| Visitors watch
the paths of high speed charged particles as they are revealed by
condensing clouds in this cloud chamber.
The main bulk of the exhibit is a refrigeration unit which keeps
the air in the chamber supersaturated with alcohol. High speed charged
particles are produced by cosmic rays. These high speed charges
ionize the air along their tracks. The ions in the air then act
as condensation nuclei for the alcohol. so droplets of alcohol form
clouds along the tracks of the charged particles. As the droplets
grow they settle out of the chamber, which is then ready for more
Some of the charged tracks are produced by particles of anti-matter.
The exhibit shows that we are bombarded by particles all the time.
The charged particles tracing out the cloud paths are the basic
building blocks of the universe.