J.J Thomson

J.J. THOMSON

  J.J. Thomson was born on December 18, 1856, in Cheetham Hill, England, and went on to attend Trinity College at Cambridge, where he would come to head the Cavendish Laboratory. His research in cathode rays led to the discovery of the electron, and he pursued further innovations in atomic structure exploration. Thomson won the 1906 Nobel Prize in Physics, among many accolades. He died on August 30, 1940. 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.

Personal Life and Later Years

Thomson married Rose Paget, one of his students, in 1890. 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. In addition to being awarded the Nobel Prize in 1906, he was knighted in 1908 by King Edward VII. He left research in 1918 to become Master of Trinity College. Joseph John Thomson, better known as J. J. Thomson, was a British physicist who first theorized and offered experimental evidence that the atom was a divisible entity rather than the basic unit of matter, as was widely believed at the time.

Joseph John Thomson, better known as J. J. Thomson, was a British physicist who first theorized and offered experimental evidence that the atom is a divisible entity rather than the basic unit of matter, as was widely believed at the time. A series of experiments with cathode rays he carried out near the end of the 19th century led to his discovery of the electron, a negatively charged atomic particle with very little mass. Thomson received the Nobel Prize in Physics in 1906 for his work exploring the electrical conductivity of various gases.

The son of a bookseller, Thomson was born on December 18, 1856, in Cheetham Hill, located just north of Manchester, England. He entered Owens College when he was 14 years old, where he became interested in experimental physics, though he had initially intended to pursue a career in engineering. Thomson’s father died only a few years into his college studies, making it financially difficult for Thomson to remain in school. However, through the efforts of his family and scholarships he continued at Owens College until 1876. He then transferred to Trinity College, Cambridge, on a mathematics scholarship. He remained associated with Cambridge University in varying capacities the rest of his life. In 1880, Thomson received a bachelor’s degree in mathematics and became second wrangler, a title bestowed on the second highest-scoring individual on the Cambridge mathematics exams.

Following graduation, Thomson became a Fellow at Trinity College and began work at the Cavendish Laboratory, part of the Cambridge Physics Department. In 1883, he became a lecturer at Cambridge and the following year was appointed Cavendish Professor of Experimental Physics, becoming the successor to Lord Rayleigh. Also in 1884, the Royal Society of London elected Thomson as a Fellow. The receipt of such considerable honors by so young a scientist was highly unusual, but was largely the result of Thomson’s significant early work expanding James Clerk Maxwell’s theories of electromagnetism. Coverage of these efforts, which continued over many years, appeared in Thomson’s 1892 treatise Notes on Recent Researches in Electricity and Magnetism.

In the early 1890s, much of Thomson’s research focused on electrical conduction in gases. During a visit to the United States in 1896, he gave a series of lectures discussing his findings. In 1897, the lectures were published as Discharge of Electricity through Gases. That same year, when Thomson returned to Cambridge, he made his most significant scientific discovery, that of the electron (which he initially referred to as the corpuscle). On April 30, 1897, Thomson made his discovery public while giving a lecture to the Royal Institution. The evidence he produced in support of his theoretical claims was culled from a series of innovative experiments with cathode ray tubes. In one experiment, Thomson attempted to use magnetism to see if negative charge could be segregated from cathode rays, in another he tried to deflect the rays with an electric field, and in a third he assessed the charge-to-mass ratio of the rays. These and additional studies carried out by Thomson and others quickly led to widespread acceptance of Thomson’s discovery.