Opening of the SNO Exhibit at the Museum of Science and Technology

Thursday, February 17, 2005

Art McDonald, SNO Director, University Research Chair in Physics, Queen's University

We in the Sudbury Neutrino Observatory scientific collaboration are very pleased that our project has been chosen as an exhibit at the Museum of Science and Technology during the Year of Physics 2005. This year has been chosen to commemorate the major advances in the fundamental laws of physics that were represented by Einstein's seminal papers of 1905. Our own scientific objectives have also been to provide new insights on the most fundamental laws of physics. These insights are at the most microscopic level as well as at the furthest reaches of our Universe in space and time. With SNO and the new SNOLAB International Underground Facility currently under construction, we are able to use substantial Canadian natural advantages to push the boundaries of our knowledge in physics, astrophysics and the evolution of our Universe.

SNO is a Canadian-led international scientific project sited 2 km underground in INCO's Creighton mine near Sudbury, Ontario. It uses 1000 tons of heavy water on loan from AECL, with the cooperation of Ontario Power Generation, to detect neutrinos produced copiously in the Sun. Neutrinos are sub-atomic particles that are among fundamental building blocks of nature. Along with electrons and quarks, they are the set of fundamental particles that we do not know how to subdivide further. They penetrate through vast amounts of material and can therefore pass through the Sun and Earth, to be observed in the SNO detector underground. The rock above our detector stops other cosmic particles that otherwise would make our detector glow like the Northern Lights.

With the unique properties of heavy water, the SNO scientific team has been able to show clearly that electron-type neutrinos change to the other two types in transit to the Earth. This observation requires that the so-called Standard Model of Elementary Particle be changed. Theorists are already very busy working on this problem. For many months in 2003, three SNO scientific papers were the most cited papers in all of physics. The SNO results have also cleared up a long-standing problem known as "The Solar  Neutrino Problem" and have confirmed that current models of the energy generation processes in the Sun are very accurate.

The SNO results, taken together with other international measurements have defined many previously unknown properties of neutrinos, setting limits on their mass that restrict the contribution of neutrinos to the total mass of the Universe. This contribution is in agreement with the remarkable present picture of how the Universe has evolved and how it is composed (known as Cosmology). Measurements during the past 10 years have developed a picture of a Universe composed of about 5% normal matter (of which we are composed), 25% Dark Matter (of which neutrinos are a small part, but the other particles are unknown) and about 70% Dark Energy, (which has been inferred from the observation of an extra term in Einstein's Theory of Gravity).

With the new SNOLAB, at the same underground site made possible through the tremendous cooperation of INCO, Canadian and international scientists are lining up for future experiments. They want to use this deepest site in the world to look for the particles making up "Dark Matter" and to look for rare forms of radioactivity that can further describe neutrino properties. These measurements can perhaps confirm why our present Universe is composed of matter, instead of partly matter and partly anti-matter as it was during the Big Bang.

These questions that we are addressing here in Canada with the latest technology are among the most fundamental ones in physics and cosmology. Einstein would love them as they are in the most direct line to the "Theory of Everything in our Universe".

We are very pleased with our ability to provide educational opportunities for students working at the frontiers of science and technology at our partner institutions Queen's, Carleton, Laurentian, Guelph, UBC and U de Montreal. I would like to introduce Prof. David Sinclair of Carleton University, the Director of SNOLAB, Prof. Doug Hallman of Laurentian University, our Director of Communications who was very much involved in this exhibit, and Dr. Alan Poon of Lawrence Berkeley National Laboratory, representing our international partners. I would also like to thank INCO, represented by Mr. Brian Maynard, Manager of Creighton mine and Mr. Cory MacPhee INCO Communications Director for their contributions to the exhibit and the event today, for the tremendous cooperation we have received from INCO over many years and for the future commitment that makes SNOLAB possible. I would also like to thank our principal sponsor, NSERC, represented here by Executive Vice President Nigel Lloyd, for their ongoing support for the SNO project that has made the scientific success possible.

We thank the Museum of Science and Technology and their highly professional team their work on this exhibit and for choosing our work to highlight during this important Year of Physics. We hope that the exhibit will inform the general public about this important science happening here in Canada and perhaps will inspire future Canadian students to follow a career in science.