The high profile Nobel Prize in Physics in 2015 has been granted to Japanese scientist Takaaki Kajita and Canadian scientist Arthur B. McDonald on October 6, “for their key contributions to the experiments which demonstrated that neutrinos change identities”, a metamorphosis which requires that neutrinos have mass.

Neutrinos have long been deemed massless. “The discovery has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe,” says the The Royal Swedish Academy of Sciences.

While we laud the achievements of the physicists, some might wonder, “how are particles as small as this observed and studied?”

Let us take a look at the Sudbury Neutrino Observatory located in Canada— the exact place where the Nobel-winning discovery was made in 2001.

The observatory is built 2,100 meters underground. The main part of it is a ball-shaped contain with a diameter of 12 meters with 1,000 tons of heavy water in it. The heavy water would interact with solar neutrinos.

Another observatory is the Super-Kamiokande under Mount Kamioka in Japan— the place where the statement made by aforementioned Sudbury Neutrino Observatory was confirmed in 2002.

Located 1,000 meters underground, Super-Kamiokande consists of a cylindrical stainless steel tank that is 41.4 m (136 ft) tall and 39.3 m (129 ft) in diameter holding 50,000 tons of ultra-pure water.