Arthur Melville (Mel) Thompson [1917-2009]

Biography

Arthur Melville (Mel) Thompson was born in Adelaide on 4 January 1917 and died in Sydney on 8 August 2009. After graduating with honours in physics from the University of Adelaide, he joined the CSIRO National Standards Laboratory. He spent the whole of his working life there, retiring in 1982 from his position as a Chief Research Scientist in the Division of Applied Physics, as the laboratory was then known. His retirement marked the end of an era for the laboratory, as he was the last of the original nine scientists of whom it was originally constituted. After his retirement he continued his work for a time as an Honorary Senior Research Fellow.

Thompson’s major contribution was to the precise measurement of physical quantities, particularly electrical, which formed the basis of a revolution in accurate measurement all over the world. In 1956, he and Douglas Lampard (later FAA) produced a new theorem in electrostatics which allowed the electrical capacitance of a four-cylinder system to be calculated in absolute terms from a single measurement of length, made by interferometry with great precision.

This formed the basis for the design and construction of the Lampard-Thompson capacitor, which was universally accepted as the most accurate method for realising the farad and the ohm absolutely. This and his development of three-terminal capacitors and a.c. bridges incorporating ratio transformers enabled him to relate the ‘ohm’ to absolute measurements of length and time accurately and simply. His suggestion to use capacitance probes for sensing displacement and the commercial development of his a.c. bridge greatly increased the accuracies obtainable over a wide range of physics research, e.g. with geophysical tiltmeters, magnetostriction, thermal expansion and pressure gauges.

Honours and awards

For his contributions to science Mel received many awards including:

Source

• White GK, 2009, Personal communication.