Wilson was born in Glencorse, Scotland, on February 14, 1869. However, his family moved to Manchester in 1873 when his father died. Wilson entered Owens College in Manchester at the age of fifteen and graduated with a bachelor of science degree in biology three years later. He then enrolled at Sidney SussexCollege, Cambridge, and earned his doctorate in physics in 1892.
An important event in Wilson's life occurred in 1894. He spent a few weeks atthe observatory on top of Ben Nevis, the highest mountain in Great Britain.Wilson was fascinated by the process of cloud formation that he observed every day at the observatory. He decided to find ways of imitating the process inthe laboratory.
Wilson's method was to allow moist air within a glass container to expand quickly. As the air expanded, it became cooler and tiny droplets of moisture condensed as artificial clouds. Wilson observed that the amount of condensationwas greatly reduced if all dust was removed from the container. Yet, some condensation occurred even in a completely dust-free environment.
Wilson concluded that ions within the container served as nuclei for the condensation of water droplets. He tested this idea in the late 1890s by exposingthe container to X-rays and nuclear radiation. He found that the amount of condensation greatly increased in the presence of either type of radiation.
Thus was born the principle of the cloud chamber. By 1911, Wilson had refinedthe concept. Particles applied to the cloud chamber formed ions that servedas nuclei for the condensation of water droplets. Magnetic fields surroundingthe cloud chamber caused charged particles to travel in curved paths. The shape of such paths reflect the mass and charge of particles that pass throughthe container. Using this device, nuclear physicists could identify a host ofotherwise invisible subatomic particles by their "vapor trails." J. J. Thomson called the cloud chamber a device of "inestimable value to the progress ofscience." For his invention, Wilson was awarded the 1927 Nobel Prize in physics.
Wilson made a second important discovery. He observed that an electroscope completely shielded from surrounding electrical fields still loses its charge slowly. He predicted that this loss of charge was due to some kind of radiation from "outside our atmosphere." This idea was the first hypothesis of the existence of cosmic radiation.
Deeply attached to his Scottish homeland, Wilson lived the last twenty-five years of his life there. He died in Carlops, Peeblesshire, on November 15, 1959.