The simplest spiral, a line, can be created with the Shape tools on the Insert tab. Just choose the Scribble tool and draw a spiral freehand on the slide. If you want to create a more substantial ...

Starting with the observation that shell spirals are logarithmic spirals, many people automatically assume that, because the golden ratio can be used to draw a logarithmic spiral, all shell ...

Physics determined ammonite shell shape Date: October 10, 2014 Source: CNRS (Délégation Paris Michel-Ange) Summary: Ammonites are a group of extinct cephalopod mollusks with ribbed spiral shells ...