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The Radiation of a Fast Electron

The looping white lines of this image are a trail of water droplets created by a single electron traveling through a super-saturated vapor in a device called a cloud chamber. Cloud chambers made the movement and interactions of subatomic particles visible to the human eye. Many important discoveries in nuclear physics were made by looking at thousands of images like this one and recognizing new patterns.


Radiation Laboratory, Berkeley, California
1940
Source: An Atlas of Typical Expansion Chamber Photographs by W. Gentner, H. Maier-Leibnitz, and W. Bothe