Changing our understanding of the innermost workings of matter
A professor emeritus at Queen’s University in Kingston, Dr. Arthur B. McDonald is the co-winner of the 2015 Nobel Prize in Physics. He shares the prize with Takaaki Kajita of the University of Tokyo.
The two men won the prize for their contributions to experiments demonstrating that particles called neutrinos can change identities or “oscillate” as they travel from the sun. The neutrinos — subatomic particles that whizz through the universe at nearly the speed of light — transform themselves between three types: electron, muon and tau.
The transformation requires that neutrinos have mass, dispelling the long-held notion that they were massless. The Royal Swedish Academy of Sciences said the discovery “has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe.”
Dr. McDonald’s work, carried out by a team of scientists from Canada, the United States, Britain and Portugal, took place at the Sudbury Neutrino Observatory (SNO). A collaborative effort by six Canadian universities (Carleton University, Laurentian University, Queen’s University, the University of British Columbia and the University of Guelph), SNO is situated two kilometres underground at a working nickel mine. Now called SNOLAB, it is Canada’s leading edge astroparticle physics research facility. According to Dr. McDonald, the work could only have been performed in Canada.
A Companion of the Order of Canada, Dr. McDonald is director of the Sudbury Neutrino Observatory Institute and holds the Gordon and Patricia Gray Chair in Particle Astrophysics at Queen’s University in Kingston. Among other distinctions, he received the 2015 Fundamental Physics Prize.
* Arthur B. McDonald is one of 24 Canadian winners of major international research awards in 2015 featured in the publication Canadian excellence, Global recognition: Celebrating recent Canadian winners of major international research awards.