Art McDonald (born 1943) speaking about the science of the Sudbury Neutrino Observatory (SNO) at CERNs (European Organization for Nuclear Research) main auditorium in 2017. McDonald obtained his PhD in physics in 1969 from the California Institute of Technology. In 2015, he was awarded the Nobel Prize in Physics for the discovery of neutrino oscillations and for demonstrating that neutrinos have mass. In this speech, he discussed how the scientists and technicians involved in building the SNO took over 70,000 showers to ensure a completely clean and uncontaminated laboratory. As director of the SNO, he hopes to detect solar neutrinos through their interactions with a large tank of heavy water.