Pappus Chain

1,861 views · Published 24 July 2008 · 0:17 · Indexed 8 November 2026

Channel: Wolfram · 2008 · Education

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The Pappus chain extends across at least two millennia of mathematics. Its origins trace back to the ancient Greek mathematician Archimedes and his studies of circles inscribed within the figure of an arbelos (or shoemaker's knife). The inversive geometry trick for efficiently computing the positions of pairwise tangent inscribed circles, or a Pappus chain, is apparently a modern invention. The Apollonian gasket or curvilinear Sierpinski sieve is constructed by the same iterative process of inscribing a circle in triplets of tangent circles. Thus the Pappus chain construction anticipates the class-2 nested behavior of many elementary cellular automata.

By Christopher Haydock (Applied New Science LLC)

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