A cloud chamber is a scientific device used to visualize the paths of charged particles, such as electrons or alpha particles. It consists of a sealed environment filled with a supersaturated vapor, typically of water or alcohol. When a charged particle passes through the chamber, it ionizes the vapor, creating trails of tiny droplets that reveal the particle's trajectory. Invented by C. T. R. Wilson in the early 20th century, cloud chambers have been instrumental in particle physics and radiation studies. They allow scientists to observe the behavior of subatomic particles and contribute to our understanding of fundamental forces in the universe.