In 1870, at the age of 14, Thomson went to Owens College (nowUniversity of Victoria）Study engineering.Entered in 1876Trinity College, Cambridge UniversityHe studied mathematics and obtained a bachelor's degree in 1880.In 1881, he became an academician of Trinity College.In 1883, he obtained a master's degree and served as a lecturer in mathematics in Trinity College.In 1884, he began to serve as the Cavendish professor of physics at Cambridge University, namely the director of Cavendish Laboratory, and was elected an academician of the Royal Society of England.Professor of the Royal Society of England in 1905.He won the Nobel Prize in Physics in 1906.He was knighted in 1908.President of the Royal Society from 1916 to 1920.In 1918, he served as Dean of Trinity College, Cambridge University.He died in Cambridge on August 30, 1940, aged 84.[1-4]
Thomson is mainly engaged ingas discharge 、electromagnetics、atomic structureIn 1897, he studied the vacuum tubeCathode rayThe existence of electrons was proved in the experiment.In addition to his contributions to physics research, Thomson is an outstanding teacher and has trained seven Nobel Prize winners.[2][5][7]
Joseph John Thomson was born in Manchester, England, on December 18, 1856.He was educated in a small private school in his early years, and was interested in science since childhood. His initial goal was to become an engineer[1][3]。
In 1870, his father intended to send him to an engineering company as an apprentice, but since there was no vacancy, Thomson, who was only 14 years old, was sent to Owens College in Manchester (nowUniversity of Victoria）Study engineering.During his study, his mathematical and scientific abilities were recognized. He devoted himself to physical research and published a short paper on "contact between insulators" in the Journal of the Royal Society.He almost lost his sight in an experimental explosion[1]。
In 1880, participated in theUniversity of CambridgeI got my bachelor's degree in mathematics with second place in the degree examination.Before graduation, he published two small papers on pure mathematics.In the same year, he began to study at Cambridge UniversityCavendish LabWork under the second director of Cavendish LaboratoryLord Raleigh[3]。
In 1881, he was elected as a bachelor of Trinity College and began to engage in the research of mathematics and experimental physics[1]。
In 1883, he received a master's degree from Cambridge University and served as a lecturer in mathematics at Trinity College for one year[4]。
In 1884, Lord Raleigh resigned, and Thomson began to serve as the physics professor of Cavendish Laboratory, replacing the director of Cavendish Laboratory[1][3]；On June 12, he was elected as an academician of the Royal Society[6]。
In 1897, Thomson proved the existence of electrons in the vacuum tube cathode ray experiment, and concluded that electrons are part of atoms;On April 30, he announced this discovery in a speech to the Royal Society[2-3]。A month later, he calculated the mass charge ratio of the electron[8]。
In 1912, he won the Medal of Merit and was knighted[2][5]。
President of the Royal Society from 1916 to 1920[4]。
In 1918, he served as the Dean of Trinity College of Cambridge University and resigned as the Director of Cavendish Laboratory, retaining the title of Professor of Physics[1]。
Thomson died in Cambridge on August 30, 1940, aged 84[2]。
Key achievements
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Scientific research achievements
Research overview
Thomson's early research line mainly focused on three aspects:Adams AwardRequired research topics;Mathematical development of Maxwell's electrodynamics;Dynamic Application of Lagrange Formula[20]。
During the 35 years when Thomson led the Cavendish Laboratory, the laboratory's research work has made the following achievements: the study of gas conduction led to the discovery of electrons;Radioactive research has led toAlpha ray、Beta rayDiscovery of;Carried outPositive rayAnd inventedMass spectrometer, resulting inisotopeResearch;The invention of the expansion cloud chamber has prepared the conditions for the research of nuclear physics and basic particles;The research of electromagnetic wave and thermionic led to the invention and improvement of vacuum tube, and promoted the development and application of radio electronics.[10]
He also pointed out in a paper on energy conversion that energy must have both mass and momentum, thus partially predicting the wave particle duality of moving charged particles and Einstein's mass energy relationship
。[9]
In 1905, Thomson discoveredpotassiumNatural radioactivity.[12]
In 1883, Thomson wrote an articleNucleusHis award-winning paper on the theory of vortex rings, and from this he began his experimental research on gas discharge.third personX-rayThe phenomenon that makes the gas conduct electricity is "ionization", and through the study of ionization phenomenon, it is confirmed that cathode rays are very small charged particles.
Thomson's experimental instrument for discovering electron
。He found that the charge mass ratio of this particle is aboutFaradayThe charge mass ratio of the lightest atom discovered is 2000 times, which first provides direct evidence of the existence of electrons.Later, he conducted electromagnetic deflection experiments andWilson Cloud ChamberThe electron was finally confirmed in the track observation of the, so as to determine that all substances contain at least the common component of the electron.In 1899, Thomson used Wilson cloud chamber to measure the charge and mass of electrons.The electron charge measured by Thomson and Wilson is 1 × 10-19Library with a quality of 10-31Kilograms.[7][9]
Thomson called electrons "corpuscles" at that time, but later scholars used "electron" to call electrons. This word was proposed by Johnstone Stoney in 1891, which was earlier than Thomson's actual discovery of electrons.[3]
Thomson also proposed the atomic“Atomic structure model of raisin pudding”(also known asThomson model）However, later experiments proved that this model was incorrect.In addition, after studying the scattering of X-rays by electrons in atoms, Thomson combinedBaccaratIt is proved that the number of electrons in the atom is about half of the atomic mass number, and the importance of atomic number is pointed out.[9]
Academic works
time
name
1883
Treatise on the Motion of Vortex Rings
1886
Application of Dynamics to Physics and Chemistry
1892
Notes on Recent Research in Electricity and Magnetism
1898
The Discharge of Electricity through Gases
1903
Conduction of Electricity through Gases
1907
The Structure of Light
1907
The Corpus Theory of Matter
1913
Rays of Positive Electricity
1923
The Electron in Chemistry[2]
academic exchange
In 1896, Thomson visited the United StatesPrinceton University He gave four lectures and summarized his research achievements[2]。
In 1904, Thomson was in the United StatesYale UniversityGave six lectures on electricity and matter[2]。
personnel training
Teaching work
As the director of Cavendish Laboratory, Thomson not only taught professional courses to graduate students, but also offered basic physics courses to undergraduate students.From 1884 to 1895, he insisted on teaching four to seven courses to students every school year.Its teaching workload was far more than the Cambridge regulation of "opening at least one course every two semesters" at that time, and also greatly exceeded the task of two predecessors who only took two or three courses each academic year.
He made some reforms to the curriculum of Cavendish Laboratory.The former degree examination course is divided into two parts, and mathematics courses for physics majors and experimental demonstration contents in mathematics degree examination are added respectively.[20]
Teaching philosophy
Thomson takes teaching very seriously.He believes that teaching itself is helpful to scientific research. Through teaching, he can often re-examine the views that he took for granted.He never requires people entering new research fields to start from reading existing literature. On the contrary, Thomson believes that scientific research is to clarify their own views first, and then consult the scientific research achievements of others, so that they are not affected by any assumptions.[5]
Laboratory construction
Thomson has made outstanding contributions to the construction of Cavendish Laboratory.He expanded the scale of the laboratory not only through self financing and raising funds, but also in response to the problems of insufficient funds, weak faculty and extremely crowded research space.By adopting different teaching systems for the junior class and the senior class, the requirements of university teaching are met and the teaching quality is ensured.[20]
At Thomson's suggestion, since 1895, Cavendish Lab has implemented the system of recruiting graduates from other universities and foreign universities to become graduate students, and has taken the lead in implementing the system of opening to female students, establishing a complete set of management systems for cultivating graduate students, and establishing a good style of study.Groups of outstanding young scholars have come here to study and research under the guidance of Thomson.Among the graduate students of various countries who were taught by Thomson between 1885 and 1914, many later became famous scientists, of whom 7 won the Nobel Prize and 27 won the membership of the Royal Society of England.[10][20]
Cultivate students
According to the data from the website of the Math Pedigree Project in December 2023, Thomson has guided 15 students, including 7 Nobel Prize winners. The details are as follows:
Member of British Invention and Research Commission[1]
1916-1920
President of the Royal Society[2]
Personal life
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Family background
Thomson color photo
Joseph James Thomson, the father of Joseph John Thomson, is a bookseller with pure Scottish blood[1]。Emma Swindells (1831-1901) came from a family that ran a textile company[17]。Thomson also has a younger brother called Frederick Vernon Thomson (1859-1917)[16]。
Family marriage
In 1890, Thomson married the former student Rose Elizabeth Paget (1860-1951), the daughter of Sir George Edward Paget, a Cambridge medical professor in England[18]。They have a sonGeorge Paget Thomson(1892-1975, 1937) and a daughter Joan (1903-1987,Joan Paget Thomson）[19]。
hobby
Thomson has a remarkable talent in finance. He manages his investments low-key and starts to earn considerable wealth with very little capital.In addition, he is an amateur gardener who is particularly interested in plants and bulbs[1]。
Character evaluation
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Thomson, who discovered electrons, was praised by later generations as "the first scientist to open the door to elementary particle physics"[9]。(Jimei University Review)
"Thomson is a strange link between new and old physics. He has opened the door to new physics, but he has never entered it."[20]（William Henry Bragg Comment)
From the 1890s to the 1940s, the Cavendish Laboratory has always had a research group with its professors as the core, namely the Cavendish School, whose great founder is Thomson[20]。（《Modern Physics Knowledge》Comment)
Commemoration for future generations
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In recognition of his outstanding contribution, Thomson thanked the world and his ashes were buried inWestminster AbbeyIn the center of, andNewton、Darwin、KelvinWhen the ashes of scientists are put together[20]。
In 1991, in memory of Joseph John Thomson, the name "Thomson" was proposed as the unit of mass charge ratio in mass spectrometry, with the symbol "Th".[13]
In 1985, the International Mass Spectrometry Foundation named the Thomson Medal Award after Thomson.[14]
In 2008, the British Institute of Physics Thomson named the "Joseph Thomson Medal and Prize" to commend those who have made outstanding contributions to atomic or molecular physics.[15]
