Chapter 7: Mechanisms in Programs and Nature

Section 3: Randomness from the Environment

Spark chambers

The sensitivity of sparks to microscopic details of the environment is highlighted by the several devices which essentially use them to detect the passage of individual elementary particles such as protons. Such particles leave a tiny trail of ionized gas, which becomes the path of the spark. This principle was used in Geiger counters, and later in spark chambers and wire chambers.

From Stephen Wolfram: A New Kind of Science [citation]