Professor Evan James Williams was a preeminent Welsh experimental physicist whose pioneering work significantly advanced atomic and particle physics during the early quantum revolution. Born in the rural village of Cwmsychbant, Cardiganshire in 1903, he demonstrated exceptional mathematical ability from an early age, winning a scholarship to Swansea University at sixteen where he earned first-class honors in physics by 1923. His academic journey continued at Manchester University under Lawrence Bragg, where he completed his doctorate in 1926 for research on X-ray scattering in gases, followed by studies at Cambridge's Cavendish Laboratory with Ernest Rutherford, earning a second doctorate in 1929 for work on electron collisions in gases. Williams progressed through academic appointments at Manchester and Liverpool universities before his ultimate position as Professor of Physics and Head of Department at the University College of Wales, Aberystwyth, where he returned to be near his cherished native Welsh landscapes.
Williams made seminal contributions to the understanding of sub-atomic particles, particularly during his transformative year working with Niels Bohr in Copenhagen in 1933, which many colleagues considered his most productive period. His collaborative work with W.L. Bragg in 1934-1935 produced the influential Bragg-Williams approximation, a fundamental theory explaining how heat affects atomic arrangements in metal alloys that continues to inform statistical physics to this day. At Liverpool, Williams worked alongside James Chadwick, the discoverer of the neutron, and in 1938 became one of the first physicists to obtain concrete evidence of the meson, a newly discovered elementary particle that would revolutionize particle physics. During World War II, his scientific expertise was redirected toward national defense, where he applied operational research methods to develop critical strategies that proved instrumental in countering German submarine threats in the Atlantic, demonstrating the practical application of theoretical physics to vital wartime challenges.
Recognized for his extraordinary intellect and profound physical insights, Williams was elected a Fellow of the Royal Society in 1939, a testament to his standing among Britain's scientific elite. Colleagues including Patrick Blackett paid special tribute to his contributions, noting that physicists continued to miss his deep understanding of physics long after his premature death. Tragically, Williams' promising career was cut short when he died of cancer in 1945 at only 42 years of age, passing away at his parents' home in Brynawel, Carmarthenshire. Despite his brief life span, his legacy endures through the foundational theories that bear his name and his multifaceted contributions to nuclear physics, statistical mechanics, and wartime scientific applications, with subsequent generations of physicists drawing inspiration from his work that helped bridge classical and quantum understandings of the atomic world.
