E.M.S. Hitzer

**The Geometry of Light Paths for Equiangular Spirals**

*Advances in Applied Clifford Algebras* **9**(2), 261 (1999).

**Abstract:**
First geometric calculus alongside its description of equiangular
spirals, reflections and rotations is introduced briefly. Then single
and double reflections at such a spiral are investigated. It proves
suitable to distinguish incidence from the *right* and
*left* relative
to the radial direction. The properties of geometric light propagationinside the equiangular spiral are discussed, as well as escape conditions and
characteristics. Finally the dependence of right and left incidence from the
source locations are examined, revealing a well defined inner
*critical*
curve, which delimits the area of purely right incident propagation.
This critical curve is self similar to the original equiangular spiral.

[Postscript] 751k, gzip compressed

[Geometric Calculus Japan index]