John Edward Lennard-Jones
Lennard-Jones, John Edward (1894-1954) was an English theoretical physicist. He was born John Edward Jones in Leigh, Lancashire, England, and was the son of a merchant. He received a degree in mathematics at Manchester University in 1915. After serving as a pilot in the Royal Flying Corps during World War I (1914–1918), he obtained his Ph.D. in 1924 at Cambridge University. He changed his name to Lennard-Jones in 1925, when he married Kathleen Mary Lennard.
Lennard-Jones held teaching positions at Manchester and Cambridge before becoming a reader in theoretical physics at Bristol University in 1925 and professor of theoretical physics there in 1927. Theoretical physicists create laws and theories that are expressed mathematically. Their ideas are tested by experimental physicists.
In the early 1920's, Lennard-Jones attempted to produce a formula from which forces between atoms could be calculated. A mathematical expression for intermolecular forces, which he produced at Cambridge, bears his name and is still widely used in statistical mechanics.
Lennard-Jones also helped develop the molecular-orbital theory introduced by American chemist Robert Sanderson Mulliken (1896–1986), and he became a leading supporter of it. Mulliken won the 1966 Nobel Prize in chemistry for the theory, which describes the arrangement of electrons in molecules.
In 1932, Lennard-Jones returned to Cambridge, where he became the first chair of theoretical chemistry. During World War II (1939–1945), he contributed to the war effort, especially as Chief Superintendent of Armament and Research in the Ministry of Supply. He was knighted in 1946.
Lennard-Jones became principal of the University College of North Staffordshire in 1953. He was elected Fellow of the Royal Society in 1933 and received its Davy medal in 1953. From 1948 to 1950, he also served as president of the Faraday Society.