A Canadian was honoured today with a Nobel Prize in Physics, but we bet you won’t be able to figure out what his big discovery actually means.
Arthur McDonald is the co-winner (alongside Japanese scientist Takaaki Kajita) for discovering neutrino oscillations and revealing that the particles can change identities. This discovery has apparently “changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe,” according to the Royal Swedish Academy of Sciences.
Clearly, it’s super-important. But do you have any idea what it actually means?
We certainly didn’t. So even though this story has been trending nationwide for almost a full day now, we have a sneaking suspicion most people don’t know what they’re actually sharing or why they should be proud. So we’re breaking it down for you here.
Let’s start with the basics: neutrinos are the second-most abundant particle in the universe, but very little is known about them. Think of the particles like electrons (which you learned about in high school), except they don’t carry an electric charge. Most of the neutrinos that exist here on Earth are the result of nuclear reactions that took place on the Sun, and they are constantly streaming onto our planet.
In the late 1990s, physicists were left scratching their heads when they realized that their Earth-based detectors were picking up far fewer neutrinos than their theoretical models had predicted. One of the detectors is based in Ontario, Canada (run by McDonald), while another was located in Japan. At the time, many scientists just believed the particles were disappearing.
That all changed in 1998, when Kajita’s team reported that many of the neutrinos they had caught in Japan had taken on a new identity from their earlier space appearance. See, when neutrinos are released, they occasionally collide with a few atoms during their journey to Earth. The team found that somewhere in all these crashes, some of the neutrinos had actually changed form.
Three years later, a group led by McDonald found neutrinos in Ontario had also flipped from their expected identity. But undertaking a metamorphosis like that would require the particle to have mass (something previously believed to be false), and it would also explain why Earth’s detectors weren’t detecting them.
“It was a real eureka moment,” McDonald says in the video, above. “The result was very clear, with very little possibility that neutrinos were doing anything other than changing their type.”
So what do these discoveries ultimately mean? It means everything we knew about the universe has been turned upside-down. The discovery contradicts the Standard Model of Particle Physics (which requires neutrinos to be massless), but more importantly, it changed calculations around the actual nature of the universe, including its eternal expansion.
The Big Bang theory stipulates that the universe is ever-growing as a result of the massive blast that set it all in motion. But if this discovery proves that notion to be false, well, that would be quite a huge deal indeed.
We bet you’d never guess that was going on when all you had to work with was “neutrino oscillations.”
Congratulations, Professor McDonald! Way to shake the foundation of our whole universe.