**Topics from today's class**:

- Knots
- The unknot, trefoil knot, figure eight knot
- (Regular) projections
- Crossing number

**Homework**:

- Don't turn in: 1.3 (try using KnotPlot to show this)
- Turn in: 1.4, 1.5
- Turn in: we didn't give a mathematical definition of a knot (and if you look at the text, the author doesn't either). Try to give a rigorous definition of the term knot (do your best).

**Presentations**:

- I'll take volunteers

**Read for next class**:

- Sections 1.1 and 1.2

**Announcements**:

- Don't forget to answer the two questions below.
- There are some beautiful pictures on the KnotPlot website.