One of the standard exercises of computer science is called the firing-squad problem, which asks how a group of soldiers without a leader can arrange to fire their weapons simultaneously. A number of ingenious solutions have been worked out, involving multiple signals passed up and down the line and forming intricate fanlike patterns as they reflect and propagate. The problem was originally intended to illuminate some of the difficulties of synchronizing the multiple processors of a distributed computing system, but the solutions can clearly be applied to the synchronization of seashell patterns as well. By mathematical criteria, the firing-squad solution might well be judged the more elegant, if only because it accomplishes the task with fewer resources. But the central oscillator has biological plausibility and precedent on its side.
Nature often seems blandly content with the ugly answer that works.
Many more shell patterns are studied and simulated in these pages, including some where dual oscillators are unquestionably present, since they both leave visible trails. But I must leave off describing shells in order to leave room for illustrating a few of them. The Algorithmic Beauty of Sea Shells. With contributions and images by Przemyslaw Prusinkiewicz and Deborah R. Fowler. Accompanied by simulation software for computers running the MS-DOS operating system.