122. Evan James Williams (FRS)
Prof Andrew Evans, Dr Huw Morgan
Born in Cwmsychbant, Ceredigion on the 8th June 1903, EJ Williams went on to work with the most eminent physicists of the day, including Ernest Rutherford, James Chadwick, Lawrence Bragg and Niels Bohr.
The Bragg-Williams approximation was used to explain the cooling of hot alloys and is useful for solving many problems in statistical physics.
The Weizäcker-Williams theoretical method for analysing atomic collisions can be applied to a wide range of situations.
In 1938, EJ Williams was appointed a Chair in Physics at the then University College of Wales, Aberystwyth where he continued his studies on sub-atomic particles using a cloud chamber and where he became the first person to detect and photograph the decay of a muon (µ) particle.
During the Second World War, he joined a group of scientists who were tasked with developing statistically based strategies to combat U-boats in the Atlantic, eventually becoming the group leader. EJ Williams sadly died of cancer on 29th September 1945.
Prof Andrew Evans
Dr Huw Morgan