Holger Dullin University of Sydney Chaotic dynamics of the triple pendulum Wednesday 5th August 14:05-14:55pm, Eastern Avenue Lecture Theatre. The chaotic triple pendulum is a prime example of a mechanical system that exhibits chaotic behaviour. A new triple pendulum has been built for the School of Mathematics over the winter break by the mechanical workshop of the School of Physiscs. In this talk I will demonstrate the amazing behaviour of the triple pendulum and discuss some aspects of the corresponding ordinary differential equations. Depending on the masses of the pendula the system can change behaviour from completely integrable to chaotic. The degree of chaos also depends on the total energy. For infinite energy (or without gravity) an additional constant of motion appears. Important aspects of the transition from low energy to high energy can be understood in terms of the changes of the topology of the corresponding energy surface. I will show how to construct global Poincare sections in these energy surfaces (for the double pendulum).