He was awarded the BHP Medal in 1967 as the top student in South Australia in Mathematics, Physics and Chemistry in the (new) Matriculation Examinations.
[1] From 1973 to 1975 Thomas was Killam Postdoctoral Fellow at the University of British Columbia, then from 1975 to 1976 was Scientific Associate of the European Organization for Nuclear Research (CERN) in Geneva.
With Harold Fearing he was a founding member of the theory group at TRIUMF (Canada's National Laboratory for Particle and Nuclear Physics) in Vancouver, where he carried out research from 1976 to 1982.
In 1990 he was appointed Elder Professor of Physics at the University of Adelaide, and was elected a Fellow of the Australian Academy of Science.
[2] From 2004 to 2009 he served as Chief Scientist and associate director for Theoretical and Computational Physics at Thomas Jefferson National Accelerator Facility.