Published in the Research School of Physics Event Horizon
Vol43 Issue72 4–8 June 2018

Lindsay James Tassie

31st August, 1930 – 29th May, 2018

Written and delivered by Professor Brian Robson 8th June 2018 at St Paul’s Anglican Church, Manuka

Margaret asked me to speak a little about Lindsay's academic work.

I have known Lindsay for over 60 years. We met in 1955 while we were both undertaking postgraduate studies in theoretical physics at the University of Melbourne. Lindsay was completing his PhD thesis, while I commenced an MSc degree. Lindsay came to the ANU in 1956 and I followed him to the ANU in 1960 to join the Department of Theoretical Physics in the then Research School of Physical Sciences.

Lindsay was a member of the Academic Staff of the Department of Theoretical Physics from 1956 to 1995, except for the period 1962 to 1968 when he was appointed as a Senior Lecturer and later Reader in the then School of General Studies. In 1968 he was appointed Senior Fellow in the Department of Theoretical Physics and continued as a Visiting Fellow since his 'retirement' in January 1996.

During his time in the Faculties, Lindsay taught many undergraduate courses in Theoretical Physics. Later he published a book entitled "The Physics of Elementary Particles" in 1973, which was very successful and was later translated into German and published in Germany and Austria. Many students, especially in Australia and Germany were introduced to particle physics via his book.

Lindsay made many overseas visits, including one year at each of the Weizmann Institute of Science and the Argonne National Laboratory during 1959 to 1961. He was on study leave at Indiana University during 1965, the Technische Hochschule Darmstadt in 1974 and the University of Bonn in 1988. He travelled the world.

Lindsay was a very original and creative theoretical physicist, who was primarily interested in solving fundamental problems. In my opinion, Lindsay approached his research like the strong cyclist who tended to break-away from the main group of riders in the peloton pack of the Tour de France. He liked to initiate research with new ideas.

In his earlier years, he made important contributions to the theory of electron scattering by nuclei. In particular, he introduced the Tassie model, which treats motion in a nucleus as the incompressible motion of an inhomogeneous fluid. This model has since been widely employed to describe the inelastic scattering of various projectiles by nuclei.

In 1973 Lindsay was the first to introduce the idea of a string as a vortex of quantized flux. This idea was discovered independently also in 1973 by Nielsen and Olesen, who refer to Lindsay's paper in their paper that has to date accumulated nearly 2000 citations. The idea of a string as quantised flux has been very fruitful in particle physics.

More recently, Lindsay has worked with string theory, making important contributions to the Aharonov-Bohm effect, the theory anyons and the theory of superconducting cosmic strings.

Lindsay wrote most of his papers at a time when quality was more important the quantity: Lindsay’s papers were of the highest quality. He will be long remembered.