Bryan Kibble

Bryan Peter Kibble (20 October 1938 – 28 April 2016) was a British physicist and a pioneering metrologist. He was the inventor of the Kibble balance, an improved version of the current balance, developed for the realisation of the S.I. unit of mass, the kilogram.

Early years and family Kibble was born in Letcombe Regis (formerly in Berkshire, now part of Oxfordshire) to Ellen and Herbert Kibble. His father was a police sergeant. He was the youngest of four children. From an early age he enjoyed repairing electrical and mechanical devices. He attended Abingdon School from 1950 to 1957, where he was a house prefect and gained significant academic success. He won numerous prizes for physics, mathematics and science and was awarded a Bennett Scholarship. He was a member of the Debating and Roysse Society in addition to playing for the hockey and rugby teams.

He was awarded an open scholarship to study Natural Science at Jesus College, Oxford. He met his future wife, Anne Greenfield, there and they married in 1964, the same year that he was awarded his DPhil on the subject of atomic spectroscopy. They had three children, Paul, Nicola and Stephen.

Career Kibble moved to Canada after completing his DPhil as a post-doctoral fellow at the University of Windsor, Ontario. Two years later, he returned to England and spent the following thirty years at the National Physical Laboratory (NPL) in Teddington as a senior research fellow.

The Kibble balance Kibble worked with Greville Rayner on coaxial a.c. bridges and the calculable capacitor from which the ohm could be realised, publishing in 1984. Prior to this he had been exercised by the problems with the current balance and had ideas for its improvement. Supported in his thinking during a visit by Robert D. Cutkosky of the National Institute of Standards and Technology of the US, Kibble invented the moving-coil watt balance in 1975. In 1978 the Mark I watt balance was built at NPL with Ian Robinson and Ray Smith. A more accurate realisation of the ampère was made, therefore the current balance had been superseded. This development led to the internationally accepted setting of the conventional Josephson and von Klitzing constants in 1990, obviating any further justification for national representations of these values which had previously inhibited trade. International teams developed their own versions of the balance.

Later years Kibble retired from N.P.L. in 1998, but continued to work in the field at N.P.L., the Physikalisch-Technische Bundesanstalt in Braunschweig, the B.I.P.M., and he also visited many other metrological institutions worldwide with his wife, Anne. From 2009, he wrote for the IEEE Instrumentation and Measurement Magazine. In 2010, he published Coaxial Electrical Circuits for Interference-Free Measurements with Jurgen Schurr and Shakil Awan.

Other interests Kibble enjoyed playing the clarinet, umpiring hockey matches, and genealogy.

Awards Gabor Medal and Prize (formerly the Duddell Medal and Prize), 1986 I.U.P.A.C. SUNAMCO Senior Scientist Medal, 1992 IEEE Joseph F. Keithley Award in Instrumentation and Measurement, 2009