The University of Queensland

PhD Journal Club Talk

“Square dancing with rational tangles”

By Duncan Mortimer

11am, Tuesday 14^th October, 2008

Priestley Building, room 706

Abstract:

In 1967, John Conway finally got around to publishing some work he did in high school, developing a method of enumerating knots.

Specifically, he formally introduced the idea of the "Tangle". Being Conway, with games seldom far from his mind, he also invented a new form of mathematical morris* dancing, with a group of four mathematicians moving through intricate motions while holding bits of rope to tie complicated knots. And then, being Conway, he'd show off by choreographing the dance in such a way that the messy tangle of ropes became untied. In this lecture, I'll show you how to wow your mathematically inclined friends, confuse your non-mathematically inclined friends, and amuse small children with a demonstration of Conway's "boot-scootin' knot-tying square dance", and as an added extra, I'll even prove why it works, building on the ideas Peter so deftly introduced over the last two weeks.

Assuming you're not all bored to death of me by then, I'll continue the following week with a discussion of how tangle- and knot-theory can give us insight into why our DNA doesn't end up in a great big mess.

* don't worry: this lecture will not contain any bells, braces or disturbing dress sense: http://tinyurl.com/5yh7kj

The setting for these talks is quite informal as we are all non-experts. We aim to spark a good discussion on an interesting topic, so all are invited to attend. Any queries? Email Katrina: keh@maths.uq.edu.au.