. Han fik nobelprisen i fysik i 1906. Thomson blev født i 1856 nær Manchester, England af forældre… … Danske encyklopædi
Joseph John Thomson — Sir Joseph John Thomson (n. Cheetham Hill, Reino Unido, 18 de diciembre de 1856 † Cambridge, 30 de agosto de 1940). Físico británico, premio Nobel de Física en 1906. Estudió en el Owens College (hoy parte de la Universidad de Manchester) y en el… … Enciclopedia Universal
Joseph John Thomson — Pour les articles homonymes, voir Joseph Thomson. Joseph John Thomson Gravure sur acier de Joseph John Thomson publié en 1896 Naissance … Wikipédia en Français
Thomson, Sir J.J. — ▪ British physicist Introduction in full Sir Joseph John Thomson born Dec. 18, 1856, Cheetham Hill, near Manchester, Eng. died Aug. 30, 1940, Cambridge, Cambridgeshire English physicist who helped revolutionize the knowledge of atomic… … Universalium
Joseph John Thomson — Nacimiento 18 de diciembre de 1856 Cheetham Hill … Wikipedia Español