J J Thomson
- Category : Science-Physics
- Type : MGE
- Profile : 5/1 - Heretical / Investigator
- Definition : Split - Small (1,16,20,45)
- Incarnation Cross : LAX Education 2
English physicist who helped revolutionize the knowledge of atomic structure by his discovery of the electron (1897). He received the Nobel Prize for Physics in 1906 and was knighted in 1908.
Thomson worked in the Cavendish Laboratory after graduation, under the tutelage of Lord Rayleigh. He quickly earned a membership in the prestigious Royal Society and was appointed Rayleigh’s successor as the Cavendish Professor of Physics at the age of 28. He was both respected and well-liked, and students came from around the world to study with him.
In 1894, Thomson began studying cathode rays, which are glowing beams of light that follow an electrical discharge in a high-vacuum tube. It was a popular research topic among physicists at the time because the nature of cathode rays was unclear.
Thomson devised better equipment and methods than had been used before. When he passed the rays through the vacuum, he was able to measure the angle at which they were deflected and calculate the ratio of the electrical charge to the mass of the particles. He discovered that the ratio was the same regardless of what type of gas was used, which led him to conclude that the particles that made up the gases were universal.
Thomson determined that all matter is made up of tiny particles that are much smaller than atoms. He originally called these particles 'corpuscles,' although they are now called electrons. This discovery upended the prevailing theory that the atom was the smallest fundamental unit.
In 1906, Thomson began studying positively charged ions, or positive rays. This led to one of his other famous discoveries in 1912, when he channeled a stream of ionized neon through a magnetic and an electric field and used deflection techniques to measure the charge to mass ratio. In doing so, he discovered that neon was composed of two different kinds of atoms, and proved the existence of isotopes in a stable element. This was the first use of mass spectrometry.
To a large extent, it was Thomson who made atomic physics a modern science. The studies of nuclear organization that continue even to this day and the further identification of elementary particles all followed his most outstanding accomplishment, his discovery of the electron in 1897. Although this new physics has continued to raise more theoretical questions than can be answered at present, from the start it rapidly gave rise to practical applications in technology and industry.
Thomson married Rose Paget, one of his students, in 1892. They had one daughter, Joan, and one son, George Paget Thomson, who went on to become a physicist and win a Nobel Prize of his own. J.J. Thomson published 13 books and more than 200 papers in his lifetime.
He died in Cambridge on 30 August 1940, and is buried in Westminster Abbey near two other influential scientists: Isaac Newton and Charles Darwin.