Cocktail Party Physics: chamber of secrets

By 1910, Wilson had figured out he could use his cloud chamber device to detect charged particles, since they would leave a trail of ions — and water droplets — as they passed through the gas in the chamber. He took the very first photographs of the tracks left by alpha and beta rays, not to mention evidence of how individual atoms and their electrons interacted. Both alpha and beta particles have distinctive tracks: the former is broad and straight, while the latter is thinner and more easily deflected by collisions with other particles. Apply a uniform magnetic field across the cloud chamber, and positively and negatively charged particles will curve in opposite directions. Wilson chambers became all the rage in particle physics, leading to all kinds of exciting discoveries. The discovery of the positron in 1932 at Caltech occurred thanks to a Wilson chamber, garnering physicist Carl Anderson a Nobel Prize in the process. Wilson himself snagged a Nobel, too, for his invention of the cloud chamber.

Last time I visited TRIUMF I saw the cloud chamber they had added to the lobby, and I thought it would be so easy to mount a webcam to one of these and broadcast live images. As far as I know, nobody has done this.