Search just our sites by using our customised search engine
Unique Cottages | Electric Scotland's Classified Directory

Click here to get a Printer Friendly PageSmiley

Significant Scots
Arthur MacDonald

Arthur B. McDonald, 2015 Nobel Prize in Physics

Arthur McDonald, a professor emeritus at Queen's University in Kingston, Ont., is the co-winner of the 2015 Nobel Prize in Physics.

McDonald shares the prize with Takaaki Kajita of the University of Tokyo.

The winners were announced by a committee at the Royal Swedish Academy of Sciences in Stockholm on Tuesday. McDonald and Kajita will split the eight million Swedish kronor (almost $1.3 million Cdn) prize.

The academy said the two men won the prize for their contributions to experiments demonstrating that subatomic particles called neutrinos change identities, also known as "flavours." The neutrinos transform themselves between three types: electron-type, muon-type and tau-type.

The metamorphosis requires that neutrinos have mass, dispelling the long-held notion that they were massless. The academy said the discovery "has changed our understanding of the innermost workings of matter."

"Yes, there certainly was a Eureka moment in this experiment when we were able to see that neutrinos appeared to change from one type to the other in travelling from the Sun to the Earth," McDonald told reporters by telephone from his home in Kingston.

Neutrinos, along with quarks and electrons, are the most basic particles that make up matter "particles that we don't know how to subdivide any further," McDonald told CBC News in an interview. Among those three types of basic particles, neutrinos are the hardest to detect.

McDonald managed to study them with a detector the size of a 10-storey building deep underground at SNOLAB, where most other particles that could cause false signals can't penetrate.

He added that scientists still want to know what the actual mass of the neutrino is, and whether there are other types beyond the three currently known.

McDonald said being named winner is a "very daunting experience, needless to say."

"Fortunately, I have many colleagues as well who share this prize with me," he added.

McDonald is retired from teaching, but he is still involved in research.

"In fact, we're just about to turn on an experiment to attempt to observe particles called dark matter particles. We'll have ten times better sensitivity than other experiments have had so far...and that may lead to another Eureka moment, we hope," he said in an interview with CBC's Heather Hiscox.

Born in Sydney, N.S., in 1943, McDonald earned bachelor's and master's degrees from Dalhousie University. He got his PhD in physics from California Institute of Technology in 1969.

He worked for Atomic Energy of Canada from the late 1960s until 1982, when he moved to Princeton University for seven years.

He has been at Queen's since 1989 and has been a professor emeritus since 2013.

Learn more at

Return to our Significant Scots page


This comment system requires you to be logged in through either a Disqus account or an account you already have with Google, Twitter, Facebook or Yahoo. In the event you don't have an account with any of these companies then you can create an account with Disqus. All comments are moderated so they won't display until the moderator has approved your comment.

comments powered by Disqus