Conchospiral

In cylindrical coordinates, the conchospiral is described by the parametric equations: :r=\mu^t a :\theta=t :z=\mu^t c. The projection of a conchospiral on the (r,\theta) plane is a logarithmic spiral. The parameter \mu controls the opening angle of the projected spiral, while the parameter c controls the slope of the cone on which the curve lies. ==History==

The name "conchospiral" was given to these curves by 19th-century German mineralogist Georg Amadeus Carl Friedrich Naumann, in his study of the shapes of sea shells. ==Applications==

The conchospiral has been used in the design for radio antennas. In this application, it has the advantage of producing a radio beam in a single direction, towards the apex of the cone. ==References==