Sir Ralph H. Fowler OBE FRS
Born	Ralph Howard Fowler (1889-01-17)17 January 1889 Roydon, Essex, England
Died	28 July 1944(1944-07-28) (aged 55) Trumpington, Cambridgeshire, England
Alma mater	Trinity College, Cambridge
Known for	Formulating Zeroth law of thermodynamics Darwin–Fowler method Bernal–Fowler rules Fowler–Nordheim tunneling Degenerate matter
Spouse	Eileen Mary Rutherford ​ ​ (m. 1921)​
Children	4, including Ruth
Relatives	Ernest Rutherford (father-in-law) Robert Edwards (son-in-law) Mary Fowler (granddaughter)
Awards	Rayleigh Prize (1913) Adams Prize (1924) FRS (1925)[1] Royal Medal (1936)
Scientific career
Fields	Physics
Institutions	University of Cambridge
Academic advisors	Archibald Vivian Hill
Doctoral students	Homi J. Bhabha Garrett Birkhoff S. Chandrasekhar Paul Dirac Douglas Rayner Hartree John Lennard-Jones Daulat Singh Kothari[2] Harrie Massey William McCrea Nevill Francis Mott Maurice Pryce Bertha Swirles Wang Zhuxi

Sir Ralph Howard Fowler (17 January 1889 – 28 July 1944) was an English physicist.

Ralph H. Fowler was born at Roydon, Essex, on 17 January 1889 to Howard Fowler, from Burnham, Somerset, and Frances Eva, daughter of George Dewhurst, a cotton merchant from Manchester.^[3] He was initially educated at home, going on to attend Evans' preparatory school at Horris Hill and Winchester College. He won a scholarship to Trinity College, Cambridge and studied mathematics, becoming a wrangler in Part II of the Mathematical Tripos.

In World War I he obtained a commission in the Royal Marine Artillery and was seriously wounded in his shoulder in the Gallipoli campaign. The wound enabled his friend Archibald Hill to use his talents properly. As Hill's second in command he worked on anti-aircraft ballistics in the Anti-Aircraft Experimental Section of HMS Excellent on Whale Island. He made a major contribution on the aerodynamics of spinning shells. He was awarded the OBE in 1918.^[4]

In 1919, Fowler returned to Trinity and was appointed college lecturer in mathematics in 1920. Here he worked on thermodynamics and statistical mechanics, bringing a new approach to physical chemistry. With Arthur Milne, a comrade during the war, he wrote a seminal work on stellar spectra, temperatures, and pressures. In 1925 he was made a Fellow of the Royal Society.^[1] He became research supervisor to Paul Dirac and, in 1926, worked with him on the statistical mechanics of white dwarf stars. In 1927 he was one of the participants of the fifth Solvay Conference on Physics that took place at the International Solvay Institute for Physics in Belgium. In 1928 he published (with Lothar Nordheim) a seminal paper that explained the physical phenomenon now known as field electron emission, and helped to establish the validity of modern electron band theory. In 1931, he was the first to formulate and label the zeroth law of thermodynamics.^[5] In 1932 he was elected to the Chair of Theoretical Physics at the Cavendish Laboratory. In 1933 he worked with John Bernal to develop a model for the structure of water and ice known as the ice rules.^[6]

In 1939, when World War II began, he resumed his work with the Ordnance Board, despite poor health, and was chosen for scientific liaison with Canada and the United States. He knew America well, having visiting professorships at Princeton and the University of Wisconsin–Madison. For this liaison work he was knighted in 1942 (see MAUD Committee). He returned to Britain later in the war and worked for the Ordnance Board and the Admiralty up until a few weeks before his death in 1944.

Fifteen Fellows of the Royal Society and three Nobel Laureates (Chandrasekhar, Dirac, and Mott) were supervised by Fowler between 1922 and 1939. In addition to Milne, he worked with Sir Arthur Eddington, Subrahmanyan Chandrasekhar, Paul Dirac, Homi J. Bhabha, and Sir William McCrea. It was Fowler who introduced Dirac to quantum theory in 1923. Fowler also put Dirac and Werner Heisenberg in touch with each other through Niels Bohr. At Cambridge he supervised the doctoral studies of 64 students, including John Lennard-Jones, Paul Dirac and Garrett Birkhoff.

The Fowler Islands, in Crystal Sound, on the Antarctic Peninsula were named by the UK Antarctic Place-Names Committee in his honour.

Fowler was a keen amateur cricketer who played as a wicket-keeper. He played for Norfolk in the Minor Counties Championship in 1908 and 1909.^[7]

In 1921 he married Eileen Mary (1901–1930), the only daughter of Ernest Rutherford. They had four children, two daughters and two sons. Eileen died after the birth of their last child, Ruth Fowler Edwards, a geneticist and wife of Robert G. (Bob) Edwards, the "father" of in vitro fertilization and 2010 Nobel Prize in Physiology or Medicine laureate. One of his grandchildren is Mary Fowler, a geophysicist and the sixth Master (2012–2020) of Darwin College, Cambridge.^[8]

• Elementary differential geometry of plane curves. Cambridge tracts in mathematics and mathematical physics .. ;No. 20. Cambridge University Press. 1920.^[9] Dover reprint. 2005.
• Statistical mechanics, the theory of the properties of matter in equilibrium; based on an essay awarded the Adams prize in the University of Cambridge, 1923–24. Cambridge University Press. 1929.^[10][11] 2nd edition. 1936.^[12]
• Passage of electrons through surfaces and surface films; being the thirty-first Robert Boyle lecture. Oxford University Press. 1929.
• with E. A. Guggenheim: Statistical thermodynamics: a version of statistical mechanics for students of physics and chemistry. Cambridge University Press. 1939.^[13]

• Biography of Ernest Rutherford, with names of Ralph & Eileen's children
• Ralph Howard Fowler Trinity College Chapel
• Durham, Ian T. (2001). "Ralph Fowler (Biography)". Saint Anselm College, MacTutor History of Mathematics archive. Retrieved 29 December 2024.