Zöllner's Illusion

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Zöllner illusion

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A few words.

Depending on the relative position of stationary and rotating lines, the former do not sometimes appear parallel, although they always are (F. Zöllner, 1860.)

References

A. Seckel, The Art of Optical Illusions, Carlton Books, 2002, #125
The Mind's Eye, Readings from SCIENTIFIC AMERICAN, W. H. Freeman and Company, 1986

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