Neutrino cubes and killer kitties.
Neutrinos are some of the most abundant elementary particles in the universe, but they are also very difficult to detect, as they have no mass (or a maybe a strange kind of very small mass, according to newer theories). Neutrinos can be captured in large tanks such as the two under construction at CERN. The cubes will be filled with argon and cooled to -184 °C. These 12 x 12 m tanks are just the forerunners of the more extensive experiment called DUNE, which will search for neutrinos in a tanks 20 times bigger, from 2026.