Pictures on the cover were created by Jordi Vives Nebot (Dept. de Fisica Fonamental, Universitat de Barcelona, Diagonal 647, E-08028, Barcelona, Spain). They represent sections x + ye12 + ze1 of two Julia-type 3-dimensional Clifford fractals viewed from an isometric perspective.  Each image is a result of 10 iterations of the map c -> c2 + b, where c and b are elements of the Clifford algebra Clp,q, p+q=2.  Convergence of the resulting sequences of Clifford elements was determined by using a spinorial norm (the scalar part of the Clifford number times it Clifford-conjugate). The following metrics and base points b have been used to create these images:

Last revised: Feb 14, 2002