Two kilometers under Sudbury in Ontario, Canada, one can find a vast physics laboratory that is unraveling the deep secrets of the universe. In the sheltered darkness deep into the Canadian Shield, this underground den aids physicists venture into cutting-edge science, such as the search for elusive dark matter.
The Sudbury Neutrino Observatory, the world’s deepest clean underground lab, is a high-tech facility allowing scientists to study neutrinos.
In a live public lecture by the Perimeter Institute held April 13, SNOLAB director Dr. Arthur McDonald — a Nobel laureate and practically a rockstar in the physics world — delved on their work detecting these subatomic particles that are among the building blocks of the universe.
Neutrinos are subatomic particles dubbed “ghost particles” due to their notoriously hard-to-catch nature. Created when the sun shines, trillions of them flow through the human body and right through the planet every second, seemingly as naturally as sunlight beams through one’s windows.
McDonald calls them “astronomical messengers” as they can inform us of the distant reach of the universe, as well as the explosion of distant stars and the inner processes of the solar system’s own sun.
In 2002, McDonald’s team demonstrated that neutrinos move from one “flavor” to another, have three types, and contain mass.
This evidence requires modifying the Standard Model for elementary particles, as well as confirms solar model calculations with great accuracy, states the Perimeter Institute of the measurements that won McDonald the 2015 Nobel Prize in Physics and 2016 Breakthrough Prize in Fundamental Physics.
“He led a large team of people that cracked the mystery of the solar neutrino problem – basically about how our sun actually shines,” quantum physicist Damian Pope of Perimeter tells the National Post. “That was one of the biggest mysteries in physics for many decades.”
Pope explains that neutrinos are highly elusive and sensitive, and it is very difficult to observe them because they barely interact with anything. This led the SNOLAB experiment to be well-shielded, going two kilometers underground with two kilometers of rock protecting from all types of outside particles interfering with the neutrino signal.
Also making these particles slippery are their three different types, allowing them to change identities in a way that can be compared to how a chameleon lizard changes its hue depending on the background.
Knowledge of neutrinos, Pope asserts, will tell humans about the entire universe and, on a more practical sense, pave the way for more discoveries and tech innovations.
The lab, for instance, is engaged in around half-dozen experiments on dark matter, which are also very difficult to find and demands a very isolated experiment. If dark matter indeed exists, its particle will likely collide with another particle in the lab, giving off a burst of energy that scientists can detect.
Read updates and Q&As from the McDonald’s live talk, which happened at 7 p.m. EDT and was live-blogged and followed using the hashtag #piLIVE.