The sun was thought to produce electron neutrinos only, and if these particles were somehow morphing into the other two flavours as they travelled through space, it could explain the anomaly.
The Nobel judges awarded the Nobel physics prize jointly to Takaaki Kajita of Japan and Arthur B McDonald of Canada ‘for the discovery of neutrino oscillations, which shows that neutrinos have mass’.
“It is a discovery that will change the books in physics, so it is really a major discovery”, said Barbro Asman, a Nobel committee member and professor of physics at Stockholm University. Before their discovery, it was generally believed that these elementary particles did not have mass.
“It has become obvious that the Standard Model cannot be the complete theory of how the fundamental constituents of the Universe function”. The depth at both facilities is meant to shield the observatories’ neutrino detectors from cosmic radiation at the earth’s surface, which can cause false readings.
Only light photons – which are without mass – are more numerous. And ongoing experiments are delving into whether there are other types of neutrinos beyond the three clearly observed.
Trillions pass through us and the Earth every second but leave no evidence of their passing.
“By our measurements we were able to confirm with great accuracy calculations of how the Sun burns by fusion processes,” McDonald said.
“Yes, there was that Eureka! moment”, he said.
Since the Nobel Prizes were first handed out in 1901, 198 laureates have received the physics award. The experiment demonstrated that neutrinos from the sun were not disappearing on their way to earth and were captured with a different identity when arriving at SNO.
Yet for more than 80 years, physicists have only had a glib understanding of how they worked.
The finding that they transform themselves has “changed our understanding of the innermost workings of matter”, said the academy.
Of course, they also already know that neutrinos only very rarely actually interact with matter as they can easily slip directly through an entire block of lead the length of an entire light-year!
“Reuters put this (project) on the list of possible Nobel Prize winners back in 2007, so it’s something that the (academic) community has been speaking about for quite a few years”, he said. According to the Standard Model of particle physics there are three types of neutrinos – electron-neutrinos, muon-neutrinos and tau-neutrinos.
The winners get to split the $960,000 prize, along with the bragging rights of course.
And China’s Tu Youyou discovered a drug that has significantly reduced the mortality rates for patients suffering from malaria, so she will also share in the prize.
Each recipient receives a gold medal, a diploma and a monetary award, which is decided by the Nobel Foundation.