At the European Organization for Nuclear Research (CERN) in Switzerland, scientists accelerate protons close to the speed of light to study the fundamental building blocks of nature. The high-energy collisions between protons produce a variety of exotic particles, such as quarks, leptons, and muons. These infinitesimally small objects can only be observed by the trails they leave in chambers filled with liquid hydrogen. High-speed cameras capture the tiny bubbles created by these subatomic particles, providing the only evidence of their ephemeral existence.