Dara Stepanek
Chapter 9: Knots, Topology, and the Universe
HW # 11
Due: Thursday 4/28
1. Draw the transformation of the following linked ring puzzle into an unlinked ring figure
using only stretching and bending.
2. a) What is a practical purpose for a Möbius band?
b) Create two Möbius bands. On one, demonstrate nonorientability. Cut the other band in half;
describe and explain what happens. Attach both Möbius bands to your homework.
3. What is the difference between a knot and a tangle? Why must knots be in 3-D?
4. How do you create a cross-cap and what is the moral of this procedure?
5. Describe how symmetry is the binding principle that brings geometry and physics together.
Give an example of a physical law that holds to this principle.