TITLE: Visual pictures of rotation and torsion
QUESTION [7 upvotes]: In vector analysis / differential geometry we have rotation and torsion. The formalisms are certainly well known. But how could I best explain the geometric pictures and their difference (as a coach of an exercises group of bachelors who just started this topic)?

REPLY [7 votes]: Here is a beautiful animation created by Urs Hartl at Universität Münster:
   
Urs created this in Maple. The worksheet (.mw), which allows user-input 
of curves, is here.