Paddleball Tour
Paddleball Dynamics

This is a tour through the Poincaré sections of a ball
bouncing between a fixed upper and oscillating lower paddle. The phase
portrait shows velocity on the horizontal axis and position on the
vertical axis, and Poincaré sections are taken at 12 equally spaced time
intervals during one drive cycle. As we move through one drive cycle,
we see the stretching and folding of the attractor as the ball is
periodically given energy (stretch) and forced to change direction
(fold).