The double-tipping nullhomotopy
by David Pengelley and Daniel Ramras

Here we collect animations and demonstrations supplementing our article "How efficiently can one untangle a double-twist? Waving is believing!" (Here is a link to the published version, from the Mathematical Intelligencer).

Animations and Demonstrations:

• A video showing eight incremental stages of nullhomotopy. 
  
  
• Virtual reality demonstrations of the nullhomotopy, designed by the MEGL lab at George Mason University, are available here (scroll down). Note that while these demonstrations are designed for the Oculus Rift, they are also quite fun to play with on a desktop computer, and are less likely to induce vomiting when viewed that way.  
  


• The Belt Trick. A video demonstration of the belt trick.
  


• The Candle Dance. A video demonstration of the candle dance.
  
  
• Waving is Believing! A video explaining how to "wave" a nullhomotopy of the double twist with your right hand.
  
  
• Simultaneous Waving. A video showing 9 simultaneous "waves" of the double-tipping nullhomotopy.

If you enjoy these animations, you should also check out the work of Greg Egan and Bob Palais!

The double-tipping nullhomotopy