Sir Joseph John Thomson
Born	1856-12-18 Cheetham Hill, Manchester, UK
Died	30 August 1940 (aged 83) Cambridge, UK
Residence	United Kingdom
Nationality	United Kingdom
Field	Physicist
Institutions	University of Cambridge Princeton University Yale University
Alma mater	University of Manchester University of Cambridge
Academic advisor	John Strutt (Rayleigh) Edward John Routh
Notable students	Charles T. R. Wilson Ernest Rutherford Francis William Aston John Townsend Owen Richardson William Henry Bragg Harold A. Wilson H. Stanley Allen
Known for	Plum pudding model Discovery of electron Discovery of isotopes Invention of the mass spectrometer
Notable prizes	Nobel Prize for Physics (1906)
Religion	Anglican
Thomson is the father of Nobel laureate George Paget Thomson.

Sir Joseph John “J.J.” Thomson, OM, FRS (18 December 1856 – 30 August 1940) was a British physicist and Nobel laureate, credited for the discovery of the electron and of isotopes, and the invention of the mass spectrometer. He was awarded the 1906 Nobel Prize in Physics for the discovery of the electron. Portrait of J.J. Thomson, from Practical Physics, Millikan and Gale, 1920. ... 1856 was a leap year starting on Tuesday (see link for calendar). ... is the 352nd day of the year (353rd in leap years) in the Gregorian calendar. ... Cheetham Hill is a district of Manchester, England located approximately 2 miles to the north of Manchester city centre. ... This article is about the City of Manchester in England. ... is the 242nd day of the year (243rd in leap years) in the Gregorian calendar. ... Year 1940 (MCMXL) was a leap year starting on Monday (link will display the full 1940 calendar) of the Gregorian calendar. ... This article is about the city in England. ... Not to be confused with physician, a person who practices medicine. ... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the worlds most prestigious universities. ... Princeton University is a private coeducational research university located in Princeton, New Jersey. ... Yale redirects here. ... Affiliations Russell Group, EUA, N8 Group, NWUA, Worldwide Universities Network (WUN) Website http://www. ... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the worlds most prestigious universities. ... John William Strutt, 3rd Baron Rayleigh (12 November 1842 – 30 June 1919) was an English physicist who (with William Ramsay) discovered the element argon, an achievement that earned him the Nobel Prize for Physics in 1904. ... Image File history File links No higher resolution available. ... Edward John Routh (1831-1907) was a British mathematician, noted as the outstanding coach of students preparing for the Mathematical Tripos examination of the University of Cambridge in its heyday in the middle of the nineteenth century. ... Charles Thomson Rees Wilson (February 14, 1869 – November 15, 1959) was a Scottish physicist. ... Image File history File links No higher resolution available. ... Ernest Rutherford, 1st Baron Rutherford of Nelson OM PC FRS (30 August 1871 - 19 October 1937), widely referred to as Lord Rutherford, was a nuclear physicist who became known as the father of nuclear physics. ... Image File history File links No higher resolution available. ... Francis William Aston (born Harborne, Birmingham, September 1, 1877; died Cambridge, November 20, 1945) was a British chemist and physicist who won the 1922 Nobel Prize in Chemistry for his discovery, by means of his mass spectrograph, of isotopes, in a large number of non-radioactive elements, and for his... Image File history File links No higher resolution available. ... John Sealy Edward Townsend (June 7, 1868 - February 16, 1957) was a mathematical physicist who conducted various studies concerning the electrical conduction of gases (concerning the kinetics of electrons and ions) and directly measured the electrical charge. ... Owen Willans Richardson (down) Solvay conference 1927 Sir Owen Willans Richardson (April 26, 1879 - February 15, 1959) was a British physicist, a professor at Princeton University from 1906 to 1913, and a recipient of the Nobel Prize in Physics in 1928 for his work on the thermionic phenomenon and especially... Sir William Henry Bragg OM, Cantab, OKW (Westward, Cumbria, England July 2, 1862 – March 10, 1942) was an English physicist and chemist, educated at King Williams College, Isle of Man, and Trinity College, Cambridge. ... Image File history File links No higher resolution available. ... For other people of the same name, see Harold Wilson. ... Herbert Stanley Allen (December 29, 1873 - April 27, 1954) was a pioneer in early X-ray research, working under J. J. Thomson at the University of London and alongside Nobel laureate Charles Glover Barkla at the University of Edinburgh. ... A schematic representation of the plum pudding model of the atom. ... For other uses, see Electron (disambiguation). ... Isotopes are atoms of a chemical element whose nuclei have the same atomic number, Z, but different atomic weights, A. The word isotope, meaning at the same place, comes from the fact that isotopes are located at the same place on the periodic table. ... Mass spectrometry is a technique for separating ions by their mass-to-charge (m/z) ratios. ... Image File history File links No higher resolution available. ... List of Nobel Prize laureates in Physics from 1901 to the present day. ... The term Anglican describes those people and churches following the religious traditions of the Church of England, especially following the Reformation. ... Joe has no friends what-so-ever Sir George Paget Thomson FRS (May 3, 1892 – September 10, 1975) was a Nobel-Prize-winning, English physicist who discovered the wave properties of the electron by electron diffraction. ... The Order of Merit is a British and Commonwealth Order bestowed by the Monarch. ... The Fellowship of the Royal Society was founded in 1660. ... is the 352nd day of the year (353rd in leap years) in the Gregorian calendar. ... 1856 was a leap year starting on Tuesday (see link for calendar). ... is the 242nd day of the year (243rd in leap years) in the Gregorian calendar. ... Year 1940 (MCMXL) was a leap year starting on Monday (link will display the full 1940 calendar) of the Gregorian calendar. ... Not to be confused with physician, a person who practices medicine. ... The Nobel Prizes (pronounced no-BELL or no-bell) are awarded annually to people who have done outstanding research, invented groundbreaking techniques or equipment, or made outstanding contributions to society. ... For other uses, see Electron (disambiguation). ... Isotopes are atoms of a chemical element whose nuclei have the same atomic number, Z, but different atomic weights, A. The word isotope, meaning at the same place, comes from the fact that isotopes are located at the same place on the periodic table. ... Mass spectrometry is a technique for separating ions by their mass-to-charge (m/z) ratios. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... For other uses, see Electron (disambiguation). ...

Life

J.J Thomson was born in 1856 in Cheetham Hill, Manchester in England, of Scottish parentage. In 1870 he studied engineering at University of Manchester known as Owens College at that time, and moved on to Trinity College, Cambridge in 1876. In 1880, he obtained his BA in mathematics (Second Wrangler and 2nd Smith's prize) and MA (with Adams Prize) in 1883. In 1884 he became Cavendish Professor of Physics. One of his students was Ernest Rutherford, who would later succeed him in the post. He rejected his suitor Rachel Love which left her heartbroken, but in 1890 he married Rose Elisabeth Paget, daughter of Sir George Edward Paget, KCB, a physician and then Regius Professor of Physic at Cambridge. He fathered one son, George Paget Thomson, and one daughter, Joan Paget Thomson, with her. His son became a noted physicist in his own right, winning the Nobel Prize himself for proving the wavelike properties of electrons. Cheetham Hill is a district of Manchester, England located approximately 2 miles to the north of Manchester city centre. ... This article is about the City of Manchester in England. ... This article is about the country. ... Affiliations Russell Group, EUA, N8 Group, NWUA, Worldwide Universities Network (WUN) Website http://www. ... Full name The College of the Holy and Undivided Trinity Motto Virtus vera nobilitas Virtue is true Nobility Named after The Holy Trinity Previous names King’s Hall and Michaelhouse (until merged in 1546) Established 1546 Sister College(s) Christ Church Master The Lord Rees of Ludlow Location Trinity Street... For other uses, see Wrangler. ... The Smiths Prize is a prize awarded to research students in theoretical Physics, mathematics and applied mathematics at the University of Cambridge, Cambridge, England. ... See also the Herbert Baxter Adams Prize of the American Historical Society, and not to be confused with the Douglas Adams Prize for homourous writing The Adams Prize is awarded each year by the Faculty of Mathematics at the University of Cambridge and St Johns College to a young... The Cavendish Professorship is one of the senior Professorships in Physics at Cambridge University and was founded by grace of 9 February 1871 alongside the famous Cavendish Laboratory which was completed three years later. ... Ernest Rutherford, 1st Baron Rutherford of Nelson OM PC FRS (30 August 1871 - 19 October 1937), widely referred to as Lord Rutherford, was a nuclear physicist who became known as the father of nuclear physics. ... The Regius Professorship of Physic is one of the oldest and most prestigious of the professorships at the University of Cambridge, founded by Henry VIII in 1540. ... Joe has no friends what-so-ever Sir George Paget Thomson FRS (May 3, 1892 – September 10, 1975) was a Nobel-Prize-winning, English physicist who discovered the wave properties of the electron by electron diffraction. ...

He was awarded a Nobel Prize in 1906, "in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases." He was knighted in 1908 and appointed to the Order of Merit in 1912. In 1914 he gave the Romanes Lecture in Oxford on "The atomic theory". In 1918 he became Master of Trinity College, Cambridge, where he remained until his death. He died on August 30, 1940 and was buried in Westminster Abbey, close to Sir Isaac Newton. A statue of an armoured knight of the Middle Ages For the chess piece, see knight (chess). ... The Order of Merit is a British and Commonwealth Order bestowed by the Monarch. ... The Romanes Lecture is a prestigious free public lecture given annually at the Sheldonian Theatre, Oxford. ... The University of Oxford (informally Oxford University), located in the city of Oxford, England, is the oldest university in the English-speaking world. ... Full name The College of the Holy and Undivided Trinity Motto Virtus vera nobilitas Virtue is true Nobility Named after The Holy Trinity Previous names King’s Hall and Michaelhouse (until merged in 1546) Established 1546 Sister College(s) Christ Church Master The Lord Rees of Ludlow Location Trinity Street... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the worlds most prestigious universities. ... The Collegiate Church of St Peter, Westminster, which is almost always referred to by its original name of Westminster Abbey, is a mainly Gothic church, on the scale of a cathedral (and indeed often mistaken for one), in Westminster, London, just to the west of the Palace of Westminster. ... Sir Isaac Newton FRS (4 January 1643 – 31 March 1727) [ OS: 25 December 1642 – 20 March 1727][1] was an English physicist, mathematician, astronomer, natural philosopher, and alchemist. ...

Thomson was elected to Fellow of the Royal Society on June 12, 1884 and was subsequently the president of the Royal Society from 1916 to 1920. For other uses, see Royal Society (disambiguation). ... is the 163rd day of the year (164th in leap years) in the Gregorian calendar. ... Year 1884 (MDCCCLXXXIV) was a leap year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Sunday of the 12-day-slower Julian calendar). ... For other uses, see Royal Society (disambiguation). ...

Work on cathode rays

Thomson conducted a series of experiments with cathode rays and cathode ray tubes leading him to the discovery of electrons and subatomic particles. Thomson used the cathode ray tube in three different experiments. A schematic diagram of a Crookes tube apparatus. ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ...

First experiment

In his first experiment, he investigated whether or not the negative charge could be separated from the cathode rays by means of magnetism. He constructed a cathode ray tube ending in a pair of cylinders with slits in them. These slits were in turn connected to an electrometer. Thomson found that if the rays were magnetically bent such that they could not enter the slit, the electrometer registered little charge. Thomson concluded that the negative charge was inseparable from the rays.

Second experiment

Thomson's second experiment.

In his second experiment, he investigated whether or not the rays could be deflected by an electric field (something that is characteristic of charged particles). Previous experimenters had failed to observe this, but Thomson believed their experiments were flawed because they contained trace amounts of gas. Thomson constructed a cathode ray tube with a practically perfect vacuum, and coated one end with phosphorescent paint. Thomson found that the rays did indeed bend under the influence of an electric field. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

Third experiment

Thomson's third experiment.

In his third experiment, Thomson measured the charge-to-mass ratio of the cathode rays by measuring how much they were deflected by a magnetic field and how much energy they carried. He found that the charge to mass ratio was over a thousand times higher than that of a proton, suggesting either that the particles were very light or very highly charged. Image File history File links JJ_Thomson_exp3. ... Image File history File links JJ_Thomson_exp3. ... The charge-to-mass ratio (q/m) of an object is, as its name implies, the charge of an object divided by the mass of the same object. ...

Thomson's conclusions were bold: cathode rays were indeed made of particles which he called "corpuscles", and these corpuscles came from within the atoms of the electrodes themselves, meaning they were in fact divisible. Thomson imagined the atom as being made up of these corpuscles swarming in a sea of positive charge; this was his plum pudding model. This model was later proved incorrect by Ernest Rutherford. Helium atom (schematic) Showing two protons (red), two neutrons (green) and two electrons (yellow). ... A schematic representation of the plum pudding model of the atom. ... Ernest Rutherford, 1st Baron Rutherford of Nelson OM PC FRS (30 August 1871 - 19 October 1937), widely referred to as Lord Rutherford, was a nuclear physicist who became known as the father of nuclear physics. ...

His discovery was made known in 1897, and caused a sensation in scientific circles, eventually resulting in him being awarded a Nobel Prize in Physics in 1906. Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ...

Discovery of isotopes

In the bottom right corner of this photographic plate are markings for the two isotopes of neon: neon-20 and neon-22.

In 1913, as part of his exploration into the composition of canal rays, Thomson channeled a stream of ionized neon through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path. Thomson observed two patches of light on the photographic plate (see image on right), which suggested two different parabolas of deflection. Thomson concluded that the neon gas was composed of atoms of two different atomic masses (neon-20 and neon-22). Image File history File links Discovery_of_neon_isotopes. ... Anode rays (or Canal rays) were observed in experiments by a German scientist, Eugen Goldstein, in 1886. ...

Other work

In 1906 Thomson demonstrated that hydrogen had only a single electron. Previous theories allowed various numbers of electrons.^[1] This article is about the chemistry of hydrogen. ... For other uses, see Electron (disambiguation). ...

Awards

• Royal Medal (1894)
• Hughes Medal (1902)
• Nobel Prize for Physics (1906)
• Copley Medal (1914)

The Royal Medals of the Royal Society of London were established by King George IV. They were further supported with certain changes to their conditions, by King William IV and Queen Victoria. ... The Hughes Medal, named after microphone inventor David Edward Hughes, is one of several medals awarded by the Royal Society, Englands reigning academy of science. ... List of Nobel Prize laureates in Physics from 1901 to the present day. ... The Copley Medal is a scientific award for work in any field of science, the highest award granted by the Royal Society of London. ...

References

• Dahl, Per F., "Flash of the Cathode Rays: A History of J.J. Thomson's Electron". Institute of Physics Publishing. June, 1997. ISBN 0-7503-0453-7
• JJ Thomson (1897), Cathode rays, Philosophical Magazine
• JJ Thomson (1913), Rays of positive electricity, Proceedings of the Royal Society, A 89, 1-20
• "On the Structure of the Atom": an Investigation of the Stability and Periods of Oscillation of a number of Corpuscles arranged at equal intervals around the Circumference of a Circle; with Application of the Results to the Theory of Atomic Structure" — J.J. Thomson's 1904 paper proposing the plum pudding model.
• The Master of Trinity at Trinity College, Cambridge

Full name The College of the Holy and Undivided Trinity Motto Virtus vera nobilitas Virtue is true Nobility Named after The Holy Trinity Previous names King’s Hall and Michaelhouse (until merged in 1546) Established 1546 Sister College(s) Christ Church Master The Lord Rees of Ludlow Location Trinity Street...

External links

Wikimedia Commons has media related to:

Joseph John Thomson

• The Discovery of the Electron
• Annotated bibliography for Joseph J. Thomson from the Alsos Digital Library
• Essay on Thomson life and religious views
• The Cathode Ray Tube site
• Notes on recent researches in electricity and magnetism Cornell University Library Historical Monographs Collection. {Reprinted by} Cornell University Library Digital Collections