What is a self-illustrating phenomenon? A self-illustrating phenomenon is an image that is generated automatically as a result of an experiment. More importantly, it is an image that exposes the phenomenon behind the observation. It often represents an answer to a question.

Here is an example. Ernst Chladni, a musician and amateur scientist, found a way to make visible the vibrations caused by sound waves. He covered metal and wooden plates with sand and ran a violin bow against them. When the plate vibrates, sand collects at the stationary nodes, having been shaken from the moving regions. These nodes are the zero-crossings of the standing wave that produces the sound. Being a musician, he was interested in the theory of sounds and he used the tools at his disposal, in this case a violin bow.


[1] Chapter 6, Science since Babel: Graphs, Automatic Recording Devices and the Universal Language of Instrument, In Instruments and the Imagination, T. L. Hankins and R. J. Silverman, Princeton University Press, 1995.

[2] p. 134, The Scientific Image, H. Robin

Copyright© 2005 by Pat Hanrahan