Arthur B. McDonald is a world-renowned Canadian physicist celebrated for his transformative contributions to particle astrophysics and neutrino physics. Born in 1943 in Sydney, Nova Scotia, he earned his BSc and MSc degrees from Dalhousie University before completing his PhD at the California Institute of Technology in 1969. His distinguished career spanned positions as a Research Officer at the Chalk River Nuclear Laboratories, Professor at Princeton University, and long-standing Professor at Queen's University in Kingston where he achieved emeritus status in 2013. McDonald's visionary leadership established Canada as a global leader in underground physics research through his direction of major international collaborations.
McDonald's most significant scientific breakthrough came through his direction of the Sudbury Neutrino Observatory project, which he led from 1989 after becoming the collaboration's director. In August 2001, his team published definitive observations demonstrating that electron neutrinos from the Sun change flavor during their journey to Earth, providing the first direct evidence of neutrino oscillations. This paradigm-shifting discovery conclusively proved that neutrinos possess mass, fundamentally contradicting the Standard Model of particle physics and requiring new theoretical frameworks to explain subatomic phenomena. For this groundbreaking work that reshaped our understanding of fundamental particles, McDonald shared the 2015 Nobel Prize in Physics with Takaaki Kajita.
Beyond his Nobel-winning research, McDonald continues to actively contribute to fundamental physics as an emeritus professor engaged with the SNO+, DEAP, and DarkSide experiments at SNOLAB. His current research focuses on neutrino-less double beta decay and dark matter interactions using advanced detector technologies including liquid argon and scintillator configurations. McDonald's collaborative leadership style has inspired generations of physicists and established world-class research infrastructure that continues to enable cutting-edge discoveries in particle physics. His legacy extends beyond scientific publications to the creation of enduring international collaborations that maintain Canada's prominent position in the global search for understanding the universe's most fundamental particles.
