Remembering: Edwin Mattison McMillan, 35 Years On (d. September 7, 1991)

Today marks the 35th anniversary of the passing of Edwin Mattison McMillan, a distinguished American physicist whose work fundamentally changed our understanding of the atomic world. Born on September 18, 1907, in Redondo Beach, California, McMillan dedicated his life to the pursuit of scientific discovery. He passed away on September 7, 1991, leaving behind a profound legacy in the fields of chemistry and physics. His contributions remain a cornerstone of modern nuclear research and particle acceleration technology. Throughout his career, he was recognized for his intellectual rigor and his ability to solve complex problems in experimental physics. His work at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory placed him at the center of the most significant scientific advancements of the 20th century. McMillan is perhaps best known for his discovery of neptunium, the first transuranium element, which he identified in 1940 alongside Philip Abelson. This groundbreaking achievement opened the door to the synthesis of many other elements that follow uranium on the periodic table. His research provided essential insights into the behavior of heavy elements and the nature of nuclear fission. In 1951, he was awarded the Nobel Prize in Chemistry, an honor he shared with Glenn T. Seaborg for their pioneering work in the chemistry of transuranium elements. Beyond his work with elements, McMillan made a historic contribution to the development of particle accelerators. He independently conceived the principle of phase stability, which allowed for the creation of the synchrotron. This innovation enabled scientists to accelerate particles to much higher energies than previously possible, facilitating new discoveries in high-energy physics. His invention transformed the design of accelerators worldwide, leading to the construction of massive machines that continue to probe the fundamental building blocks of matter. During the Second World War, McMillan also contributed his expertise to the Manhattan Project, working on radar and nuclear weapons development. His involvement in these high-stakes projects highlighted his versatility as a scientist and his commitment to national service. After the war, he returned to academic and research pursuits, eventually serving as the director of the Lawrence Berkeley National Laboratory from 1958 to 1973. Under his leadership, the laboratory continued to be a global hub for scientific innovation and interdisciplinary research. Colleagues and students often remembered him as a humble and thoughtful mentor who encouraged curiosity and precision. His influence extended far beyond his own laboratory, as he helped shape the direction of nuclear science for decades. Today, the scientific community reflects on his life and the enduring impact of his discoveries on modern technology and medicine. His work continues to inspire new generations of physicists to explore the mysteries of the universe.