Authorised form of nameEssen; Louis (1908 - 1997)
Dates1908 - 1997
Place of birthNottingham, England, United Kingdom
Date of birth06/09/1908
Place of deathGreat Bookham, Surrey, England, United Kingdom
Date of death24/08/1997
Research fieldTime
Atomic clocks
Speed of light
University College, Nottingham, external degree granted from University of London, BSc in physics (1928); University of London PhD (1941), DSc (1948)
National Physical Laboratory (1929-1972); during the second world war worked on radar, developing ways of measuring frequencies; developed a new method to determine the speed of light; developed the first practical atomic clock in collaboration with Jack Parry; advocated replacing the ephemeris second with the atomic standard, ratified by international agreement in 1968; retired 1972
OBE 1959
Wolfe award of the Department of Scientific and Industrial Research; Popov gold medal of the USSR Academy of Sciences
Membership categoryFellow
Date of election24/03/1960
Age at election51
RelationshipsWorked with D W Dye (FRS 1928) at NPL; married Joan Margery Greenhalgh (1937)
Published works
Wikipedia; ODNB; PIF
Essen, R 'The Birth of Atomic Time' (Peterborough) 2015
Essen, R 'Revolutions in Time. The World of Louis Essen, clockmaker and father of atomic time' (2020)
Biographical Memoirs of Fellows of the Royal Society 1998 vol 44 pp 141-158, plate, by Sir Alan Cook
Virtual International Authority File
Royal Society codeNA2141
Archives associated with this Fellow
Reference numberTitleDate
IM/001311Essen, LouisCirca 1984
RR/49/105Referee's report by William Henry Eccles, on a paper 'The valve maintained tuning fork as a primary standard of frequency' by William David Dye and Louis Essen[October 1933]
RR/53/57Referee's report by William Henry Eccles, on a paper 'International frequency comparisons by means of standard radio frequency emissions' by Louis Essen[February 1935]
RR/59/64Referee's report by Arthur Mannering Tyndall, on a paper 'The dye quartz ring oscillator as a standard of frequency and time' by Louis Essen[February 1936]
RR/70/99Referee's report by John Turton Randall, on a paper 'The velocity of propagation of electromagnetic waves derived from the resonant frequencies of a cylindrical cavity resonator'by Louis Essen and A C Gordon-Smith1947
EC/1960/08Essen, Louis: certificate of election to the Royal Society
RR/62/102Referee's report by James Hopwood Jeans, on a paper 'The effect of the fitzgerald-lorentz contraction on the frequency of longitudinal vibration of a rod' by A B Wood, G A Tomlinson and Louis Essen[September 1936]
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