Chinese Handcuffs
The Geometer’s Sketchpad — The investigation below follows an image that I created in the 20th century with use of The Geometer’s Sketchpad. That software is no longer marketed, but happily it is still distributed, courtesy of McGraw-Hill. I still use it nearly every day. It can be downloaded at this link. Handcuff.gsp — Download this Geometer's Sketchpad document. The sketch gets this name because it resembles a little bauble I used to see handed out as a prize at carnivals. We would call them Chinese handcuffs, but they may have had other names in elsewhere. It is an open cylindrical object, made from woven rushes. If you stick a finger into each end and try to pull them apart, it will squeeze the fingers, preventing them from separating. I still find this Sketchpad image somehow mesmerizing, but it seems not to have that same effect on everyone. The only comment I recall in all these years came from someone condemning the cultural appropriation in the title. Well, at least I got that small measure of satisfaction from it. Some recent activity from the developers of Sketchpad has resulted in Web Sketchpad, enabling readers to view the same document right here on the web. I still recommend the genuine article, but it is not necessary here. Rather than lead anyone around by the nose, I think it might be more interesting to let the students do their own investigations. There are applications for geometry, trigonometry, and probability. It does not look like much when you first open the file, just one point and two buttons. Leave the Show Construction button alone to begin with. Just click the Animate button and watch the show. |