Hyperboloidal Tunnel, One-Sheeted Hyperboloid

####Hyperboloidal Tunnel, One-Sheeted Hyperboloid

##### Added a body with a hole at the top so one can leave a pencil in it (Thanks to Dr. Kapur in the SIU Honors Program)

The hyperboloid (of one sheet) is an interesting ruled surface. Using two sticks (such as pencils), one can model it in the classroom. It is aesthetically appealing and mathematically rich. I got this design idea after a recent iteration of my **spin-the-cube** lesson. It is pedagogically dissected to show different aspects of the structure. It comes with two pieces. The top part is a hyperboloidal chamber with a 120-degree and a 90-degree cut, revealing both the surfaces and curves. The bottom part functions like a turntable demonstrating the ruled nature of the hyperboloid. The ruling is either a segment of a pencil, up to 100 mm, or the integrated bar.

####References

1. Bu, Lingguo (2021) "The Spinning Cube: An Algebraic Excursion," The Mathematics Enthusiast: Vol. 18 : No. 1 , Article 5.