Having a keen interest in politics, Crewther was vice-president of the University of Adelaide branch of the National Tertiary Education Union.[2] He also served on the University Council.[3]
Teaching
He designed the honours physics course "Gauge Field Theories." He also lectured on Quantum Mechanics III, Advanced Dynamics and Relativity, and Honours Quantum Field Theory. For courses Quantum Mechanics II, Honours Relativistic Quantum Mechanics and Particle Physics, and Classical Fields and Mathematical Methods, his notes were followed by his successors.
Dr Crewther also taught a 4-week module of Physics 1B at the University of Adelaide where he hosted mechanics lectures that focused on the centre of mass, rotation, angular momentum and gyroscopic precession.[4]
Death
He died in 2020 around Christmas time from cancer.[5]