# [2009-03-16] Big bouncing baby blue Buckyball

A few times in my experiments with creative reuse I've had some very satisfying *Aha!* moments. One of these was my independent discovery of the now widely-known fact that many disposable soda bottle caps will fit the threads of a standard medium-base lightbulb. Another was my finding, back in 2004, that this flexible blue plastic conduit (or "ENT" = Electrical Nonmetallic Tubing), which I find very beautiful, fits perfectly into 3/4" PVC pipe fittings. Using only conduit, 3/4" PVC tees, and PVC cement, I was able to construct the giant bouncing blue buckyball model shown above. It is slightly more than three feet in diameter and bounces delightfully when dropped on the floor.

Its construction led to the realization, on my part, that any geodesic system could be approximated by a construction toy having three-way connections and flexible members. Although many geodesic graphs call for nodes with greater than three-way connectivity, any such connection can be approximated by a circle constructed only using three-way connections, as shown below. In fact, my blue sphere wasn't undertaken with the intent of modelling a buckyball, rather it was an approximation of an icosahedron in which each 5-way joint was replaced by a 5-prong circle. I only realized after the fact that this method incidentally modelled C60 buckminsterfullerene.

Reader idyllthyme sent in these photos of a sphere he made using this method. He covered it with aluminum foil and used it to wrap a gift for a friend's son's birthday. He left a small port open in one side so James could climb inside to retrieve his present. Makes me wish I were child-size again!

last modified 2009-04-14