June 25, 2013

Pentagons and Game Balls

The game of sepak takraw, a popular form of kick volleyball in Southeast Asia, uses a woven ball that, in its simplest form, has 12 pentagonal holes and shows a weaving pattern with 20 intersections. The twelve pentagons remind me of a regular dodecahedron, one of the Platonic solids.

Traditionally made from rattan, such a ball may be constructed from six long strips (instructions), with five strips defining the pentagonal holes and a sixth strip forming a closed loop that wraps around twice (video).

This ornamental model, with woven strands intersecting to form pentagons atop a glass sphere, shows the basic geometry underlying a woven sepak takraw ball.

More complicated weavings produce triangular patterns on the ball's surface (below).

The two examples shown above are part of a display of artistically crafted woven spheres in the lobby lounge of the AT&T Executive Education and Conference Center at the University of Texas at Austin. I couldn't help but be reminded of sepak takraw balls when I first saw the display.

Unfortunately, I couldn't find any information about these intriguing models, and would love to know more about them.

Photos by I. Peterson

1 comment:

universalibrarian said...

Thank you for the link to the paper. Here are another set of instructions for a different but similar object. Very satisfying to make with packing strapping.
I have seen woven balls that are the dual of this one but have not found or figured out instructions to them yet. They can be expanded to have a completely woven surface where this one can't as easily.